Transition Parameters Research Articles

Percolation transitions in edge-coupled interdependent networks with directed dependency links

We propose a model of edge-coupled interdependent networks with directed dependency links (EINDDLs) and develop the theoretical analysis framework of this model based on the self-consistent probabilities method. The phase transition behaviors and parameter thresholds of this model under random attacks are analyzed theoretically on both random regular (RR) networks and Erdös–Rényi (ER) networks, and computer simulations are performed to verify the results. In this EINDDL model, a fraction β of connectivity links within network B depends on network A and a fraction (1 − β) of connectivity links within network A depends on network B. It is found that randomly removing a fraction (1 − p) of connectivity links in network A at the initial state, network A exhibits different types of phase transitions (first order, second order and hybrid). Network B is rarely affected by cascading failure when β is small, and network B will gradually converge from the first-order to the second-order phase transition as β increases. We present the critical values of β for the phase change process of networks A and B, and give the critical values of p and β for network B at the critical point of collapse. Furthermore, a cascading prevention strategy is proposed. The findings are of great significance for understanding the robustness of EINDDLs.

The nonlinear nexus between renewable energy consumption and economic growth in OECD countries: evidence from PTR and PSTR estimates

PurposeToday, the increasing use of fossil fuels, energy security, concerns and the great importance of achieving sustainable economic growth underscore the urgent need to transition to a green energy system as soon as possible. To shed light on the relationship between the economy and renewable energy, this study assesses the nonlinear relationship between renewable energy consumption and economic growth for 24 OECD countries between 1990 and 2015.Design/methodology/approachThe authors apply two nonlinear models: panel threshold regression (PTR) and panel smooth transition regression (PSTR).FindingsThe results show that the positive effect of renewable energy consumption on economic growth is conditional. On the one hand, the results of the nonlinear PTR model yielded a threshold value for renewable energy consumption of about 251.17. Below this threshold, the authors find a negative impact of renewable energy consumption on economic growth. However, above this threshold, renewable energy consumption becomes a favorable source of economic growth. Using the nonlinear PSTR model based on the gamma transition parameter of 2.014, the transition from low renewable energy consumption regime to higher is abrupt.Originality/valueReferring to previous studies analyzing linear causality between renewable energy and economic growth, most of the results show various mixed and non-stable effects over the study period. The contributions of this study consist in conduct a series of empirical tests of the nonlinear effects of renewable energy use on economic growth using two nonlinear approaches such as the PTR and PSTR models. If the authors show that such a relationship is nonlinear, it is essential to check whether the transition from one weak regime to another strong regime is abrupt or smooth, using the PSTR approach.

Test and re-test reliability of optimal stimulation targets and parameters for personalized neuromodulation.

Protocols have been proposed to optimize neuromodulation targets and parameters to increase treatment efficacies for different neuropsychiatric diseases. However, no study has investigated the temporal effects of optimal neuromodulation targets and parameters simultaneously via exploring the test-retest reliability of the optimal neuromodulation protocols. In this study, we employed a publicly available structural and resting-state functional magnetic resonance imaging (fMRI) dataset to investigate the temporal effects of the optimal neuromodulation targets and parameters inferred from our customized neuromodulation protocol and examine the test-retest reliability over scanning time. 57 healthy young subjects were included in this study. Each subject underwent a repeated structural and resting state fMRI scan in two visits with an interval of 6 weeks between two scanning visits. Brain controllability analysis was performed to determine the optimal neuromodulation targets and optimal control analysis was further applied to calculate the optimal neuromodulation parameters for specific brain states transition. Intra-class correlation (ICC) measure was utilized to examine the test-retest reliability. Our results demonstrated that the optimal neuromodulation targets and parameters had excellent test-retest reliability (both ICCs > 0.80). The test-retest reliability of model fitting accuracies between the actual final state and the simulated final state also showed a good test-retest reliability (ICC > 0.65). Our results indicated the validity of our customized neuromodulation protocol to reliably identify the optimal neuromodulation targets and parameters between visits, which may be reliably extended to optimize the neuromodulation protocols to efficiently treat different neuropsychiatric disorders.

Thermal Characteristics of an Unsteady Hybrid Nano-Casson Fluid Passing Through a Stretching Thin-Film with Mass Transition

In current communication, the thin-film flow of Casson hybrid nanofluid consists of copper and alumina nanoparticles that dissolved in carboxymethyl cellulose (CMC) plus water over an unsteady stretching porous sheet is elucidated. Using suitable similarity variables, the resultant partial governing equations are turned into a set of nonlinear ordinary differential equations. The Keller box approach is then used to solve the transformed equations. The unknown thin-film thickness constant is determined by using the homotopy analysis approach. The thermal and velocity distributions, as well as the Nusselt number and skin friction of the fluid, are discussed for different values of relevant parameters such as thin-film thickness, nanoparticles volume fraction, and mass transition parameter. The distributions of temperature and velocity decrease when the thin-film thickness is increased. The velocity distribution is decreased by the Casson, nanoparticles volume fraction, and mass transition (injection) parameter. The temperature is enhanced by the nanoparticle's volume fraction and the Casson parameter, however, has an opposite tendency with the mass transition (injection) parameter. For the physical quantities, the skin friction has a negative function with all the parameters. The mass transition (injection) parameter increases the Nusselt number. The outcomes of the present study are useful for example in producing the smart contact lens that has been used in the biomedical field.

Analytical solution for natural convection of a heat-generating fluid in a vertical rectangular cavity with two pairs of heat source/sink

An analytical solution of the steady natural convective flow in a vertical rectangular cavity induced by a uniform volumetric heat generation is established in the case where two source/sink pairs are separately mounted on its vertical sidewalls. The developed analytical solution is based on the perturbation theory and the Fourier series expansion analysis. Primary efforts focus on the significant effect of the source/sink pairs arrangement on the fluid flow and heat transfer characteristics in the cavity. Therefore, three different configurations are considered, and the established theoretical formulas are validated using numerical simulations based on the finite volume method. Comparisons are made for various cavity aspect ratios A ranging from 0.2 to 2, heat source/sink amplitude r from 0 to 0.5, and the transition parameter α from 0 to 0.3. The Rayleigh number, chosen as the perturbation quantity, is fixed at Ra=103. Results clearly show a good agreement regarding streamlines, isotherms, velocity, and temperature profiles. It is observed that for low α values, the local heat transfer along the cavity active walls undergoes an oscillating behavior due to the truncation errors in the mathematical process of integration.

The cosmic web of X-ray active galactic nuclei seen through the eROSITA Final Equatorial Depth Survey (eFEDS)

Which galaxies in the general population turn into active galactic nuclei (AGNs) is a keystone of galaxy formation and evolution. Thanks to SRG/eROSITA’s contiguous 140 square degree pilot survey field, we constructed a large, complete, and unbiased soft X-ray flux-limited (FX > 6.5 × 10−15 erg s−1 cm−2) AGN sample at low redshift, 0.05 < z < 0.55. Two summary statistics, the clustering using spectra from SDSS-V and galaxy-galaxy lensing with imaging from HSC, are measured and interpreted with halo occupation distribution and abundance matching models. Both models successfully account for the observations. We obtain an exceptionally complete view of the AGN halo occupation distribution. The population of AGNs is broadly distributed among halos with a mean mass of 3.9−2.4+2.0 × 1012 M⊙. This corresponds to a large-scale halo bias of b(z = 0.34) = 0.99−0.10+0.08. The central occupation has a large transition parameter, σlog10(M) = 1.28 ± 0.2. The satellite occupation distribution is characterized by a shallow slope, αsat = 0.73 ± 0.38. We find that AGNs in satellites are rare, with fsat < 20%. Most soft X-ray-selected AGNs are hosted by central galaxies in their dark matter halo. A weak correlation between soft X-ray luminosity and large-scale halo bias is confirmed (3.3σ). We discuss the implications of environmental-dependent AGN triggering. This study paves the way toward fully charting, in the coming decade, the coevolution of X-ray AGNs, their host galaxies, and dark matter halos by combining eROSITA with SDSS-V, 4MOST, DESI, LSST, and Euclid data.

Improved plastic-damage cap model for shear behavior predictions of plain and reinforced concrete members

In this article, an improved continuous surface cap model (ICSC) with isotropic plastic-damage algorithms is proposed, namely to predict more accurately the shear behavior of both plain and reinforced concrete members. For this, a suitable yield surface is implemented and the critical shear-to-compression transition parameter in the ductile damage law is scrutinized and determined. Firstly, the mathematical framework of the plastic-damage cap model is summarized, namely the formulations in plasticity, the returning mapping algorithms of cutting plane and the isotropic damage law. Then, the proposed constitutive parameters in ICSC model are presented. The plastic-damage algorithms flowchart is presented and described, and the new proposed ICSC model is implemented in the software LS-DYNA. Next, the proposed ICSC model is validated against the original CSC model (MAT159 in LS-DYNA) and also against the previously improved CSC model with crack closure behavior developed by the authors. For this, several simulations using the three CSC models are performed and the results are compared with experimental results, which involve single concrete element under various loading conditions, plain concrete structure under direct shear load and simply supported reinforced concrete (RC) beams with or without stirrups under a center-point load. The results are presented and discussed. They show the superiority of the proposed ICSC model for the prediction of the ultimate concrete behavior at the material level, and a better prediction of the shear behavior for plain concrete and reinforced concrete beams.

Converting the sub-Jovian desert of exoplanets to a savanna with TESS, PLATO, and Ariel

ABSTRACT There is a lack of exoplanets with sizes similar to Neptune orbiting their host stars with periods ≲3 d – hence the name ‘sub-Jovian/Neptune desert’. Recently, several exoplanets have been confirmed to reside in the desert, transforming it into a ‘savanna’ with several ‘giraffe’ planets (such as LTT 9779 b and TOI-674 b). The most prominent scenarios put forward for the explanation of the formation of the desert are related to the stellar irradiation destroying the primary atmosphere of certain specific exoplanets. We aim to present three targets (LTT 9779 b, TOI-674 b, and WASP-156 b) that, when observed at wide wavelength ranges in infrared (IR), could prove the presence of these processes, and therefore improve the theories of planetary formation/evolution. We simulate and analyse realistic light curves of the selected exoplanets with PLATO/N-CAM and the three narrow-band filters of Ariel (VISPhot, FGS1, and FGS2) based on TESS observations of these targets. We improved the precision of the transit parameters of the three considered planets from the TESS data. We find that the combination of the three narrow-band filters of Ariel can yield an inner precision of ${\lesssim}1.1\ \hbox{per cent}$ for the planetary radii. Data from the three telescopes together will span decades, allowing the monitoring of changes in the planetary atmosphere through radius measurements. The three selected ‘giraffe’ planets can be golden targets for Ariel, whereby the loss of planetary mass due to stellar irradiation could be studied with high precision, multiwavelength (spectro-)photometry.

Reconstructing physical parameters from template gravitational wave spectra at LISA: first order phase transitions

A gravitational wave background from a first order phase transition in the early universe may be observable at millihertz gravitational wave (GW) detectors such as the Laser Interferometer Space Antenna (LISA). In this paper we introduce and test a method for investigating LISA's sensitivity to gravitational waves from a first order phase transition using parametrised templates as an approximation to a more complete physical model. The motivation for developing the method is to provide a less computationally intensive way to perform Markov Chain Monte Carlo (MCMC) inference on the thermodynamic parameters of a first order phase transition, or on generally computationally intensive models. Starting from a map between the physical parameters and the parameters of an empirical template, we first construct a prior on the empirical parameters that contains the necessary information about the physical parameters; we then use the inverse mapping to reconstruct approximate posteriors on the physical parameters from a fast MCMC on the empirical template. We test the method on a double broken power law approximation to spectra in the sound shell model. The reconstruction method substantially reduces the proposal evaluation time, and despite requiring some precomputing of the mapping, this method is still cost-effective overall. In two test cases, with signal-to-noise ∼ 40, the method recovers the physical parameters and the spectrum of the injected gravitational wave power spectrum to 95% confidence. In previous Fisher matrix analysis we found the phase boundary speed v w was expected to be the best constrained of the thermodynamic parameters. In this work, for an injected phase transition GW power spectrum with v w = 0.55, with a direct sample on the thermodynamic parameters we recover 0.630+0.17 -0.059 and for our reconstructed sample 0.646+0.098 -0.075.

The geometric albedo of the hot Jupiter HD 189733b measured with CHEOPS

Context. Measurements of the occultation of an exoplanet at visible wavelengths allow us to determine the reflective properties of a planetary atmosphere. The observed occultation depth can be translated into a geometric albedo. This in turn aids in characterising the structure and composition of an atmosphere by providing additional information on the wavelength-dependent reflective qualities of the aerosols in the atmosphere. Aims. Our aim is to provide a precise measurement of the geometric albedo of the gas giant HD 189733b by measuring the occultation depth in the broad optical bandpass of CHEOPS (350–1100 nm). Methods. We analysed 13 observations of the occultation of HD 189733b performed by CHEOPS utilising the Python package PyCHEOPS. The resulting occultation depth is then used to infer the geometric albedo accounting for the contribution of thermal emission from the planet. We also aid the analysis by refining the transit parameters combining observations made by the TESS and CHEOPS space telescopes. Results. We report the detection of an 24.7 ± 4.5 ppm occultation in the CHEOPS observations. This occultation depth corresponds to a geometric albedo of 0.076 ± 0.016. Our measurement is consistent with models assuming the atmosphere of the planet to be cloud-free at the scattering level and absorption in the CHEOPS band to be dominated by the resonant Na doublet. Taking into account previous optical-light occultation observations obtained with the Hubble Space Telescope, both measurements combined are consistent with a super-stellar Na elemental abundance in the dayside atmosphere of HD 189733b. We further constrain the planetary Bond albedo to between 0.013 and 0.42 at 3σ confidence. Conclusions. We find that the reflective properties of the HD 189733b dayside atmosphere are consistent with a cloud-free atmosphere having a super-stellar metal content. When compared to an analogous CHEOPS measurement for HD 209458b, our data hint at a slightly lower geometric albedo for HD 189733b (0.076 ± 0.016) than for HD 209458b (0.096 ± 0.016), or a higher atmospheric Na content in the same modelling framework. While our constraint on the Bond albedo is consistent with previously published values, we note that the higher-end values of ~0.4, as derived previously from infrared phase curves, would also require peculiarly high reflectance in the infrared, which again would make it more difficult to disentangle reflected and emitted light in the total observed flux, and therefore to correctly account for reflected light in the interpretation of those phase curves. Lower reported values for the Bond albedos are less affected by this ambiguity.

DSC Melting Profile of Cold-Pressed Hemp Seed Oil as an Authenticity Fingerprint Influenced by Scanning Rate

Among the variety of edible cold-pressed oils on the market, hemp seed oil is becoming increasingly popular among scientists and consumers due to its plethora of nutritional compounds. In this study, the goal was to examine the thermal characteristics of cold-pressed hemp seed oil pressed from seeds of the Henola cultivar procured by five different suppliers in two different seasons. This aim of this research was to establish how various scanning rates can affect the unique thermal profile of cold-pressed hemp seed oil in terms of an authenticity assessment. The melting transition was manifested by curves with four peaks for all hemp seed oils; however, they differed for each scanning rate in terms of the shape and peak intensity. Comparing the curves obtained at heating rates of 1 and 2 °C/min, noticeable differences were observed in the melting transition parameters between hemp seed oils, showing that small differences in fatty acid composition can cause changes in DSC profiles. In contrast, at a scanning rate 5 °C/min, the melting curves were similar for all hemp seed oils. It was also observed that for all the scanning rates, there was a strong negative correlation between the total content of polyunsaturated fatty acids (ƩPUFAs) and the peak temperature of the three peaks (Tm2, Tm3, and Tm4). The most abundant fatty acids were PUFAs, i.e., linoleic acid (C18:2), with contents ranging from 47 to 55%; and α-linolenic acid (C 18:3 n–3), with contents ranging from 17 to 25%. The application of linear discriminant analysis (LDA) enabled a discriminant model to be built based on the DSC data obtained for differentiation of oils pressed from fresh and stored seeds.

The effects of low-dose sorafenib on epithelial-mesenchymal transition and multidrug resistance markers in HepG2 cell line

Objectives: Sorafenib is an orally administered tyrosine kinase inhibitor in hepatocellular cancer. Low sorafenib concentrations are attained during pharmacotherapy due to pharmacokinetic profile and patient inadherence. Resistance to treatment is a limitation to improving survival. Underlying mechanisms include epithelial-mesenchymal transition. The aim of the study was to evaluate epithelial-mesenchymal transition and multidrug resistance-related parameters in HepG2 cells following low-dose and short-term sorafenib treatment. Methods: Epithelial-mesenchymal transition and multidrug resistance-related markers were examined by quantitative PCR, flow cytometry, and confocal laser scanning microscopy. Results: An increase in epithelial marker E-cadherin and downregulation of mesenchymal markers Vimentin and Snail1 were detected by gene expression analysis. While P-glycoprotein expression increased, multidrug resistance protein 1, and breast cancer resistance protein mRNA levels did not alter after sorafenib treatment. The accumulation of the ABC transporter substrate rhodamine 123 in the cells increased following the treatment, corresponding to a less efficient efflux of rhodamine 123 and a possible effect on other transporters and mechanisms. Conclusions: The results indicate a protective effect of sorafenib against epithelial-mesenchymal transition and upregulation in P-glycoprotein expression, which is, however, not sufficient to cause less intracellular rhodamine 123 accumulation. The effects of low-dose and short-term sorafenib on epithelial-mesenchymal transition and multidrug resistance-related markers might contribute to enlightening new treatment strategies in hepatocellular cancer.

Dynamical masses of two young transiting sub-Neptunes orbiting HD 63433

Context.Although the number of exoplanets reported in the literature exceeds 5000 so far, only a few dozen of them are young planets (≤900 Myr). However, a complete characterization of these young planets is key to understanding the current properties of the entire population. Hence, it is necessary to constrain the planetary formation processes and the timescales of dynamical evolution by measuring the masses of exoplanets transiting young stars.Aims.We characterize and measure the masses of two transiting planets orbiting the 400 Myr old solar-type star HD 63433, which is a member of the Ursa Major moving group.Methods.We analysed precise photometric light curves of five sectors of the TESS mission with a baseline of ~750 days and obtained ~150 precise radial velocity measurements with the visible and infrared arms of the CARMENES instrument at the Calar Alto 3.5 m telescope in two different campaigns of ~500 days. We performed a combined photometric and spectroscopic analysis to retrieve the planetary properties of two young planets. The strong stellar activity signal was modelled by Gaussian regression processes.Results.We have updated the transit parameters of HD 63433 b and c and obtained planet radii ofRpb= 2.140 ± 0.087R⊕andRpc= 2.692 ± 0.108R⊕. Our analysis allowed us to determine the dynamical mass of the outer planet with a 4σsignificance (Mpc= 15.54 ± 3.86M⊕) and set an upper limit on the mass of the inner planet at 3σ (Mpb< 21.76M⊕). According to theoretical models, both planets are expected to be sub-Neptunes, whose interiors mostly consist of silicates and water with no dominant composition of iron, and whose gas envelopes are lower than 2% in the case of HD 63433 c. The envelope is unconstrained in HD 63433 b.

Control of electron beam current, charge, and energy spread using density downramp injection in laser wakefield accelerators

Density downramp injection has been demonstrated to be an elegant and efficient approach for generating high-quality electron beams in laser wakefield accelerators. Recent studies have demonstrated the possibilities of generating electron beams with charges ranging from tens to hundreds of picocoulombs while maintaining good beam quality. However, the plasma and laser parameters in these studies have been limited to specific ranges or attention has been focused on separate physical processes such as beam loading, which affects the uniformity of the accelerating field and thus the energy spread of the trapped electrons, the repulsive force from the rear spike of the bubble, which reduces the transverse momentum p⊥ of the trapped electrons and results in small beam emittance, and the laser evolution when traveling in the plasma. In this work, we present a comprehensive numerical study of downramp injection in the laser wakefield, and we demonstrate that the current profile of the injected electron beam is directly correlated with the density transition parameters, which further affects the beam charge and energy evolution. By fine-tuning the plasma density parameters, electron beams with high charge (up to several hundreds of picocoulombs) and low energy spread (around 1% FWHM) can be obtained. All these results are supported by large-scale quasi-three-dimensional particle-in-cell simulations. We anticipate that the electron beams with tunable beam properties generated using this approach will be suitable for a wide range of applications.

Assessing overdiagnosis of fecal immunological test screening for colorectal cancer with a digital twin approach

Evaluating the magnitude of overdiagnosis associated with stool-based service screening for colorectal cancer (CRC) beyond a randomized controlled trial is often intractable and understudied. We aim to estimate the proportion of overdiagnosis in population-based service screening programs for CRC with the fecal immunochemical test (FIT). The natural process of overdiagnosis-embedded disease was first built up to learn transition parameters that quantify the pathway of non-progressive and progressive screen-detected cases calibrated with sensitivity, while also taking competing mortality into account. The Markov algorithms were then developed for estimating these transition parameters based on Taiwan FIT service CRC screening data on 5,417,699 residents aged 50–69 years from 2004 to 2014. Following the digital twin design with the parallel universe structure for emulating the randomized controlled trial, the screened twin, mirroring the control group without screening, was virtually recreated by the application of the above-mentioned trained parameters to predict CRC cases containing overdiagnosis. The ratio of the predicted CRCs derived from the screened twin to the observed CRCs of the control group minus 1 was imputed to measure the extent of overdiagnosis. The extent of overdiagnosis for invasive CRCs resulting from FIT screening is 4.16% (95% CI: 2.61–5.78%). The corresponding figure is increased to 9.90% (95% CI: 8.41–11.42%) for including high grade dysplasia (HGD) and further inflated to 15.83% (95% CI: 15.23–16.46%) when the removal adenoma is considered. The modest proportion of overdiagnosis modelled by the digital twin method, dispensing with the randomized controlled trial design, suggests the harm done to population-based FIT service screening is negligible.

Suppression of wetting transition on evaporative fakir droplets by using slippery superhydrophobic surfaces with low depinning force

This study experimentally investigated the evaporation and wetting transition behavior of fakir droplets on five different microstructured surfaces. Diamond-like carbon was introduced as the substrate, and the influence of varying the width, height, and pitch of the micropillars was assessed. The experimental results showed that the interfacial properties of the surfaces change the evaporation behavior and the starting point of the wetting transition. An important result of this study is the demonstration of a slippery superhydrophobic surface with low depinning force that suppresses the transition from the Cassie–Baxter state to the Wenzel state for microdroplets less than 0.37 mm in diameter, without employing large pillar height or multiscale roughness. By selecting an appropriate pillar pitch and employing tapered micropillars with small pillar widths, the solid–liquid contact at the three-phase contact line was reduced and low depinning forces were obtained. The underlying mechanism by which slippery superhydrophobic surfaces suppress wetting transitions is also discussed. The accuracy of the theoretical models for predicting the critical transition parameters was assessed, and a numerical model was developed in the surface evolver to compute the penetration of the droplet bottom meniscus within the micropillars.

Evaluation of effects of short and long-term thermo-oxidative aging on chemo-rheological and mechanical properties of asphalt concretes

The effects of short and long-term thermo-oxidative aging on stripping resistance, rut depth, stiffness modulus, fracture and fatigue resistances of asphalt concretes have been assessed. A modified RILEM thermo-oxidative aging procedure on loose asphalt mixtures has been used to evaluate the gradual evolution of these properties with the aging duration. Two short-term aging durations (4 and 8 hours at 135C) and three long-term thermo-oxidative aging durations (3, 6 and 9 days at 85C) and a reference mixture (0 day aging) have been considered to this end. The impact of long-term thermo-oxidative aging on the chemo-rheological properties of recovered asphalt binders have been investigated. At the binder scale, the results show an increase in the Fraass temperature, the softening point, the shear modulus , the aging index (AI= + ) and a decrease in the penetration grade with the aging duration. Some correlations between the viscoelastic transition parameters (, and ) of the recovered asphalt binders and the aging index have been established. At the mixture scale, the results show that the stiffness modulus () increases with the aging duration, while the index of fracture resistance (IFR), the stripping resistance (), the rut depth (P) and the fatigue deformation () decrease with the aging duration. Finally, some correlations between the aging index and the rheological and the mechanical properties of binders and concretes (, , P, IFR, ) have been proposed.

Testing the phase transition parameters inside neutron stars with the production of protons and lambdas in relativistic heavy-ion collisions

We demonstrate the consistency of the quark deconfinement phase transition parameters in the beta-stable neutron star matter and in the nearly symmetric nuclear matter formed in heavy-ion collisions (HICs). We investigate the proton and $\mathrm{\ensuremath{\Lambda}}$ flow in $\mathrm{Au}+\mathrm{Au}$ collisions at 3 and $4.5\text{ }\text{ }\mathrm{GeV}/\mathrm{nucleon}$ incident beam energies with the pure hadron cascade version of a multiphase transport model. The phase transition in HICs and neutron stars is described based on a class of hybrid equations of state from the quark mean-field model for the hadronic phase and a constant-speed-of-sound parametrization for the high-density quark phase. The measurements of the anisotropic proton flow at $3\text{ }\text{ }\mathrm{GeV}/\mathrm{nucleon}$ by the STAR Collaboration favor a relatively low phase transition density lower than $\ensuremath{\sim}2.5$ times saturation density indicated by the gravitational wave and electromagnetic observations of neutron stars. And the proton flow data at the higher energy of $4.5\text{ }\text{ }\mathrm{GeV}/\mathrm{nucleon}$ can be used to effectively constrain the softness of high-density quark matter equations of state. Finally, compared to the proton flow, the $\mathrm{\ensuremath{\Lambda}}$ flow is found to be less sensitive and not constraining to the equations of state.

Study of phase behavior of epoxy asphalt binders using differential scanning calorimetry

Glass transition parameters can be used to study the miscibility, or lack of it, in polymer-modified asphalt binders. In this study, the contribution of thermodynamics of mixing to glass transition was quantitatively assessed in a differential scanning calorimeter for four asphalt binders partially and fully replaced by an epoxy system. The values of heat capacity (Cp) and, subsequently the glass transition temperature (Tg) of all binders were determined to quantify the miscibility based on the entropic changes. Emphasis was also given to examining the enthalpy of mixing as a function of epoxy system composition during curing to ensure that these binders were completely crosslinked for further analyses. In all cases, the positive deviations of the measured Tg of epoxy-modified asphalt binders (Tg,mix) obtained from the ideal mixing rule led to negative values of the entropy of mixing (ΔSmixc), dictating the presence of internal repulsive forces between the asphalt and epoxy components. Softer binders were associated with binders of low deviations of Tg,mix values from the ideal mixing rule. Lastly, the partial replacement of asphalt binders by the epoxy system increased the Tg and decreased the amount of ΔSmixc, and such performance imposes the formation of immiscible products.

Allosteric and substrate site effects of relevant amino acids on structural stability and flexibility of glutamate dehydrogenase-1 (GDH-1).

Mammalian GDH-1, which converts glutamate to alpha-ketoglutarate and ammonia while reducing NAD(P), is constitutively expressed in virtually all cells of the body. The extensive literature on GDH-1 suggests that functionally relevant GDH-1 structures may be distributed over a conformational flexibility landscape: polyhexamer, hexamer, trimer, monomer, monomer (unfolded), monomer (misfolded), polymer (disassembled). We have used both intrinsic (tryptophan) and extrinsic (ANS) fluorescent probes to study the dependence of the reversible hexamer to trimer dissociation on the concentrations of the denaturing agents urea and guanidine hydrochloride (GdnHCl). Dissociation at each denaturant concentration increases with increase in concentration and/or temperature, and these dependencies are shown to be affected by amino acids which bind to allosteric and/or substrate binding sites. Dissociation of the hexamer is accompanied by a large increase in the fluorescence of ANS due to binding to increase in exposed hydrophobic microdomains on the protein. In contrast, tryptophan fluorescence decreases due to increased exposure of tryptopan in the protein to the aqueous environment. Measurement were made of the influence of several known substrates and allosteric modifiers (i.e. a selection physiologically relevant monocarboxylic amino acids) on the GDH-1 hexamer to trimer transition. The observed effect of adding each amino acid is consistent with independent measurements of its binding affinity. From the temperature dependence of the fluorescence intensity changes for ANS we obtained activation parameters for the hexamer-trimer transitions. Our data are consistent with the hexamer/trimer transition in GDH-1 having significant regulatory function in vivo, perhaps contribution to/complementing allosteric regulation of the enzyme activity.