Influence of Carboxymethyl Cellulose as a Thickening Agent for Glauber's Salt-Based Low Temperature PCM.

This work is focused on a novel, promising low temperature phase change material (PCM), based on the eutectic Glauber's salt composition. To allow phase transition within the refrigeration range of temperatures of +5 °C to +12 °C, combined with a high repeatability of melting-freezing processes, and minimized subcooling, the application of three variants of sodium carboxymethyl cellulose (Na-CMC) with distinct molecular weights (700,000, 250,000, and 90,000) is considered. The primary objective is to optimize the stabilization of this eutectic PCM formulation, while maintaining the desired enthalpy level. Preparation methods are refined to ensure repeatability in mixing components, thereby optimizing performance and stability. Additionally, the influence of Na-CMC molecular weight on stabilization is examined through differential scanning calorimetry (DSC), T-history, and rheology tests. The PCM formulation of interest builds upon prior research in which borax, ammonium chloride, and potassium chloride were used as additives to sodium sulfate decahydrate (Glauber's salt), prioritizing environmentally responsible materials. The results reveal that CMC with molecular weights of 250 kg/mol and 90 kg/mol effectively stabilize the PCM without phase separation issues, slowing crystallization kinetics. Conversely, CMC of 700 kg/mol proved ineffective due to the disruption of gel formation at its low gel point, hindering higher concentrations. Calculations of ionic concentration indicate higher Na ion content in PCM stabilized with 90 kg/mol CMC, suggesting increased ionic interactions and gel strength. A tradeoff is discovered between the faster crystallization in lower molecular weight CMC and the higher concentration required, which increases the amount of inert material that does not participate in the phase transition. After thermal cycling, the best formulation had a latent heat of 130 J/g with no supercooling, demonstrating excellent performance. This work advances PCM's reliability as a thermal energy storage solution for diverse applications and highlights the complex relationship between Na-CMC molecular weight and PCM stabilization.

A new approach for deducing rms proton radii from charge-changing reactions of neutron-rich nuclei and the reaction-target dependence.

We report the charge-changing cross sections (σcc) of 24 p-shell nuclides on both hydrogen and carbon at about 900A MeV, of which 8,9Li, 10-12Be, 10,14,15B, 14,15,17-22N and 16O on hydrogen and 8,9Li on carbon are for the first time. Benefiting from the data set, we found a new and robust relationship between the scaling factor of the Glauber model calculations and the separation energies of the nuclei of interest on both targets. This allows us to deduce proton radii (Rp) for the first time from the cross sections on hydrogen. Nearly identical Rp values are deduced from both target data for the neutron-rich carbon isotopes; however, the Rp from the hydrogen target is systematically smaller in the neutron-rich nitrogen isotopes. This calls for further experimental and theoretical investigations.

Opinion Models, Election Data, and Political Theory.

A unifying setup for opinion models originating in statistical physics and stochastic opinion dynamics are developed and used to analyze election data. The results are interpreted in the light of political theory. We investigate the connection between Potts (Curie-Weiss) models and stochastic opinion models in the view of the Boltzmann distribution and stochastic Glauber dynamics. We particularly find that the q-voter model can be considered as a natural extension of the Zealot model, which is adapted by Lagrangian parameters. We also discuss weak and strong effects (also called extensive and nonextensive) continuum limits for the models. The results are used to compare the Curie-Weiss model, two q-voter models (weak and strong effects), and a reinforcement model (weak effects) in explaining electoral outcomes in four western democracies (United States, Great Britain, France, and Germany). We find that particularly the weak effects models are able to fit the data (Kolmogorov-Smirnov test) where the weak effects reinforcement model performs best (AIC). Additionally, we show how the institutional structure shapes the process of opinion formation. By focusing on the dynamics of opinion formation preceding the act of voting, the models discussed in this paper give insights both into the empirical explanation of elections as such, as well as important aspects of the theory of democracy. Therefore, this paper shows the usefulness of an interdisciplinary approach in studying real world political outcomes by using mathematical models.

Study of Total, Absorption, and 3He and 3H Production Cross Sections in 4He-proton Collisions.

Light ion breakup cross sections are important for studies of cosmic ray interactions in the inter-stellar medium or radiation protection considerations of energy deposition in shielding and tissues. Abrasion cross sections for heavy ion reactions have been modeled using the Glauber model in the large mass limit or Eikonal form of the optical potential model. Here we formulate an abrasion model for 4He fragmentation on protons using the Glauber model avoiding the large mass limit and include a model for final state interactions. Calculations of energy dependent total, absorption, elastic and breakup cross sections for 4He into 3He or 3H with proton targets are shown to be in good agreement with experiments for energies from 100 to 100,000 MeV/u. The Glauber model for light nuclei with and without a large mass limit approximation is shown to be in fair agreement above 300 MeV/u, however important differences occur at lower energies.

Phase-Changing Glauber Salt Solution for Medical Applications in the 28-32 °C Interval.

(1) Background: The field of medicine requires simple cooling materials. However, there is little knowledge documented about phase change materials (PCM) covering the range of 28 to 40 degrees Celsius, as needed for medical use. Induced mild hypothermia, started within 6 h after birth, is an emerging therapy for reducing death and severe disabilities in asphyxiated infants. Currently, this hypothermia is accomplished with equipment that needs a power source and a liquid supply. Neonatal cooling is more frequent in low-resource settings, where ~1 million deaths are caused by birth-asphyxia. (2) Methods: A simple and safe cooling method suitable for medical application is needed for the 28 to 37.5 °C window. (3) Results: Using empirical experiments in which the ingredients in Glauber salt were changed, we studied the effects of temperature on material in the indicated temperature range. The examination, in a controlled manner, of different mixtures of NaCl, Na2SO4 and water resulted in a better understanding of how the different mixtures act and how to compose salt solutions that can satisfy clinical cooling specifications. (4) Conclusions: Our Glauber salt solution is a clinically suited PCM in the temperature interval needed for the cooling of infants suffering from asphyxia.

Synthesis of sodium silicate using industrial by-products glauber's salt and microsilica: Effective reuse of the waste.

Large amounts of by-products, including glauber's salt (GS) and microsilica (MS), are accumulated from chlor-alkali industry and ferrosilicon industry development, which not only wastes precious resources, but also causes serious environmental problems. In order to recycle and reuse these industrial by-products, solid sodium silicate was synthesized using GS and MS as the main raw materials, and semi-coke (SC) as the reducing agent. The effects of melting parameters including GS/SC and MS/GS molar ratio, heating rate, temperature, reaction time, and SC particle size on the conversion efficiency and modulus of solid sodium silicate were investigated and optimized. Under optimal conditions, the maximum conversion efficiency of 94.91% was obtained with modulus of 2.5. Characterization analysis of the products indicated that the amorphous silicate sodium was successfully synthesized. Moreover, the reaction mechanism was investigated, which focused on the thermal behavior and phase transformation using thermo-gravimetric and differential scanning calorimetric (TG-DSC) and in-situ X-ray diffraction. Additionally, the causes and suppression measures of "glauber's salt water" (GSW) during the experiment were summarized. This work not only creates resource utilization of GS and MS, but also provides the foundation for the synthesis of sodium silicate with GS.

Nonequilibrium magnetic properties of the Sr2FeMoO6type double perovskite structure.

The Glauber-type stochastic dynamic interpreted by the mean-field theory has been applied to investigate the dynamic magnetic properties of the Sr2FeMoO6type double perovskite structure under the time varying magnetic field. First, we used the Glauber dynamics to obtain the dynamic mean-field equations. The time varying average Fe and Mo magnetizations are examined to find the phase region of the system. The dynamic Fe and Mo magnetizations, hysteresis loop areas and correlations are calculated depending on the temperature in order to determine the nature of the first and second order phase transitions, as well as to get the dynamic transition points for different ratio of the system parameters. The dynamic phase diagrams (DPDs) are constructed in the plane of reduced temperature and external magnetic field amplitude (T,h). The DPDs contain paramagnetic (p), ferromagnetic (f), ferrimagnetic-1 (i1), ferrimagnetic-2 (i2) phases and six mixed regions, (f + p), (f + i1), (f + i2), (i1+ p), (i2+ p) and (i1+ i2). The DPDs also exhibit dynamic tricritical points and reentrant phenomena, which strongly depend on interaction parameters.

On Compressed Sensing of Binary Signals for the Unsourced Random Access Channel.

Motivated by applications in unsourced random access, this paper develops a novel scheme for the problem of compressed sensing of binary signals. In this problem, the goal is to design a sensing matrix A and a recovery algorithm, such that the sparse binary vector x can be recovered reliably from the measurements y=Ax+σz, where z is additive white Gaussian noise. We propose to design A as a parity check matrix of a low-density parity-check code (LDPC) and to recover x from the measurements y using a Markov chain Monte Carlo algorithm, which runs relatively fast due to the sparse structure of A. The performance of our scheme is comparable to state-of-the-art schemes, which use dense sensing matrices, while enjoying the advantages of using a sparse sensing matrix.

How the all-atom simulation and the ising-based theory reconcilewith each other on the helix-coil transition.

In this report, we addressed a somewhat basic question about how the twoextreme models, the all-atom model and the Ising-based model, can beconsistent with each other regarding the polypeptide helix-coil transition.Comparisons of several physical properties were made between the resultsof the all-atom simulations and those of the Ising-based theories. Fromthe equilibrium point of view, the two models were found to exhibit aqualitatively similar trend, which is significant considering the extremedifference in precision between the two models. On the other hand, fromthe kinetic viewpoint, there appeared a difference in relaxation behaviorbetween the two models; i.e., so-called stretched exponential relaxationwas observed in the all-atom simulation whereas the kinetic Ising modelshowed simple exponential relaxation. A plausible source of the observeddifference is briefly discussed.