A phase transition modulates the protective function of a tardigrade disordered protein during desiccation

This paper introduces a technique for assessing the reliability of protection and control systems using reliability models and event tree analysis. This technique allows a quantitative reliability assessment to be made, which can then be used to determine the effect of integrating different protection and control functions into a single unit. The term reliability when applied to protection system failure can be considered in terms of dependability and security. Dependability is defined as the probability that the protection operates satisfactorily when required, i.e. it does not fail to trip. Security is defined as the probability that the protection does not operate when not required to do so, i.e. it does not produce unwanted trips. Dependability results are given in this paper for feeder protection schemes based on differential protection, distance protection and combined differential and distance protection. The effect on the dependability of these schemes of including a separate and an integral intertrip unit is also considered. The former is housed in its own hardware, and the latter is integrated into the differential protection. Both intertrip units can be activated by either protection.

Introduction. An important factor determining the effectiveness of protective structures in urban construction projects is the ability of their enclosing elements to maintain their protective functions under combat conditions, block the impact of damaging factors caused by air, missile, and artillery strikes, and protect people from debris and fragments of building structures. A pressing issue today, in the context of a full-scale invasion by an aggressor country, is the protection of critical infrastructure, particularly energy facilities and energy communications. To provide such protection, specially equipped protective structures are used, primarily constructed from reinforced concrete monolithic enclosing elements. Research Objective. To justify a general computational and theoretical approach to methods for calculating the protective capacity of modular shelters in accordance with the standards in force in Ukraine, specifically DBN V.2.2-5:2023 “Civil Defence Structures. Buildings and Structures,” under the impact of an explosive shock wave. Research Methods. The analysis of structural destruction was performed with consideration of relevant plasticity and strength theories. Modern computational technologies, utilizing advanced software and numerical algorithms, were employed for the calculations. Computational procedures were based on the explicit integration method for dynamic equations over time, the finite element method, and the description of contact interactions using the penalty function method. Mathematical models of materials under high-speed deformation were applied, accounting for their nonlinear properties and failure criteria in accordance with the relevant strength theories. Research Results. Patterns of correlation between explosion parameters and the stability of structural elements, in particular walls made of concrete lightweight blocks, have been established, which is important for assessing their residual protective capacity. The use of modern numerical modeling methods—including the finite element method, explicit integration of dynamic equations, contact interaction models, and nonlinear material models—enabled insight into the mechanisms of destruction and indicators of loss of integrity of protective structures as a result of explosions. This analysis included the most critical combination of explosion parameters, with a TNT equivalent charge of m (TNT) = 718.2 kg. The mechanisms of destruction or integrity loss in shelter structures were investigated, and their relationship to the performance of protective functions under an explosion with a TNT equivalent charge of m (TNT) = 30 kg and a minimum distance from the epicenter to the shelter surface of L = 0.5 m. Distributions of plate deformations were obtained for blast wave pressure applied to the shelter structure from the side, the end (closer to the door), and above the upper horizontal surface in the middle.

The interaction of α-tocopherol with phosphatidylserine vesicles and calcium

The role of the phospholipid phase transition in the regulation of glucagon binding to lecithin

Binary mixtures of two phosphatidylcholines of different chain lengths are simulated in the bilayer state. We find a phase transition between a liquid state and a gel state at all concentrations. This phase transition is characterized by the area per lipid headgroup, the order parameter, and a change in dynamics. At concentrations with a majority of the longer lipid, we find phase separation into a gel and a liquid state in a small temperature window. This leads to a strong dynamic heterogeneity. Experimental phase transition temperatures are reproduced semiquantitatively. We see a clear shift in the phase transition to higher temperatures with increasing concentration of the longer lipid.

Investigation of thermodynamic state evolution, phase transition and mixing of the hydrocarbon droplet in convective supercritical environments

This article presents the development, implementation, and testing of a digital differential protection for three-phase (3φ) solid-state transformers (SSTs). The developed digital differential protection is designed to implement the ANSI 87 T protection function. The differential currents used by the developed protection are created by the dq0 components of the currents flowing in the high and low voltage sides of a 3φ SST. Internal faults are detected and identified using the energy contents of high-frequency subbands present in the dq0 differential currents. The desired high-frequency subbands are extracted using the phaselet transform that processes signals without sensitivity to nonstationary changes in their frequency and/or phases. Energy contents in the extracted high-frequency subbands allow accurate, fast, and reliable detection and identification of faults in any part of a 3φ SST. The proposed digital differential protection is implemented for performance testing using a laboratory 25-kVA 3φ SST. Performance results demonstrate accurate, fast, and reliable response to different fault and nonfault events. Furthermore, responses of the developed differential protection are found to be consistent regardless of the fault type, fault location, and/or loading level.

This paper aims to present a methodology for performance evaluation of power transformers differential protection using the software ATP. In order to do so, the MODELS language is used to model a numerical relay that implements phase, negative sequence and restricted earth fault differential protective functions. The performance evaluation of the power transformer protection was done using a power system model whose parameters were obtained from real data. The results reveal the performance of the implemented protective functions facing to a wide variety of operating situations to which they may be subjected to. Accordingly, one can point out advantages of this kind of modeling, which leads to the appropriate choice and better understanding of power transformers differential protection settings.

Stimuli-responsive metal complexes are extensively studied due to their promising properties for various practical applications. In many cases, stimuli-induced response is provoked by phase transitions, which completely modify electronic properties of chromophoric center to give substantial modification of the phase emissive properties. However, complexity of the systems hinders theoretical calculations, which could be used to interpret the emission response, even at qualitative level. In this study, we apply a joint experimental and theoretical approach to model the luminescence switching of a vapochromic Au–Cu organometallic supramolecular complex in solution, amorphous, and crystal state. We have investigated luminescence spectra and emission anisotropy of the complex in solution, polymer gel, amorphous, and crystal states. The excitation and emission energies of the complex in vacuum and crystal state have been calculated using QM and QM/MM approaches. The results show that (1) the red shift of emission of the complex in solution is caused by the conformational relaxation in the T1 state and (2) the blue shift of crystalline state emission originates from the interactions of the complex with the crystal environment. The model elaborated to describe the phenomena observed may provide a practical way to analyze stimuli-induced luminescence switching in analogous systems.

The interaction of ubiquinone-10 and ubiquinol-10 with phospholipid bilayers. A study using differential scanning calorimetry and turbidity measurements

Freezing is commonly encountered during the processing and storage of biomacromolecule products. Therefore, understanding the phase and state transitions in pharmaceutical frozen solutions is crucial for the rational development of biopharmaceuticals. Solid-state nuclear magnetic resonance spectroscopy (ssNMR) was used to analyze solutions containing sodium phosphate buffer, histidine, and trehalose. Upon freezing, crystallization of disodium phosphate hydrogen dodecahydrate (Na2HPO4·12H2O, DPDH) and histidine was identified using 31P and 13C ssNMR, respectively, and confirmed by synchrotron X-ray diffractometry (SXRD). Using histidine as a molecular probe and based on the chemical shifts of atoms of interest, the pH of the freeze concentrate was measured. The unfrozen water content in freeze concentrates was quantified by 1H single pulse experiments. 13C-insensitive nuclei enhancement by polarization transfer (INEPT) and cross-polarization (CP) experiments were used as orthogonal tools to characterize the solutes in a "mobile" and a more "solid-like" state in the freeze-concentrated solutions, respectively. The above analyses were applied to a commercial monoclonal antibody (mAb) formulation of dupilumab. This work further establishes ssNMR spectroscopy as a highly capable biophysical tool to investigate the attributes of biopharmaceuticals and thereby provide insights into process optimization and formulation development.

Decision letter for "Supramolecular Hydrogels Derived from 2:1-[α/aza]-Pseudopeptides: Design, Structural Analysis and Self-Assembly in Solution, Solid, and Gel States"

Coarse-Grained Strategy for Modeling Protein Stability in Concentrated Solutions. II: Phase Behavior

Naphthalimide–pyridoxal conjugated gelator1has been designed and synthesized. Compound1which forms stable greenish yellow colored gel in DMSO : H2O (8 : 1 v/v), shows selective sensing of F−in solution, gel and solid states under different conditions.

A new glycine-based reversible phase transition compound diglycine methanesulfonate (1) has been successfully synthesized. Differential scanning calorimetry (DSC) measurements of 1 showed a pair of broad peaks around 134 K (T(c)=phase transition temperature) with a slight thermal hysteresis during the heating/cooling cycle, thereby indicating that this compound undergoes a reversible second-order phase transition. Dielectric measurements further confirmed the phase transition and revealed a switchable response to the ambient temperature change for the dielectric constants of 1, namely, the dielectric constants have a distinctive step-like anomaly switching between a high dielectric state in the room temperature phase (RTP) and a low state in the low temperature phase (LTP). Variable-temperature single-crystal X-ray diffraction analyses show that 1 undergoes an atypical transition from the space group P2₁/m in the RTP to P2₁/c in the LTP. The origin of the switchable dielectric phase transition is ascribed to the movement of the moieties in 1 from the equilibrium position, and this stems from the twisting of the molecules in the compound. We believe that these findings will be useful in exploring switchable dielectric phase transition materials.