Static structure and dynamics of the liquid Li-Na and Li-Mg alloys

Concentration dependence of the structure of liquid Li-Na and Li-Mg alloys

We present theoretical calculations for the static structure and ordering properties of the Na - K liquid alloy. Our theoretical approach is based on the neutral pseudoatom method for deriving the interatomic pair potentials, and on the modified-hypernetted-chain theory of liquids for obtaining the liquid structure, leading to a whole combination that is free of adjustable parameters. The results obtained predict a weak phase-separating tendency, in good agreement with the available experimental data.

Static and dynamic properties of liquid Zn, Cd and Hg divalent metals: An orbital free ab initio molecular dynamics study

In this paper, designs of slotted propeller blade were discussed numerically, in terms of aerodynamic performance and static structural analysis. Baseline APC Slow Flyer 10’ x 7’ small scale propeller blade was modified by including slots along the propeller blade. Numerical analysis has been done to determine the influence of slots angle towards thrust coefficient, power coefficient and efficiency. Simulations were performed by using ANSYS Fluent implementing k-ω turbulence model and Multiple Reference Frame to incorporate rotational speed of the propeller. The analyses were conducted at a fixed rotational speed, with variance of advance ratio. Initial slotted design is set at 180 degree and the angles were changed with 10-degree interval, ranging from 180 degree to 90 degree. The results were compared with available experimental data. For the slotted design, the result shows that inducing slots do not always lead to improvement in propeller blade performance. Improvement in thrust coefficient with the range of 0.267% to 2.71% can be seen for low advance ratio for most of slot angles. However, a significant increase in power coefficient can be observed which reduces the overall efficiency of the propeller blade. For stress and deformation, ANSYS Mechanical Static Structure was used to determine maximum Von-Mises stress, maximum Von-Mises strain, and total deformation. The analyses were conducted by using 60% long strand fiber glass reinforced nylon 6 Natural. The blade is more suitable to operate at higher velocity. At lower operational velocity, the blade tends to experience material failure as the stress exceeds stress at break.

In a metallic glass (MG), the propensity for atomic rearrangements varies spatially from location to location in the amorphous solid, making the prediction of their likelihood a major challenge. One can attack this problem from the "structure controls properties" standpoint. But all the current structure-centric parameters are mostly based on local atomic packing information limited to short-range order, hence falling short in reliably forecasting how the local region would respond to external stimuli (e.g., temperature and/or stress). Alternatively, one can use indicators informed by physical properties to bridge the static structure on the one hand, and the response of the local configuration on the other. A sub-group of such physics-informed quantities consists of atomic vibration parameters, which will be singled out as the focus of this article. Here we use the Cu64Zr36 alloy to systematically demonstrate the following two points, all using a single model MG. First, we show in a comprehensive manner the interrelation among common vibrational parameters characterizing the atomic vibrational amplitude and frequency, including the atomic mean square displacement, flexibility volume, participation fraction in the low-frequency vibrational modes and boson peak intensity. Second, we demonstrate that these vibrational parameters fare much better than purely static structural parameters based on local geometrical packing in providing correlation with the propensity for local configurational transitions. These vibrational parameters also share a correlation length similar to that in structural rearrangements induced by external stimuli. This success, however, also poses a challenge, as it remains to be elucidated as to why short-time dynamical (vibrational) behavior at the bottom of the energy basin can be exploited to project the height of the energy barrier for cross-basin activities and in turn the propensity for locally collective atomic rearrangements.

The TH−PH Hugoniot curves of compressional shocks in 2D Yukawa systems are derived from the combination of the Rankine–Hugoniot relation around the shock front and the universal relationship for the temperature in the postshock region. From the equation of state of 2D Yukawa liquids, the equilibrium melting curve for 2D Yukawa systems is derived using the two variables of the temperature T and the pressure P. It is found that the obtained TH−PH Hugoniot curves are intercepted by the equilibrium melting curve, indicating the existence of shock-induced phase transition at these crossing points. To confirm this prediction, molecular dynamical simulations of 2D Yukawa systems of κ=0.75 for the conditions around the crossing point are performed. In the postshock region, the calculated various diagnostics of static structural measures, like the Voronoi diagram, the defect ratio, the probability distribution of the shape factors ξ, the pair correlation function g(r), and the static structure factor S(q), suggest that, for our studied system, the shock-induced melting happens when the compressional speed of the boundary is 0.212a0ωpd<vleft<0.283a0ωpd, the same as the prediction from the crossing point.

• A static structural model captures finite-temperature dynamics in CsPbI₃. • Band alignment at CsPbI₃/TiO₂ interfaces depends strongly on surface termination. • PbI₂-terminated CsPbI₃ enables efficient electron transport into TiO₂. • CsI termination suppresses electron injection across the interface. • Findings provide design rules for selective charge transport in perovskite solar cells. Accurate descriptions of the electronic structure of halide perovskites at finite temperatures require structural models that capture the dynamical tilting of BX 6 octahedra. Here, we demonstrate that a single static structure—constructed by combining the low-temperature γ-phase geometry with the cubic lattice of the α-phase—reproduces results obtained from time-averaged trajectories. Using this approach, we investigate how free surfaces and interfaces modify the electronic structure of lead-halide perovskites. Focusing on CsPbI 3 as a model halide perovskite interfaced with the prototypical electron transport layer TiO 2 , we make quantitative predictions of band offsets and band bending for the two possible CsPbI 3 (001) surface terminations, PbI 2 and CsI. Our results reveal that TiO 2 acts as an efficient electron transport layer only in the case of PbI 2 termination, highlighting the termination-dependent selectivity of charge transport at halide perovskite/TiO 2 interfaces.

Recently it has been revealed that when approaching the glass-transition temperature, T(g), the dynamics of a liquid not only drastically slows down, but also becomes progressively more heterogeneous. From our simulations and experiments of six different glass-forming liquids, we find that the heterogeneous dynamics is a result of critical-like fluctuations of static structural order, contrary to a common belief that it is purely of dynamic origin. The static correlation length and susceptibility of a structural order parameter show Ising-like power-law divergence towards the ideal glass-transition point. However, this structural ordering accompanies little density change, which explains why it has not been detected by the static structure factor so far. Our results suggest a far more direct link than thought before between glass transition and critical phenomena. Indeed, the glass transition may be a new type of critical phenomenon where a structural order parameter is directly linked to slowness.

In this study, a static structural tool in ANSYS software was utilized in order to carry out a numerical evaluation of the fatigue behavior of titanium alloy Ti-6Al-2Sn-4Zr-2Mo when subjected to dynamic loads. A static structure was utilized in the process of performing the analysis and meshing it using the Ansys program. A load of 3.15 (KN) has been assumed to be applied to the plate, and it is applied in the opposite direction of the plate. When it comes to the tiredness phase, the GOODMAN criteria have been utilized. Using grid independent testing, the outcomes that were initiated have been validated. The 3.15 KN of loads that were applied have been accounted for as the cause of the total deformation. There is a height of 7.0e-7 meters. For the applied load of 9.5E5 cycles, the information on life due practice has been proven and reached. Based on the plied load that was placed on the alloy, the equivalent stress estimated has been determined. The eq. stress reached a maximum value of 6.2E6 Pa at its highest point.

In this research, we employ Brownian dynamics simulations, density functional theory, and mean-field theory to explore the profound influence of shape anisotropy of magnetic nanoplatelets on suspension magnetic response. Each platelet is modelled as an oblate cylinder with a longitudinal point dipole, with an emphasis on strong dipolar interactions conducive to self-assembly. We investigate static structural and magnetic properties, characterising the system through pair distribution function, static structure factor, and cluster-size distribution. The findings demonstrate that shape-specific interactions and clustering lead to significant changes in reorientational relaxation times. Under zero field, distinctive modes in the dynamic magnetic susceptibility identify individual particles and particle clusters. In the presence of an applied field, the characteristic relaxation time of clusters increases, while that of single particles decreases. This research provides insights into the intricate interplay between shape anisotropy, clustering, and magnetic response in platelet suspensions, offering valuable perspectives for recent experimental observations.

Domain-specific languages and model-driven development are two promising approaches for tackling the complexity of software systems development. However, creating domain-specific modeling languages is a complex and lengthy task which makes the creation of DSMLs only feasible in large and complex projects. To alleviate this difficulty, we developed OPM/D, a visual meta-modeling language for the definition of domainspecific modeling languages. Languages in OPM/D are defined via a static structural meta-model of the language and a set of validation rules that define the non-structural constraints of the language. The language editor is created on-the-fly through interpretation of the static structure and validation rules, minimizing the time between language definition and its use. Our approach has been applied to define a subset of the OPM modeling language, and a prototype tools is being developed using the Eclipse platform and technologies.

Consumption of fish in Indonesia continuously increase from 2000 to 2014. Particularly fish farming in Java from 2006-2014 is quite high, so there need to be adequate facilities for fish farming. Responding to these challenges, we developed Offshore Cage Ocean FARMITS technology specifically designed For the southern waters of Java Island. This paper discusses the static structure strength analysis of deformation and maximum yield strength that occurs on the offshore cage structure of Ocean FARMITS. The frame structure made of hollow pipe made from HDPE will be placed at 4,41m Wave Height, with a period of 19s. Numerical simulations are performed to obtain a motion response RAO and structural response due to random waves. This Structure is then analyzed under mooring conditions with the Catenary Mooring configuration. Rope stress that occur due to environmental loads will give tension stress to the structure, resulting in the offshore cage structure to occur maximum stress and deformation. The result of this research is to prove that the structure that is made by HDPE able to restrain the tension force of mooring line stress. This has been validated by the standard of Practical Aspects of Offshore Aquaculture System Design from Aquaculture America, so this structure can be said to be operating safely under Indonesian Irregular Wave.

The static structure of quasi-two-dimensional colloidal mixtures of dumbbells and spheres is studied by optical microscopy. Colloidal dumbbells, produced by aggregation of colloidal spheres, are mixed with spherical particles and confined between two parallel glass walls. The static structural properties of this system are determined for various concentrations of spheres in the dilute limit of dumbbells. The dumbbell-sphere pair correlation function exhibits a strong angular dependence, and also shows that the presence of dumbbells favors the formation of triangular lattices even at sphere concentrations far from close packing.

This research used a model experimental system to explore the joint effects of resource fragmentation and resource deterioration on population dynamics. The system provides a rapid test of conservation theory and can aid in planning for large and expensive studies. The investigation subjected the sawtooth grain beetle, Oryzaephilus surinamensis (L.), to five experiments in which population abundance was monitored over time. Metapopulations were created by connecting adjacent vials of flour with rubber tubes. The metapopulations were arranged in rings, and food was replenished at two-week intervals. The experiments examined populations in (1) habitats becoming increasingly fragmented, (2) dynamically fragmenting structure with concurrent loss of resources over time, (3) static structure, dynamic resource loss and differing numbers of patches, (4) static structural arrangements with dynamic resource loss that mimic resource deterioration and destruction, and (5) static arrangements of connected fragments with an equal total amount of food in a few large patches or several small patches. Time series of stage-specific abundances were compared in repeated-measures ANOVA. The results show that populations respond in nonlinear ways to both the amount of food and area provided. Within a confined area, when food is plentiful, individual interaction limits population abundance. When the amount of food is reduced, population abundance becomes food dependent. Immediate increase in immature abundance was a characteristic of fragmentation while a delayed reduction of adults was characteristic of food reduction. The stage-specific interaction at intermediate food levels shows birth and death processes that control this system, and elucidates the relationship between area and food that is integral to the dynamics of patchy populations.

The lattice dynamics of potassium selenate is analyzed using a rigid-ion model with the selenate groups reduced to rigid bodies. The interatomic forces have been adjusted only using static structural data. The number of adjustable parameters varies from two to five. Such a simple model is already sufficient to reproduce semiquantitatively the phonon dynamics of the real system. In particular, the model exhibits the lattice instability leading to the existence of an incommensurate phase. The characteristics of the resulting soft mode agree with those observed experimentally. The calculated eigenvector, in excellent agreement with the experimental one, is rather insensitive to the details of the interactions. This explains the strong similarities of the incommensurate modulations in most ${\mathit{A}}_{2}$${\mathit{BX}}_{4}$ compounds. On the other hand, the form of the soft-phonon branch strongly depends on the force model. It is sufficient to fit the model to the static structure observed at 145 K instead of the one at room temperature, to provoke a conspicuous softening of the branch. The branch minimum is specially sensitive to some potassium-oxygen interactions. The relative size of the cations plays an essential role in the origin of the incommensurate instability. For comparison the results of a similar analysis for ${\mathrm{Cs}}_{2}$${\mathrm{SeO}}_{4}$ are presented. In this case, the unstable or ``soft'' character of the lowest ${\mathrm{\ensuremath{\Sigma}}}_{2}$ branch disappears.