Presence Of Structural Heterogeneity Research Articles

Asymmetric effects of interaction and dispersal graphs on evolutionary dynamics

Population structure is a critical factor in shaping evolutionary dynamics. It constrains not only who interacts with whom, but also who learns from whom. In many real-world cases, such spatial constraints can lead to asymmetric interaction and strategy dispersal. For example, individuals who are geographically and socially too distant to interact physically may still learn from each other through social media. Despite the ubiquity of the asymmetry, their impact on evolutionary outcomes, particularly in the presence of structural heterogeneity, is not well understood. In this paper, we investigate their influence on evolutionary dynamics. Our analytical and simulation results demonstrate that although population structure can lead to the formation of clusters of cooperators, disrupting the balance between the interaction and dispersal graphs can severely impede cooperation. Moreover, we find that increased network heterogeneity exacerbates the cooperation-inhibiting effects. We also examine the roles of the interaction and dispersal networks separately. By modifying the connections in each network, we find that altering the dispersal network has a more pronounced effect on cooperation compared to the interaction network. Our work emphasizes the importance of the correlation between interaction and strategy dispersal and highlights that modifying the paths of strategy or information dissemination can be a more effective way of promoting social prosperity than modifying the interaction networks.

Heterogeneous Monetary Zone and Macroprudential Policy: The Case of the Waemu Zone

This article raises the question of the conduct of a common macroprudential policy aimed at correcting specific financial imbalances in the presence of structural heterogeneity that characterizes the monetary zone, in this case the WAEMU zone. For this reason, we develop a neo-Keynesian DSGE[1] model in an open economy with two countries, namely the core countries and those of the periphery, with increased financial frictions. The results show that in the presence of structural heterogeneities, country-adjusted macroprudential measures, as opposed to a common macroprudential policy, are the best way to reduce specific financial imbalances. However, in financially integrated economies, the existence of negative externalities implies the need to coordinate national macroprudential policies in order to increase the degree of currency area optimality.[1] Dynamic Stochastic General Equilibrium

УСЛОВИЯ ФОРМИРОВАНИЯ СТРУКТУР МОЗАМБИКСКОГО БАССЕЙНА (ФИЗИЧЕСКОЕ МОДЕЛИРОВАНИЕ)

Based on the results of physical modeling, the conditions of formation of the Mozambique Ridge and the Beira High, formed during the opening of the Mozambique Basin, are considered. The Mozambique Ridge is a series of blocky uplifts rising up to 3500 m above the seafloor. One of the most probable hypotheses of the ridge origin suggests its partial separation from the margin of the African continent as a result of plume activity. Modern studies show that the northeastern part of the ridge is composed of thinned continental crust overlain by sedimentary cover, while its southern part is characterized by a large number of extrusive centers, indicating increased magmatic activity. Experimental studies have shown that the formation of the Mozambique Ridge occurred under the conditions of the African-Antarctic continental rift with the presence of structural heterogeneities in the lithosphere of the African continent and the influence of a hot spot. The Beira High is a continental block that was separated from Antarctica during the split of Gondwana.

СТРОЕНИЕ ТЕКТОНОСФЕРЫ И УСЛОВИЯ ФОРМИРОВАНИЯ МОЗАМБИКСКОГО ХРЕБТА: ПЛОТНОСТНОЕ И ФИЗИЧЕСКОЕ МОДЕЛИРОВАНИЕ

The tectonosphere and formation conditions of the Mozambique Ridge are considered. The Mozambique Ridge is located in the southwestern part of the Indian Ocean between the Natal and the Mozambique Mesozoic Basins. The way how the ridge formed remains debatable. The anomalous structure of the crust of the Mozambique Ridge can be explained either by underplaying - thickening of the oceanic crust from below due to magmatism, or by stretching and thinning of the continental crust. Based on gravitational and magnetic field anomalies, seismotomography and other geological and geophysical information, density modeling was carried out along four profiles. Physical modeling determined the conditions of formation of the Mozambique Ridge. It formed due to the splitting of the African-Antarctic continent, the presence of structural heterogeneities in the lithosphere of the African continent and the influence of the Karoo plume.

An insight into the dissolution of cellulose in 1-butyl-3-methylimidazolium chloride-DMSO binary Mixture: Exploring the dynamics of rhodamine 6G and fluorescein

The change in the interaction of solute and the ionic liquid-DMSO mixture with the extent of dissolution of cellulose is investigated through fluorescence spectroscopic studies. This study aims to provide an insight into the dissolution of cellulose in ionic liquid-DMSO mixtures in terms of photophysical aspects. Although the rheology and viscoelastic properties of ionic liquid-DMSO-cellulose mixtures are well studied in the early literature, there is a lack of photophysical investigation. For this reason, we have taken two oppositely charged but structurally similar solutes, fluorescein sodium salt (Fl-Na) and rhodamine 6G (R6G), to investigate their rotational and translational dynamics in the mixture. Analysis of the time-resolved fluorescence anisotropy data using the Stokes-Einstein-Debye (SED) theory suggests that the rotational relaxation times of the solutes follow near stick hydrodynamics in absence of cellulose. The solutes experienced a strong interaction in pure DMSO and with the increasing concentration of BmimCl, the specific interaction between the solvent and the solute decreases as indicated in decreasing Cobs values. While in presence of cellulose, the solutes follow near slip hydrodynamics in low BmimCl concentration but at higher concentration, the specific interaction increases. From the temperature-dependent anisotropy, we have observed that both R6G and Fl-Na follows the super-stick trend, and with increasing temperature specific interaction between the solute and solvent increases. On the other hand, in presence of cellulose, their rotational reorientation times appear close to the slip boundary condition at low temperature, and with increasing temperature, it approaches close to the stick boundary. Fluorescence Correlation Spectroscopy (FCS) indicates the presence of structural heterogeneity in the BmimCl-DMSO mixture formed due to the segregation of the hydrophobic chain of the ionic liquid. Therefore, the experimental results of this work suggest that the dissolution of cellulose modulates the dynamics of the solutes in ionic liquid–DMSO mixtures.

Terrane Boundary Reactivation, Barriers to Lateral Fault Propagation and Reactivated Fabrics: Rifting Across the Median Batholith Zone, Great South Basin, New Zealand

AbstractProminent preexisting structural heterogeneities within the lithosphere may localize or partition deformation during tectonic events. The NE‐trending Great South Basin, offshore New Zealand, formed perpendicular to a series of underlying crustal terranes, including the dominantly granitic Median Batholith Zone, which along with the boundaries between individual terranes exert a strong control on rift physiography and kinematics. We find that the crustal‐to‐lithospheric scale southern terrane boundary of the Median Batholith Zone is associated with a crustal‐scale shear zone that was reactivated during Late Cretaceous extension between Zealandia and Australia. This reactivated terrane boundary is oriented at a high angle to the faults defining the Great South Basin. We identify a large granitic laccolith along the southern margin of the Median Batholith, expressed as subhorizontal packages of reflectivity and acoustically transparent areas on seismic reflection data. The presence of this strong granitic body inhibits the lateral southwestward propagation of NE‐trending faults, which segment into a series of splays that rotate to align along the margin as they approach. Further, we also identify two E‐W‐ and NE‐SW‐oriented basement fabrics, likely corresponding to prominent foliations, which are exploited by small‐scale faults across the basin. We show that different mechanisms of structural inheritance are able to operate simultaneously, and somewhat independently, within rift systems at different scales of observation. The presence of structural heterogeneities across all scales needs to be incorporated into our understanding of the structural evolution of complex rift systems.

Nonlinear acoustics in studies of structural features of materials

Abstract

IMPROVEMENT OF THICK-WALLED MACHINE AND UNIT CASING REPAIR TECHNOLOGY

To date, one of the most significant problems in the development of petroleum engineering is the increase in the productive life of machines and units, as well as the reduction of material, energy and labor resources. During the operation of oil and gas equipment, over time, the destruction of elements often occurs at welding joints due to thermal and force loads, corrosion and other factors. The cause of failure in welded joints of base parts can be explained by presence of structural heterogeneity and stresses remaining after welding. Electric arc welding is currently almost the only applicable technology for the repair of oil and gas equipment requiring welding operations. A highly concentrated source of thermal energy and various deformation capacities of parts cause residual stresses that lead to a change in shape, a decrease in strength, a decrease in the corrosion resistance of the metal, which have a negative effect on the construction operation. Currently, there used a conservative repair technology with manual arc welding of coated electrodes with the associated heating of the defective area and, if necessary, subsequent heat treatment. Welding is accompa- nied by a complex of simultaneous processes, the main ones are: thermal action on the metal in the zone of thermal influence, metallurgical pro- cesses in the weld pool and crystallization of metal in the volume of the weld pool. The developed welding technology, consisting in combining the con- comitant cooling and ultrasonic treatment, allows improving the mechan- ical properties of the welded joint, as well as avoiding the costly accom- panying heating during welding.

Representing heterogeneity in structural relationships among multiple choice variables using a latent segmentation approach

Travel model systems often adopt a single decision structure that links several activity-travel choices together. The single decision structure is then used to predict activity-travel choices, with those downstream in the decision-making chain influenced by those upstream in the sequence. The adoption of a singular sequential causal structure to depict relationships among activity-travel choices in travel demand model systems ignores the possibility that some choices are made jointly as a bundle as well as the possible presence of structural heterogeneity in the population with respect to decision-making processes. As different segments in the population may adopt and follow different causal decision-making mechanisms when making selected choices jointly, it would be of value to develop simultaneous equations model systems relating multiple endogenous choice variables that are able to identify population subgroups following alternative causal decision structures. Because the segments are not known a priori, they are considered latent and determined endogenously within a joint modeling framework proposed in this paper. The methodology is applied to a national mobility survey data set to identify population segments that follow different causal structures relating residential location choice, vehicle ownership, and car-share and mobility service usage. It is found that the model revealing three distinct latent segments best describes the data, confirming the efficacy of the modeling approach and the existence of structural heterogeneity in decision-making in the population. Future versions of activity-travel model systems should strive to incorporate such structural heterogeneity to better reflect varying decision processes across population subgroups.

Effects of heterogeneity on recrystallization kinetics of nanocrystalline copper prepared by dynamic plastic deformation

Recrystallization and mechanical behavior of nanocrystalline copper prepared by dynamic plastic deformation (DPD) and DPD with additional cold-rolling (DPD+CR) were investigated, with an emphasis on the effects of heterogeneity within the deformation microstructure. The DPD sample was found to develop a heterogeneous structure, consisting of regions with different textures and microstructures. This heterogeneity within the deformed structure leads to the formation of severely clustered grains in partially recrystallized samples. The recrystallization kinetic curve shows an Avrami exponent less than 1, which is explained using a two-stage kinetics model incorporating the heterogeneity. The heterogeneity of the DPD sample is largely reduced by applying additional rolling. This change in deformation path leads to a more random distribution of the recrystallized grains and more conventional recrystallization kinetics. The hardness of the two samples was measured, and the mechanical properties before and after partial recrystallization of both samples are discussed based on the presence of structural heterogeneities on the macroscopic and the microscopic scale.

Aldehyde Complexes with Protonated Peptides in the Gas Phase

This Article presents a study of aldehyde complexes with peptide ions formed by bimolecular collisions in the gas phase. Desolvated ions generated by electrospray ionization are stored within a radio frequency (RF) ion trap and exposed to aldehyde vapor. Mass spectrometry measurements were performed on the resulting aldehyde complexes formed with single amino acids (LysH(+), HisH(+), and ArgH(+)) and polypeptides [Pro(n)-Lys+2H](2+) and [(Gly-Ser)(m)-Lys+2H](2+). These data identify several interesting and unexpected aspects of the aldehyde complex kinetics. It is observed that the formation of stable complexes requires the presence of water vapor. The formation kinetics of aldehyde-peptide complexes exhibits multiexponential time dependence that is modeled by interactions in the presence of structural heterogeneity. Aldehyde binding appears to involve a competition between conformers with unhindered access to protonation sites and conformers with intramolecular solvation of these sites. Proton transfer to the aldehyde ligand is responsible for the loss of the complexes. This is supported by proton affinity calculations and identified by reaction products exhibiting loss of protonation by the parent ion accompanied by the appearance of aldehyde cations.

Thermal and structural heterogeneities during cooking of a starch-based product by a non-intrusive ring sensor

Thermal treatment of many foodstuffs is a common operation in the food industry in order to increase the storage life of the marketed product. The control and the knowledge of heterogeneity of treatment which may occur during cooking of texturant products in process equipment are essential to ensure food quality. In this paper, a non-intrusive ring sensor device has been set-up at the inner wall of a vessel as made in tomographic processes. Based on electrical properties measurement and a novel approach in the way the sensor is applied, the presence of structural heterogeneities was detected. This device has been also used to estimate in real time thermal heterogeneities during cooking of a starch-based product in an agitated vessel. The paper describes in details the measuring system, the reconstruction algorithm for the temperature fields and the structure change detection algorithm. Pictures visualizing the temperature fields during cooking of a model fluid are reported in the last section.

Near-infrared-induced Transitions in the Manganese Cluster of Photosystem II: Action Spectra for the S2 and S3 Redox States

The Mn4Ca complex that is involved in water oxidation in PSII is affected by near-infrared (NIR) light in certain redox states and these phenomena can be monitored by electron paramagnetic resonance (EPR) at low temperature. Here we report the action spectra of the NIR effects in the S2 and S3 states in PSII from plants and the thermophilic cyanobacterium Thermosynechococcus elongatus. The action spectra obtained are very similar in both S states, indicating the presence of the same photoactive form of the Mn4Ca complex in both states. Since the chemical nature of the photoactive species is not known, an unequivocal interpretation of this result cannot be made; however, it appears to be more easily reconciled with the view that the redox state of the Mn4Ca cluster does not change from the S2 to the S3 transition, at least in those centers sensitive to NIR light. The temperature dependence of the NIR effect and the action spectra for S2 indicate the presence of structural heterogeneity in the Mn4Ca cluster.

Molecular Level Structural Heterogeneity in Poly(ether−ester)/Poly(vinyl chloride) Blend Characterized by Cross-Polarization/Magic Angle Spinning 13C Nuclear Magnetic Resonance Spectroscopy

A blend of poly(ether-ester) and poly(vinyl chloride) (PVC) was examined by dynamic mechanical analysis and cross-polarization/magic angle spinning (CP/MAS) 13 C NMR spectroscopy. The presence of structural heterogeneity in the solid blend was identified by the temperature dependence of its frequency-swept viscoelastic behavior. In the CP/MAS 13 C NMR experiment, analysis of the magnetization decay of specific carbons as a function of delay time determined the proton spin-lattice relaxation times in the laboratory frame, T 1 , and the rotating frame, T 1ρ , for the two polymers in their respective pure states and in the 50/50 blend. This analysis provided more precise information pertaining to the microheterogeneity and the molecular state of mixing in the blend. The single-exponential decay of T 1 relaxation of the blend confirmed a homogeneity on a characteristic length of 26 nm estimated from the spin diffusion process. The double decompositions in the T 1ρ relaxation of component polymers in the blend indicated a coexistence ofa mixed and two structurally heterogeneous phases which corresponded to poly(ether-ester) hard segments and PVC microcrystallites. The maximum size of the microheterogeneous phases was estimated to be ca. 24 A.

Estrogen Synthesis in Leydig Cells: Structural-Functional Correlations in Necturus Testis1

The intratesticular site of estrogen biosynthesis is still somewhat controversial. Since the testis of the urodele amphibian Necturus maculosus has exceptionally high aromatase activity and is organized into a distinct glandular region that can be readily separated from another component made up mainly of seminiferous lobules, a study was undertaken to correlate function and structure of these two regions. When microsomal preparations were incubated with radiohabeled substrates, two key enzymes in estrogen biosynthesis, aromatase and 1 7a-hydroxylase, were found to be concentrated in the glandular tissue. Also, spectral measurements showed that eytochrome P450 speciesthatbind androstenedione and progesterone, respective steroidal substrates for aromataseand 17cs-hydroxylase, were distributed between the two zones in ratios similar to their steroidogenic activities. The relative yields of radioimmunoassayable estrogen and androgen from cultured cells derived from each zone was further evidence fot the higher steroidogenic capacity of the glandular tissue. Observations with the electron microscope indicate that active steroid synthesis in the glandular tissue could be attributed solely to numerous, highly differentiated Leydig cells, which are characterized by enormous volumes of smooth endoplasmic reticulum and mitochondria with tubular cristae. The presence of structural heterogeneities in the cell population in this region further suggests there may be functional differences among the various Leydig cell types. Although differentiating Leydig cells were seen surrounding the seminiferous lobules, they had little smooth endoplasmic reticulum. Based on structural features, it is improbable that differentiating Leydig cells, Sertoli cells, or elements other than differentiated Leydig cells in either the glandular or lobular tissues are steroidogenically active. The functional significance of testicular estrogen is still unknown. Because of the uniquely high Leydig cell aromatase aetivity, the specialized anatomy of the urodele testis, and an annual cycle in which temporal changes are protracted, we conclude that Necturus is a useful animal model for further investigation of this problem.