Mechanism Of Redistribution Research Articles

Experimental evidence of magnetic flux pumping in ASDEX upgrade

In high-β scenarios with on-axis co-current electron cyclotron current drive, which normally lowers q 0 below unity, the absence of sawteeth suggests the involvement of an additional current redistribution mechanism beyond neoclassical current diffusion. This is supported by imaging motional Stark effect diagnostic measurements, which indicate that q 0 remains consistently around 1. This phenomenon is observed in the presence of a 1/1 mode, indicating its potential role in the current redistribution. It is shown that the mode’s ability to modify the central current and suppress sawteeth increases with plasma pressure. These findings align with a recent theoretical model, which predicts a pressure threshold for sawtooth avoidance by a 1/1 quasi-interchange mode and where this threshold increases with the strength of inward current diffusion. Moreover, the advantages of the flux pumping scenario for future machines are highlighted.

Co2P/CoP heterostructures with significantly enhanced performance in electrocatalytic hydrogen evolution reaction: Synthesis and electron redistribution mechanism

Co2P/CoP heterostructures with significantly enhanced performance in electrocatalytic hydrogen evolution reaction: Synthesis and electron redistribution mechanism

Tough and Robust Metallosupramolecular Hydrogels Enabled by Ti3C2Tx MXene Nanosheets.

Recently, many tough synthetic hydrogels have been created as promising candidates in fields such as smart electronic devices. In this paper, we propose a simple strategy to construct tough and robust hydrogels. Two-dimensional Ti3C2Tx MXene nanosheets and metal ions were introduced into poly(acrylamide-co-acrylic acid) hydrogels, the MXene nanosheets acted as multifunctional cross-linkers and effective stress-transfer centers, and physical cross-links were formed between Fe3+ and carboxylic acid. Under deformation, the coordination interactions exhibit reversible dissociation and reorganization properties, suggesting a novel mechanism of energy dissipation and stress redistribution. The design enabled the hydrogel to exhibit outstanding and balanced mechanical properties (tensile strength of up to 5.67 MPa and elongation at break of up to 508%). This study will facilitate the diverse applications of metallosupramolecular hydrogels.

Annual Festivals and Potlatch-like Forms of Redistribution in Early Political Formations of Upper Guinea

The article proposes a reconstruction of potlatch-like forms of redistribution in early political formations of Upper Guinea. Annual festivals (such as Aкanian Odwira and Dahomeyan Anun'gbome) are interpreted as peculiar inversions of gafol (poludye in Russian history) and potlatch-like institution. These multifunctional festivals and gafol were the major mechanisms of alienation and redistribution of the surplus product in the early political formations.

An accurate analytical model for stress overload around multiple fiber breakpoints in unidirectional fiber reinforced plastic

Efficient and accurate calculation of stress overload and stress redistribution near the fiber breakpoint is the basis for simulating the tensile damage evolution of unidirectional fiber reinforced plastic (FRP), and it is also the premise for predicting the tensile-tensile fatigue life. In this study, an efficient finite element (FE) model with a large number of fibers was developed based on the FE method to calculate stress concentration factor (SCF) near multiple breakpoints, and the calculation time only takes 3 min on average. The FE model is used to efficiently calculate multiple breakpoints and the stress distribution near the breakpoint considering the interface debonding. Based on the efficient FE model, an analytical model is developed to calculate the stress overload superposition around multiple breakpoints. In this analytical model, the shear stress distribution near the broken fiber elements is established based on the experiment, and the stress redistribution mechanism near the breakpoint in FRP with random distribution of fibers is established. Moreover, the calculation method of stress overload near multiple break points is established, and the FE method is verified.

Stress redistribution in a multilayer chamber for compressed air energy storage in abandoned coalmine: Elastic analytical insights and material choice

AbstractCompressed air energy storage (CAES) is attracting attention as one of large‐scale renewable energy storage systems. Its gas storage chamber is one of key components for its success. A successful utilization of an abandoned coalmine roadway depends on the stability of the gas storage chamber. The chamber is a multilayer structure and the redistribution of the stress and displacement in each layer is critical to the chamber stability. So far, this redistribution mechanism under any lateral pressure coefficient and internal air pressure has been unclear and thus a quick and easy evaluation on the CAES chamber stability becomes difficult. In this study, the redistributions of stress and displacement in each layer are analytically solved based on complex variable function theory. First, the stress and displacement in three CAES multilayer structures are obtained under any lateral pressure coefficient and internal air pressure. Then, a comprehensive parameter b1 is obtained to describe the redistribution of stress and displacement in rock mass, lining layer, and grout layer. Its linkage with lateral pressure coefficient, internal air pressure, and material properties is analytically expressed. Thirdly, an analytical expression is obtained for the influence range of internal air pressure on chamber stress. Finally, the role and selection of lining and grouting layers are explored at different lateral pressure coefficient and internal air pressure. It is found that the CAES chamber stability can be effectively and quickly evaluated by these analytical solutions and comprehensive parameters and enhanced by a material with low bulk modulus but high shear modulus.

An integrated section model to enable simulating composite slabs in fire simply as modelling a flat slab

Modelling slabs is vitally necessary when simulating building structures in fire. The composite action between slabs and beams and tensile membrane action after fire induced deflections significantly reshape the load redistribution mechanisms and failure patterns. Modelling slabs particularly composite slabs of ribbed sections as a common choice of modern steel structures is a challenging task. Currently, those existing modelling approaches, such as beam & shell model and strip models, require elements for ribbed and flat parts separately, which produces much complexity and ideally it can be solved using a suitable section model to appropriately represent the behaviour. This paper begins with formulating the theoretical base of state determination in the integrated composite section, which enables correct deformation distribution to ribbed and flat subsections. While being compatible to typical modelling infrastructure for slabs, the integrated section model has demonstrated excellent capability in comparison to the strip models and fire tests. Even using a coarse mesh scheme (e.g. 8 × 6 elements), the prediction error of mid-span deflection remains low (around 10%). The appealing benefit is further shown in modelling Cardington Corner fire test, which significantly reduces the efforts of determining geometric details, the number of nodes & elements, and the computation time cost.

Taxes, Inequality, and Equal Opportunities.

Extreme inequality represents a grave challenge for impoverished individuals and poses a threat to economic growth and stability. Despite the fulfillment of affirmative action measures aimed at promoting equal opportunities, they often prove inadequate in effectively reducing inequality. Mathematical models and simulations have demonstrated that even when equal opportunities are present, wealth tends to concentrate in the hands of a privileged few, leaving the majority of the population in dire poverty. This phenomenon, known as condensation, has been shown to be an inevitable outcome in economic models that rely on fair exchange. In light of the escalating levels of inequality in the 21st century and the significant state intervention necessitated by the recent COVID-19 pandemic, an increasing number of scholars are abandoning neo-liberal ideologies. Instead, they propose a more robust role for the state in the economy, utilizing mechanisms such as taxation, regulation, and universal allocations. This paper begins with the assumption that state intervention is essential to effectively reduce inequality and to revitalize the economy. Subsequently, it conducts a comparative analysis of various taxation and redistribution mechanisms, with a particular emphasis on their impact on inequality indices, including the Gini coefficient. Specifically, it compares the effects of fortune and consumption-based taxation, as well as universal redistribution mechanisms or targeted redistribution mechanisms aimed at assisting the most economically disadvantaged individuals. The results suggest that fortune taxation are more effective than consumption-based taxation to reduce inequality.

Incentive Mechanisms to Integrate More Renewable Energy in Electricity Markets in China

China has made significant progress in developing renewable energy, but challenges in integrating variable sources like wind, solar, and hydro power persist. Existing research has a regional focus and lacks a comprehensive understanding of integration challenges in specific regions. Moreover, research concentrates on individual energy types rather than multiple sources. Addressing these challenges requires a deeper analysis of market rules, incentives, and mechanisms for integrating numerous renewable energy types. The existing research also overlooks crucial aspects like energy consumption, grid planning, and power market mechanisms. To promote renewable energy integration effectively, policymakers must address these interconnected factors through comprehensive investigations and research efforts. This study proposes tailored solutions to encourage integration in China based on international experiences, such as Brazil’s contract markets and electricity redistribution mechanism, the Nordic spot market, and California’s negative pricing mechanism. The strategies derived from global practices for China’s renewable energy integration include diverse trading mechanisms, expanded contract markets, optimized local consumption, fortified grid infrastructure, and improved market mechanisms.

Application of layer view factor method in high temperature thermal storage packed bed

This study provides a comprehensive evaluation of radiation effects on the thermal behavior of a packed bed using a discrete model for heat transfers integrating a novel method called Layer View Factor for view factors estimation, which significantly decreases computational time by less than 9000 times compared to the parallel ray tracing method. The model is validated and strongly aligned with experimental data at 823K, with a maximum mean bias and root mean square errors of ±4.5K and 10K, respectively. Analyses of temperature profiles and thermocline lengths for charging, discharging, and stand-by processes at a charge temperature of 1473K were performed, finding a thermal flattening effect with radiation, leading to lower peak temperatures and quicker thermocline length evolutions. Notably, the stand-by process exhibited the largest impact, with a maximum temperature difference of up to 100K compared to the non-radiation case. Moreover, analysis of the temperature and energy of discharge found that the maximum discharge temperature drops below 90% of the charge temperature when radiation is included. Finally, efficiency analysis of the processes showed differences of up to 2% between having or not the radiation effect, aiming its role as a redistribution mechanism in the packed bed’s temperature.

INCREASE IN PRICES OF STAPLES IN THE MONTH OF RAMADAN IN THE PERSPECTIVE OF ISLAMIC ECONOMIC PHILOSOPHY

Purpose- The objective of this research is to analyze the phenomenon of the increase in prices of basic commodities during Ramadan from the perspective of Islamic economic philosophy. This study aims to understand the factors influencing price hikes, their impact on society, and to find solutions in line with the principles of Islamic economics to address the issue. Methodology- This research utilizes a qualitative and descriptive approach. Data will be collected through literature review, document analysis, and interviews with Islamic economics experts. Data analysis will be conducted using deductive and inductive approaches, while referring to relevant Islamic economic principles. Findings- Based on this study, it was found that the increase in prices of basic commodities during Ramadan can be attributed to several factors. One of the main factors is the high demand due to increased consumption during the fasting month. Additionally, other factors such as price speculation, changes in consumer behavior, and supply disruptions can also contribute to price hikes. The impact of the price increases of basic commodities during Ramadan is strongly felt by the society, particularly those with low incomes. The price hikes can lead to economic difficulties, social instability, and increased economic disparity within the community. This contradicts the principles of Islamic economics that emphasize justice, sustainability, and concern for the welfare of society. Conclusion- Based on this research, it can be concluded that the increase in prices of basic commodities during Ramadan, from the perspective of Islamic economic philosophy, is a complex issue that requires solutions aligned with the principles of Islamic economics. Potential solutions include enhancing market transparency, reducing price speculation, promoting local production, encouraging active participation of the community, and strengthening mechanisms for fair economic redistribution. Implementing Islamic economic principles such as justice, sustainability, and social welfare can help address the issue of price hikes during Ramadan and create a more stable and sustainable economy. In this context, the role of the government, Islamic financial institutions, and society at large is crucial in working together to address this problem and ensure equitable economic well-being for all segments of society. Keywords: Increase in prices, basic commodities, Ramadan, Islamic economic philosophy, price hikes JEL Codes: D40, E31, P48

THE EFFECTIVENESS OF THE DEVELOPMENT OF TERRITORIES IN THE STATE REGIONAL SYSTEM POLITICIANS

It was determined that the development of territories depends on the choice of strategy, tactics and implementation tools regional policy of the state. And therefore, at the current stage of global transformations, they are expedient and permanently improve, as current practice shows approaches to managing the development of domestic territories. Trends and prospects of development are studied in territorial units of Ukraine in terms of implementation of the chosen strategy and current state regulations and regional policy. The study of the problem was carried out thanks to the application of methods of comparison, abstraction, analysis and generalization, as well as tabular and graphical modelling. It was determined that the prospects for the development of territories primarily depend on the strategy and tactics implementation of the state regional policy, which should take into account the dynamism of socio-economic development, the rate of digitization of the economy and the level of innovation and technology regions of highly developed countries of the world, with which domestic regions are becoming more and more difficult to compete. A set of measures was proposed to optimize the processes of managing the development of territories, in particular, the creation of mechanisms for combating post-pandemic consequences, stimulating purchasing consumer demand at the local level, improvement of tax policy, creation of favourable conditions for improving the qualification level of employees, rationalization of the financial redistribution mechanism resources between different territories, as well as between regional and state budgets, dissemination of effective anti-corruption practices at the local level. Prospects for the creation of territorial ones have been determined by communities taking into account positive and negative factors to reveal strong and weaknesses in order to identify opportunities and threats to their development at the regional level levels using a SWOT analysis. Ways to improve regional policy are proposed.

The response of diagrid structures to fire

The diagrid structural system has seen significant uptake in medium to high rise buildings because of the architectural and resource advantages that it provides. These arise mainly as a result of flexibility in the topology that this particular structural solution provides. However, as a result of the way in which diagrids carry both horizontal and vertical loading, the diagrid structure itself may be susceptible to fire in ways which are not immediately obvious on the basis of our understanding of more traditional rectilinear construction forms. This study addresses this to improve our understanding of diagrid structures' response to fire. A comprehensive structural analysis on 45 fire load cases is conducted, considering different fire locations and sizes, using parametric design tools and finite element analysis software. The results provide valuable insights into the load redistribution and collapse mechanisms of diagrid structures in fire conditions.

Mid-infrared Laser Spectroscopy of Jet-Cooled Formic Acid Trimer: Mode-Dependent Line Broadening in the C-O Stretching Region.

Building on recent progress in the vibrational spectroscopy of the formic acid trimer, we present the first high-resolution measurements of the jet-cooled laser absorption spectrum of (HCOOH)3. The spectra of the lowest- and highest-frequency C-O stretching fundamentals are analyzed whereas the third band is not observed, complicated by monomer and dimer absorptions at 1219 cm-1 (8.2 μm). Vibration-rotation parameters are obtained for the band at 1172.31512(68) cm-1 whereas the C-O stretch at 1246.33(5) cm-1 exhibits a significantly larger breadth, allowing only resolution of the coarse PQR structure. Vibrational predissociation can be ruled out, and intramolecular vibrational redistribution mechanisms are discussed, particularly coupling to the concerted proton exchange within the cyclic dimer subunit. Ultimately, the question remains open. The prospects of high-resolution measurements of other trimer bands or isotope substitution experiments, which might assist in revealing the mode-specificity of the underlying broadening mechanisms, are discussed.

Percolation phase transition in the heterogeneous multi-coupled interdependent network

In previous studies, complex system models have often been set up in an oversimplified manner and the failure mechanism for nodes affected by each other is not correspond to reality. Accordingly, we develop a new model of heterogeneous multi-coupled interdependent networks and analyze the change in the giant component of the network after the attack in conjunction with the load redistribution mechanism. We first analyze the cascading failure process of the network analytically by recursive methods, estimate the critical phase transition threshold and the size of the giant component of the remaining network after network percolation, and find that the threshold of the WS sub-network is positively related to the average degree, and the BA sub-network is related to the power exponent λ of the distribution. When λ is less than or equal to 2, there is always a giant component in the network. After λ is greater than 3.4788⋯, there is no giant component. When λ is between 2 to 3.4788⋯, we found that the threshold of the sub-network is more influenced by the proportion of attacks (p1 and p2), and when p1 is larger, the sub-networks interact with each other, resulting in a smaller threshold for the BA sub-network, while the threshold of the WS sub-network is smaller in other cases. Finally, the cross-sectional comparison illustrates that as λ increases to 3.4788⋯, the robustness of the BA sub-network increases, contrary to the findings for single-layer networks. Overall, the heterogeneous multi-coupled interdependent network is more robust, and the giant component is greatly affected by the low robust sub-network, but its existence is related to the stock of nodes.

Response of cardiac pulse parameters in humans at various inclinations via 360° rotating platform for simulated microgravity perspective

On the Earth, the human body is designed and adapted to function under uniform gravitational acceleration. However, exposure to microgravity or weightlessness as experienced by astronauts in space causes significant alterations in the functioning of the human cardiovascular system. Due to limitations in using real microgravity platforms, researchers opted for various ground-based microgravity analogs including head-down tilt (HDT) at fixed inclination. However, in the present study, an investigation of response of various cardiac parameters and their circulatory adaptation in 18 healthy male subjects was undertaken by using an indigenously developed 360° rotating platform. Cardiac pulse was recorded from 0° to 360° in steps of 30° inclination using piezoelectric pulse sensor (MLT1010) and associated cardiac parameters were analyzed. The results showed significant changes in the pulse shape while an interesting oscillating pattern was observed in associated cardiac parameters when rotated from 0° to 360°. The response of cardiac parameters became normal after returning to supine posture indicating the ability of the cardiovascular system to reversibly adapt to the postural changes. The observed changes in cardiac parameters at an inclination of 270°, in particular, were found to be comparable with spaceflight studies. Based on the obtained results and the proposed extended version of fluid redistribution mechanism, we herewith hypothesize that the rotation of a subject to head down tilt inclination (270°) along with other inclinations could represent a better microgravity analog for understanding the cumulative cardiac response of astronauts in space, particularly for short duration space missions.

Peripheral origin exosomal microRNAs aggravate glymphatic system dysfunction in diabetic cognitive impairment.

Cognitive dysfunction is one of the common central nervous systems (CNS) complications of diabetes mellitus, which seriously affects the quality of life of patients and results in a huge economic burden. The glymphatic system dysfunction mediated by aquaporin-4 (AQP4) loss or redistribution in perivascular astrocyte endfeet plays a crucial role in diabetes-induced cognitive impairment (DCI). However, the mechanism of AQP4 loss or redistribution in the diabetic states remains unclear. Accumulating evidence suggests that peripheral insulin resistance target tissues and CNS communication affect brain homeostasis and that exosomal miRNAs are key mediators. Glucose and lipid metabolism disorder is an important pathological feature of diabetes mellitus, and skeletal muscle, liver and adipose tissue are the key target insulin resistance organs. In this review, the changes in exosomal miRNAs induced by peripheral metabolism disorders in diabetes mellitus were systematically reviewed. We focused on exosomal miRNAs that could induce low AQP4 expression and redistribution in perivascular astrocyte endfeet, which could provide an interorgan communication pathway to illustrate the pathogenesis of DCI. Furthermore, the mechanisms of exosome secretion from peripheral insulin resistance target tissue and absorption to the CNS were summarized, which will be beneficial for proposing novel and feasible strategies to optimize DCI prevention and/or treatment in diabetic patients.

Study on progressive collapse demolition method of double-layer space truss

This paper conducted a demolition test of a double-layer space truss (DLST) to investigate more efficient, safe and environmentally friendly demolition methods of truss systems. The high-speed 3D displacements of representative joints and the global dynamic strain response of the structure were well collected. The internal force redistribution and load-carrying mechanisms of DLST structures during demolition were explored. The results indicate that new equilibrium states were sought in the DLST through local and global internal force redistribution. When the main force transmission members were removed, the load-carrying mechanism of the DLST underwent sudden changed, which resulted in a snap-through in the structural load-carrying capacity. The test DLST exhibited three load-carrying mechanisms in time sequence during the proposed demolition: arch action, catenary action, and beam action. The theoretical vertical load-carrying capacity provided by each load-carrying mechanism was investigated separately. Finally, a progressive collapse demolition method was presented for the engineering DLST structures subjected to certain demolition external loads.

Right ventricular visualization at SPECT perfusion imaging before and after revascularization in patients with postinfarction cardiosclerosis

Aim. To evaluate the intersystemic (between the myocardium of the left coronary artery system and the right coronary artery system redistribution mechanisms of perfusion in the myocardium after revascularization in patients with coronary artery disease with focal cardiosclerosis using gated single photon emission computed tomography. Сardiosclerosis foci were initially identified by magnetic resonance imaging. Material and Methods. The study included 17 patients with coronary artery disease with multivessel coronary disease and large-focal cardiosclerosis according to the results of magnetic resonance imaging with contrast; the diagnosis of left ventricular aneurysm was established in 14 patients, the focal subendocardial cardiosclerosis was diagnosed in 3 patients. For various reasons, all patients underwent myocardial revascularization without the left ventricle reconstruction (coronary artery bypass grafting in 10 patients, percutaneous coronary intervention in 7 patients). Magnetic resonance imaging was used as the gold standard for focal cardiosclerosis before revascularization. All patients before and after revascularization underwent gated single photon emission computed tomography with MIBI scan. During the initial analysis of peaks on the profile slices of coronal and transversal midsections passing along the lateral walls of the left and right ventricles, we did not notice a clear visualization of in 8 patients (group 1), while an increased MIBI scan accumulation in the right ventricle myocardium was clearly visualized in 9 patients (group 2). Based on the peaks height of profile curves, we compared changes in the maxima of radiopharmaceutical accumulation before and after revascularization in the lateral walls of the left ventricle and right ventricle. All studies were performed using the original Cardiac Functional Imaging medical program in order to obtain quantitative information about the myocardial function of both the left ventricle, and also the right ventricle. This program made it possible to highlight the right ventricle area even in the case of its weak visualization through the initial formation of parametric images, where the right ventricle area was visualized. Results. When comparing the revascularization results of the two groups, we noted that the left ventricle ejection fraction increased significantly only in patients without initial visualization of the right ventricular myocardium. Left ventricle ejection fraction did not change after revascularization in patients with initially increased accumulation of the radiopharmaceutical in the right ventricle. Globally, only an improvement in the diastolic function of the left and right ventricles was noted in the latter group of patients. In addition, an increase in the right ventricular uptake level was noted for patients with focal cardiosclerosis and the initially increased uptake in the right ventricle after the maximum possible complete myocardial revascularization, which may indicate a redistribution of perfusion in favor of a more intact right ventricular myocardium. Conclusions. 1. In patients without signs of increased visualization of the right ventricle (group 1) after revascularization, we revealed a statistically significant increase in the left ventricle ejection fraction (p-value=0.024), a decrease in the end-systolic volume (p-value=0.024), an increase in the motion in segments corresponding to the peri-infarct scar zone (p-value=0.016), and a change in systolic thickening in the segment of the basal parts of the anterolateral wall (p-value=0.046). 2. Initially increased visualization of the right ventricle in patients with extensive focal cardiosclerosis in the myocardium of the left ventricle suggests the absence of the left ventricle ejection fraction increase after myocardial revascularization. 3. An increase in the visualization of the right ventricle after complete myocardial revascularization indicates an intersystemic redistribution of perfusion in favor of the preserved myocardium of this part of the heart.

Substantiation of the optimal mining sequence of an ore deposit under conditions of high stress and low rock mass strength

Introduction. When choosing the mining sequences of an ore deposit, technological and organizational factors are mostly taken into account. However, when using systems with caving which involve considerable mined-out spaces, the geomechanical factor, which determines stability of mine workings, plays a determining role. The research objective is to reveal the dependence between the stability of the development and face-entry headings within the mined-out space influence zone and the excavation sequence of the isolated ore block under conditions of high stress and low ore and rock mass strength. Methods of research. Numerical modeling of the enclosing ore and rock mass secondary stressstrain state formation was carried out by the finite element method in the Rocscience RS3 program together with the original FEM software package. Modeling was performed for two variants of block excavation – from the center to the flanks and from one flank to the other along the strike. For the analysis, we proposed a coefficient representing the product of compressive stress concentration zones length by their existence duration. Results. Based on the analysis of the maximum stress concentration areas distribution in the marginal rock mass, as well as the time of their influence, the optimal sequence of actual mining was substantiated according to the factor of influence on bottom workings stress-strain state – from flank to flank along the strike. Conclusions. The obtained result confirms the model representations about the mechanism of rock mass stressed redistribution in the process of lens-shaped deposit excavation. The representations suggest that during mined-out space development along the strike, compressive stresses concentrate at its ends. However, the intensity of end sections expansion in the flank to flank variant is two times as high as in the center to flank variant. The duration of the stress concentration zones impact on the bottom workings is therefore less, which is indicated by the proposed coefficient.