Degree Of Homogeneity Research Articles

CO2 adsorption-deformation-percolation characteristics of coals with different degrees of metamorphism and improvement of dynamic prediction model

The deformation and permeability changes occurring during CO2 adsorption in the coal body are important factors affecting CO2 injectability. In order to reveal the characteristic laws of adsorption, deformation and permeability of coal in the process of CO2 adsorption by different coal rank coals, the test experiments of adsorption, deformation and permeability of different coal rank coals under the condition of constant external force were carried out. The adsorption capacity of different coal samples for CO2 was obtained as anthracite > coking coal > long flame coal; The radial deformation ɛ2 and axial deformation ɛ1 of coal after CO2 gas adsorption by anthracite are the closest (ɛ2/ɛ1 is about 1.37), coking coal is the second (ɛ2/ɛ1 is about 1.73), long-flame coal is the largest (ɛ2/ɛ1 is about 2.72), In other words, the higher the coal rank, the more significant the degree of internal homogeneity and isotropy of the coal body, and the mean value of the volume deformation of CO2 adsorbed by long-flame coal is 1.07 and 1.17 times higher than that of coking coal and anthracite. The permeability curves of CO2 adsorption in all three coal samples decreased first and then increased, and the permeability of CO2 in coking coal was the largest, and the sensitivity coefficient of CO2 permeability in coal to adsorption pressure showed a trend of rapid decrease and then small increase. Based on the CO2 adsorption-deformation-percolation variation law of coal, an improved dynamic prediction model of adsorption (fitting accuracy 0.9850 ∼ 0.9963), an improved dynamic prediction model of coal body deformation (fitting accuracy 0.9889 ∼ 0.9921) and an improved dynamic prediction model of permeability (fitting accuracy 0.9848 ∼ 0.9914).

A Holocene sequence from Walufeni Cave, Southern Highlands Province, and its implications for the settlement of the Great Papuan Plateau, Papua New Guinea

This paper presents preliminary results from the 2019 excavations at Walufeni Cave, at the eastern end of the Great Papuan Plateau (GPP) in western Papua New Guinea. Preliminary dating and analysis of the unfinished excavations at Walufeni Cave span the Holocene and probably continue into the Late Pleistocene, confirming the presence of people on the Plateau from at least the Early Holocene and potentially much earlier. The data presented here offer a site-specific model of early intensive site use from at least 10,000 years ago, then ephemeral use, followed by a sustained Late Holocene occupation. Although there are significant changes in the quantity of material discard over time, there is little evidence for significant change in the subsistence base or technology, reflecting a degree of relative homogeneity until the Late Holocene, when we see the introduction of pig, a change of focus in the plant economy and the presence of marine shell from the southern coast.

Homogeneity for control systems in discrete time

Homogeneity, as a generalization of linearity to nonlinear systems, has proven to be a very powerful in systems and control. Nevertheless, only recently a notion of homogeneity was proposed for discrete-time control systems. However, this so-called D-Homogeneity directly couples the stability behaviour with the degree of homogeneity—in contrast to the continuous-time case. As an alternative, we propose the notion of S-Homogeneity, which avoids this coupling. S-Homogeneity uses a state-dependent time step that is compatible with sampling and discretization in time. We show that this concept preserves a contraction property and null-controllability for state-dependent sampling. For fixed sampling time, it yields (practical/semi-global) null controllability for sufficiently fast sampling, depending on the degree of homogeneity.

Effect of Fillers on Mechanical, Thermal Properties and Combustion Resistance of Polyurethane Foam

In this study, the mechanical and combustion properties of a polyurethane polymer were investigated as a function of the weight ratio of palm frond ash with a particle volume less than or equal to (125 μm). Several variables were investigated, including elongation, tensile strength, Young’s modulus, compressive strength, and rate of burning duration. The obtained results revealed that adding palm frond ash reduces the spaces between the polymeric chains, which reflect the polymer’s high ability to withstand the stress imposed on it, that the degree of homogeneity between each of the polymers and fillings is high. Results showed that adding 60% palm frond ash powder to the hardness combination resulted in an improvement of approximately (3.78 MPa). Moreover, the percentage 65% was recorded as the greatest value of the compressive strength of the polymer with the additive. Young’s modulus also best value is (1.71 MPa) at a ratio of 60%.

Effect of Al and Ti addition on the characteristics of oxide inclusions in Ni-based superalloy

The characteristics of inclusions have a significant influence on the performance and fatigue life of Ni-based alloy and some cracks usually initiate and propagate from inclusions. High-temperature experiments were carried out at 1823 K to study the effect of Al and Ti addition on the characteristics of oxide inclusions in Ni-based alloy. The size, number, distance, distribution of oxide inclusions and degree of homogeneity in inclusion dispersion in Ni-based alloy with [%Al]i = 0.3–0.7 and [%Ti]i = 0.7–1.2 (i represent initial addition of deoxidant) were analyzed systematically. It is found that the oxide inclusions in alloys with [%Al]i = 0.7, [%Ti]i = 0.7/1.2 had smaller average size of 2.4 µm and distributed more homogeneously. The Ostwald ripening theory and collision model were applied to point out the relationships among compositions of Ni-based alloy, behaviors of oxide inclusions and their characteristics under the condition of no external stirring. The calculated results were in good agreement with experimental results. The mechanism on obtaining fine and dispersed oxide inclusions in Ni-based alloy was summarized.

Versatile synthesis of nano-icosapods via cation exchange for effective photocatalytic conversion of biomass-relevant alcohols.

Branched metal chalcogenide nanostructures with well-defined composition and configuration are appealing photocatalysts for solar-driven organic transformations. However, precise design and controlled synthesis of such nanostructures still remain a great challenge. Herein, we report the construction of a variety of highly symmetrical metal sulfides and heterostructured icosapods based on them, in which twenty branches were radially grown in spatially ordered arrangement, with a high degree of structure homogeneity. Impressively, the as-obtained CdS-PdxS icosapods manifest a significantly improved photocatalytic activity for the selective oxidation of biomass-relevant alcohols into corresponding aldehydes coupled with H2 evolution under visible-light irradiation (>420 nm), and the apparent quantum yield of the benzyl alcohol reforming can be achieved as high as 31.4% at 420 nm. The photoreforming process over the CdS-PdxS icosapods is found to be directly triggered by the photogenerated electrons and holes without participation of radicals. The enhanced photocatalytic performance is attributed to the fast charge separation and abundant active sites originating from the well-defined configuration and spatial organization of the components in the branched heterostructures.

Иерархические структуры национальных экономических пространств: общее и частное

The paper explores the structures of interregional economic interactions of two countries, Japan and China, that are different in terms of the scale of physical space and, accordingly, the density of economic activity. The methodological feature of the conducted cross-country study is the focus on the question of how far we can get starting from the position ‘all objects are unique’. The assumption of the existence of functional hierarchies is tested for the national economic spaces under consideration; the backbone of spatial economic interactions that form commodity markets homogeneous in terms of locational characteristics of supply and demand are constructed; system effects generated by the established structures of interactions are determined. As part of the search for evidence of the existence of functional hierarchies, real interregional balances are compared with theoretical balances built in accordance with the assumptions of the models of successively inclusive hierarchy of W. Christaller (without counter commodity flows between hierarchical levels) and A. Losch’s economic landscape (taking into account counter commodity flows between hierarchical levels). For comparison purposes, the centrality coefficient is used, the critical value of which in W. Christaller’s model is 100%, whereas in A. Losch’s model it is about 40%. The parameters of the existing functional hierarchies (mainly, the degree of homogeneity of national economic spaces with respect to interregional links and the ‘list’ of central functions) are determined using the method of dyadic factor analysis, and the system effects at different hierarchical levels – using the method of localized division of composite blocks of multipliers of interregional balances. The study has shown that the properties of economic spaces, indeed, depend on the parameters of physical spaces, but the degree of similarity of the structures of interregional interactions in countries with different parameters of physical spaces is not zero. In particular, the estimates indicate the existence of functional hierarchy in both Japan and China (the centrality coefficient in the two cases is about 40%), general multiplicative effects and the degree of self-sufficiency of the regions of the highest levels of functional hierarchies in Japan and China are comparable, whereas the values of system effects absorbed by these regions are different

Homogenization of unsaturated bentonite during hydration

Bentonite barriers are a key component in may designs of deep geological repositories for high level nuclear waste. During the hydration stage, the bentonite undergoes non-uniform changes in dry density that may persist even after reaching a fully saturated state. Since dry density controls the properties of the bentonite that ensure the functions of safety of the barrier, the potential of bentonite for homogenization or otherwise is a matter of high relevance. The paper presents the results and the analyses of two hydration tests on initially heterogenous samples, especially designed to explore the phenomena and processes underlying the homogenisation of bentonite materials. The formulation and constitutive model used in the analyses are briefly presented followed by a description of the tests. Subsequently, the experimental dataobtained from the tests are discussed together with the results of the hydromechanical analyses performed. Particular attention is given to the degree of homogenization of the specimens achieved at the end of the tests. The simulations have resulted in a very satisfactory agreement with test observations, especially egarding the final state of the samples, thus enhancing the confidence in the numerical tool employed.

Quantitative electrical homogeneity assessment of nanowire transparent electrodes.

The homogeneous distribution of electric current (electrical homogeneity) is not guaranteed in nanowire electrodes but is crucial for the stability of the electrode and actually desirable in most applications. Despite the relevance of this feature, it is common practice to perform qualitative assessments at the electrode scale, thus masking local effects. To address this issue, we have developed a computational strategy to aid in the design of nanowire electrodes with improved electrical homogeneity. Nanowire electrodes are modeled as two-dimensional networks of stick and junction resistors (with resistance Rw and Rj, respectively) to simulate the electric conduction process. Electrodes are discretized into regular grids of squares and the electrical power of the network contained in each square is computed. The mismatch between the areal power density of the entire electrode and that of the squares provides a quantitative electrical homogeneity evaluation. Repeating the analysis with squares of different size yields an evaluation that spans across length scales. A scalar indicator, coined the homogeneity index, summarizes the results of the multiscale evaluation. The proposed strategy is employed to assess the electrical homogeneity of silver nanowire electrodes through the analysis of scanning electron microscopy images. Our results agree with the outcomes of the experimental assessment performed on the same electrodes. Parametric studies are performed by varying nanowire content and nanowire-to-junction resistance ratio Rw/Rj. We observe that a significant reduction of contact resistance is not necessary to ensure a high degree of homogeneity. The ideal condition of negligible junction resistance (Rw ≫ Rj) leads to the best-case scenario, a situation which is closely approached if Rw ≈ Rj (15% difference at the most in terms of homogeneity index).

A study of role of games and sports in national integration and international understanding

National integration is not a simple issue rather it is a slow and steady process. It will remain a dream and distinct goal to achieve National integration unless concrete steps are taken to foster it. The rise and fall of a nation depends upon the extent of the development of a feeling of nationalism in its citizens. Hence this feeling needs to be nurtured, cultivated and strengthened by all possible ways and means. In modern society it seems that sport is one of the most important and effective means to achieve this great task. As India is a big country the inhabitants of which belong to various communities and groups. The cultural patterns of all these communities and groups are different. It is obvious to have different ideals, values, customs traditions, ways of living, eating and dressing in different communities and groups. This is true that India represents a wide variety of peoples. There was no time when one language was spoken throughout the country never was the time when all the Indians followed any one religion these diversity is often lead to mutual tension and then unfortunately towards National disintegration. Strength of the nation depends on the degree of homogeneity of its people which again depends upon the acceptance of common standards and values. Therefore, the need and importance of National integration cannot be over emphasized. The scope of sport is very vast it includes all those activities and experiences which prepare the individual to engage himself for his own good and for good of the society of which he is an integral part. Participation in sport create a climate that would help to create feelings of oneness. It acts as anti dote to separatistic and divisive forces. It broadens the outlook, fosters a feeling of togetherness and nationalism and a spirit of sacrifice and tolerance so that the narrow group interest are submerged in a larger interest of the community. It also includes a feeling of love and regard for the history, culture, religion, language and traditions of the nation. Therefore, importance of participation in games and sports and it's role in promotion of national integration and international understanding needs to be analysed. The present paper is focused upon to have an analytical study of how participation in games and sports could be instrumental in promoting National integration among its citizens. Aim: The principal aim of this paper is to highlight the role of games and sports in promoting national integration and international understanding.

Исследование отношения между музыкальной вовлеченностью, интеллектом и успешностью обучения у студентов с разной профессиональной специализацией

We investigated the relationship between music engagement, academic success and intelligence in non-musical students (N = 136). Currently, there is a lack of understanding to the extent in which individual leisure interests and extracurricular engagement influence academic success in different subject areas, as well as the relationship between fluid intelligence and crystallized experience. Clarifying these questions we formed the aim of this study. To diagnose musical engagement and intelligence we used the approved psychometric techniques - Gold-MSI v1.0 “Active engagement” scale, Raven's test, Amthauer's test. We checked the assumptions that musical engagement influences the strength of the correlation between fluid and crystallized intelligence and that the relationship between musical engagement and academic success is determined by the level of fluid intelligence on the one hand, and the degree of homogeneity of the subject areas of engagement on the other. The results of the study showed that musical engagement may play a significant role in predicting the academic performance of non-musicians as well as in the development of crystallized experience. The hypothesis that musical engagement, being a non-relevant behavioral activity in relation to general educational experience and competence, contributes to a decrease in the strength of the link between fluid and crystallized intelligence was confirmed. The other hypothesis was partially confirmed, as it was found that the relationship between musical engagement and academic success is mediated by the fluid intelligence factor, but this mediation is specific to groups with different professional skills. There is a non-linear relationship in the humanities group: the best learning performance is achieved by students with intermediate levels of engagement. In the group of "precise" occupations, the relationship between the variables is linear and negative. The findings are interpreted in terms of modern models of intelligence and subjectoriented knowledge models. The results contribute to improving the quality of prediction of learning success and professional realization, and contribute to elucidating the psychological mechanisms of engagement.

Basic Psychological Need Frustration and Work Engagement of Employees in Andres Bonifacio College, Inc.

This study aimed to determine the basic psychological need for frustration and how it affects the work engagement of Andres Bonifacio College, Inc. employees during the school year 2022-2023. A quantitative descriptive-correlational research design was employed in this study. Using frequency counting and percent, weighted mean, standard deviation, Mann-Whitney U test, Kruskal-Wallis test, and Spearman Rank-Order Correlation, data were obtained from 120 employees of Andres Bonifacio College, Inc. The study discovered that the respondents' perceived level of basic psychological need frustration is not Frustrated. Standard deviations less than 3.0 supported a high degree of homogeneity in their responses. Moreover, the study found that the respondents perceived level of work engagement is highly engaged. The study found a significant difference in the perceived level of basic psychological need frustration when the respondents were grouped in age, position, and educational attainment. However, there is no significant difference in the perceived level of basic psychological need frustration when the respondents are grouped in terms of sex, monthly income, and years of service. Furthermore, there is no significant relationship between basic psychological needs, frustration, and work engagement. This indicates that the basic psychological need frustration was not significantly related to employees' work engagement in Andres Bonifacio College, Inc. Hence, management strategy and working environments would be enhanced to boost employee job satisfaction, psychological well-being, and engagement.

Золь-гель синтез нанодисперсных твердых растворов на основе гексаферрита бария состава SrXBa(1–Х)Fe12O19

The present paper provides data on the sol-gel synthesis of M-ferrite with the SrxBa(1–x)Fe12O19 (х = 0; 0.3; 0.5; 0.7; 1) composition. The synthesis technique is based on the preparation of a polymeric citrate complex from citric acid and nitrates of barium, strontium, and iron, its calcination at 500 °C followed by mechanochemical activation, and calcination at 700 °C. The target product is a dark brown powder, which has been studied by the XRD and SEM methods, energy-dispersive X-ray spectroscopy and differential scanning calorimetry (DSC). The single-phase state of the obtained samples is confirmed by powder X-ray diffraction. The X-ray patterns of the synthesized hexaferrites match the X-ray patterns of reference com-pounds from the ICDD database for all diffraction maxima. The unit cell parameters of the samples have been calculated from the X-ray diffraction patterns. They linearly depend on the degree of barium substitution in hexaferrite, that is, the successful replacement of barium ions in the crystal lattice by strontium ions, due to the Vegard rule for solid solutions. Morphological pa-rameters have been studied using SEM, the analysis of the obtained images indicates the for-mation of nanodispersed hexaferrites, for which the average particle size is 50 nm. The average particle size, calculated by the Scherrer's formula, equals 25 nm. The usual hexagonal form of hexaferrite particles has not been observed in the SEM images due to the small particle size. En-ergy-dispersive X-ray spectroscopy of the obtained images indicates a high degree of homogeni-zation for the chosen synthesis technique. Using the DSC method we obtained values of Curie temperature which show it’s increases linearly with an increasing of Sr weight percent

On m-point homogeneous polytopes in euclidean spaces

This paper is devoted to the study the m-point homogeneity property and the point homogeneity degree for finite metric spaces. Since the vertex sets of regular polytopes, as well as of some their generalizations, are homogeneous, we pay much attention to the study of the homogeneity properties of the vertex sets of polytopes in Euclidean spaces. Among main results, there is a classification of polyhedra with all edges of equal length and with 2-point homogeneous vertex sets. In addition, a significant part of the paper is devoted to the development of methods and tools for studying the relevant objects.

Influence of the degree of mixing on the qual-ity of preparation of coal batches

The low degree of mixing is due to the large quantity of components in the of the batch, irregular supply of coal concentrates, fluctuations in their physical and chemical parameters. Research results indicate that increasing the homogeneity of the coal batch through the introduction of organized mixing will improve the physical and mechanical properties of coke. It should be noted that the smallest effect from the use of mixing units is achieved with the batch preparation scheme, which involves grinding all its components in one crushing unit. At the same time, the use one crusher instead two or four makes it possible to achieve a high degree of homogeneity of the batch. In the final grinding schemes, which provide for group or differentiated grinding the components of batch is required to use mixing machines. To ensure the efficiency mixing the components of the coal batch, it is desirable to install mixers in the transfer nodes, on the transfer of the batch from the conveyor to the conveyor or on top of the coal tower, in this case the segregation of the batch is reduced to a minimum. The degree of mixing all indicators of coal batch for 98-99%, which ensure a stabilization of the properties of coke in conditions multi-basin coking raw material base is one of the most important problem of the coal preparation technology for coking Based on the results of the research in terms of coke production of PJSC «ArcelorMittal Kryvyi Rih» found that the large quantity of components in the mixture, the variability of their physicochemical parameters are cause of low degree of mixing the batch. Organized mixing of the coal batch using mixing machines was recommended to implement

THE LATEST TRENDS IN THE CREATION OF IMPACT-VIBRATION EQUIPMENT WITH DIFFERENT TYPES OF DRIVES FOR SOIL PROBING

The study of soils by immersion of a cone under the influence of ultrasonography is one of the express methods of obtaining engineering and geological information about the physical and mechanical properties of the foundation from loose soils of buildings and structures. It makes it possible to detect the degree of homogeneity of probed soils; determine the position of the boundaries (contacts) of various lithological layers and bearing layers for the fuel base; to identify and delineate in plan and in depth the weakened zones on the studied areas for the exact reference of the place of conducting experimental works; choose the optimal options for choosing hammers; evaluate the physical and mechanical properties of sandy soils (density, angle of internal friction, etc.); roughly estimate the modulus of deformation of sandy soils. The main tasks are the development, research and calculation of the main parameters of installations with a hydraulic impulse drive for soil probing. The object of research is the process of soil probing. The subject of the study is the hydropulse drive of the soil probing installation. Experience has shown that the effective use of field methods is possible only under the condition of a methodically correct approach to the preparation and execution of programs of the entire complex of search operations. Various aspects of the problem of comprehensive soil research using field methods were developed and deepened gradually.The main research methods include the analysis of information on existing methods and installations for spraying tungsten powders, mathematical modeling of processes in the spindle unit of the installation for spraying metal powders, taking into account its design features and operating modes based on nonlinear differential equations of heat transfer from solid and liquid bodies using numerical methods of their solution based on the FlowVision program.

The spatial pattern and influencing factors of tourism eco-efficiency in Inner Mongolia, China.

Tourism eco-efficiency is a performance basis for evaluating green total factor productivity and sustainable development. The objective of this study was to measure tourism eco-efficiency in Inner Mongolia and explore its influencing factors. The aim was to provide an accurate reference for improving the quality and efficiency of tourism in Inner Mongolia and promoting the sustainable development of the regional economy and society. Tourism eco-efficiency in Inner Mongolia from 2009 to 2019 was calculated using a super-slacks-based measure (SBM) model with an undesirable output. The spatial variation function was used to explore the spatial evolution pattern of tourism eco-efficiency in Inner Mongolia, and the influencing factors of the spatial evolution were analyzed by geographically weighted regression. Tourism eco-efficiency in Inner Mongolia is relatively low. Eco-efficiency values among cities in Inner Mongolia vary, and their distribution is not balanced. The structural eco-efficiency of tourism in Inner Mongolia has been consistent from 2009 to 2019. The degree of homogenization in the overall direction is relatively good. Furthermore, its spatial distribution form and internal structure evolution show a certain regularity and continuity. The pattern evolution of tourism eco-efficiency in Inner Mongolia is jointly driven by the economic level, environmental regulation, industrial structure, traffic conditions, resource endowment, and tourism reception facilities. These influencing factors show obvious spatial heterogeneity. From the perspective of Inner Mongolia, the difference in the tourism eco-efficiency value from 2009 to 2019 was relatively large, but the number of effective areas in the efficiency frontier generally showed a fluctuating growth trend. The range parameters of tourism eco-efficiency showed a decreasing trend, and the spatial correlation effect of tourism eco-efficiency in Inner Mongolia showed a decreasing trend under the influence of structural and spatial differentiation.

Study the effect of adding olefin powder extracted on the mechanical properties of low density of polyethylene (LDPE)

The Study of the Effect of oyster from the Caspian Sea on the Mechanical properties of low density polyethylene (LDPE), which is manufactured in the General state company of petrochemical industries, Basra, as function of the percentages of oysters extracted from the Caspian Sea in Iran (0%, 1%, 2%, 3%, 4%, 5% ), at particular size. ( 250 m) were investigated through several variables, such as strength, and elongation. The obtained results were appeared that the added oyster act to reduce the spaces between the polymer chains, which reflects the high ability of the polymer against the applied stress, and a high degree of homogeneity between the host polymer and the added fillers, and this increase will give further property that increase the hardness of theprepared specimens, the results lead to that the strength at both break will be affected little till the percentage (2%) which reflects the increase in the ductile of the polymer grafted with oyster and wide range of the application for this polymer .

The application of the EQCM data analysis for the examination of surface oxide formation on Pt-Pd-Ru ternary alloys

The stoichiometry of surface oxides, formed on Pt-Pd-Ru alloys in 0.5 M H2SO4 aqueous solutions, was postulated on the basis of cyclic voltammetric (CV) and the electrochemical quartz crystal microbalance (EQCM) measurements. A procedure of data analysis was elaborated to extract the information on surface oxide properties from the correlations between the EQCM frequency changes and electric charge. The average values of metal oxidation state in the oxides depend on potential of their formation, alloy composition and degree of alloy homogeneity. The highest metal oxidation state (+8) was reached for 10 %Pt-25 %Pd-65 % Ru alloy, while the lowest one (+4) for 35 %Pt-26 %Pd-38 %Ru alloy. Preliminary hydrogen electrosorption on Pd-rich (63 %) or Ru-rich (65 %) Pt-Pd-Ru alloys resulted in a decrease in the average metal oxidation states in surface oxides, whereas for other alloys the influence of hydrogen treatment was negligible.

Stability Analysis for Hybrid Time-Delay Systems With Double Degrees

In this article, the problem of stability is investigated for a class of hybrid time-delay systems with double degrees. The systems consist of both discrete and continuous subsystems that have homogeneity and nonzero degrees. Conditions are derived to guarantee the preasymptotic stability of the systems. The relationships of solutions are established between the systems with different sizes using homogeneous properties. Then, equivalent conditions are presented for the analysis of preasymptotic stability. Furthermore, necessary and sufficient delay-independent conditions are developed to analyze the stability of the systems. Finally, two examples are provided to illustrate the effectiveness of the proposed new stability analysis methods.