Density Of Medium Research Articles

Augmented CO2 utilization for acidic industrial-level CO2 electroreduction to near-unity CO

Electrochemical reduction of CO2 represents an environmental-friendly process that could alleviate the environmental and energy crisis by eliminating greenhouse gasses and generating value-added chemicals. However, industrial-level CO2 reduction to CO suffers from low CO2-conversion efficiency. To address this issue, this work proposes to use acidic electrolytes to avoid carbonate/bicarbonate salt precipitation, and shell for local CO2 adsorption to improve its utilization and thus facilitate electroconversion. An Ag-based metal-organic framework (MOF) is hybridized with Ag, which exhibits near-unity selectivity to CO at an industrial-level current density (500 mA cm−2) in acidic media, robust electrochemical stability (100 h) and more importantly, high CO2 conversion efficiency of 42.5 %. Fundamentally, CO2 molecules are activated by Ag-MOF via atop adsorption of *CO after uptake by the porous organic complexes. The extraordinary performance originates from multi-scale regulation of CO2 transport from the gas-diffusion layer to the local CO2 adsorption shell near the atomic Ag active center of Ag-MOF.

Изучение биологических и функциональных свойств микроорганизмов с высокой устойчивостью к марганцу (II)

The issue of water treatment of the central water supply, as well as wastewater, from excessive content of heavy metals (HMs) remains relevant at the present time. The presence of heavy metals, even in trace amounts, has a negative impact not only on the environment, but also on all human organic systems. At the moment, iron and manganese are among the main pollutants entering the human body via drinking water. Studies were carried out on the biological and functional properties of microorganisms isolated from highly magnetic soil, which previously demonstrated high resistance to manganese (II). Microbial strains with maximum resistance to Mn (II) were identified as: Bacillus simplex 55.2, B. simplex 13.2 and Listeria murrayi 13.4. The growth dynamics of B. simplex 55.2 and B. megaterium 69.5 was studied under conditions of periodic cultivation in a liquid medium containing 2 mmol/L Mn (II). It was shown that after 7 day’s cultivation, the weight of the biomass of B. megaterium 69.5 increased by 5.5 times, B. simplex 55.2 increased by 3.7 times relative to the values after 1 day cultivation, the optical density of the culture medium B. megaterium 69.5 increased 4 times, B. simplex 55.2 increased 2 times compared with the initial sowing dose. The specific growth rate of B. megaterium 69.5 after 7 days cultivation was higher than that of B. simplex 55.2 by about 2 times, and the degree of removal of Mn (II) from the aquatic environment was less. B. simplex 55.2 reduced the content of Mn (II) by 66%, B. megaterium 69.5 reduced by 50%. It was established that B. megaterium 69.5, B. simplex 55.2, B. simplex 13.2 and L. murrayi 13.4 are able to grow in conditions of high alkalinity and mineralization of the medium (pH 7–10; 10% NaCl). Taking into account that these microorganisms are able to remove high concentrations of Mn (II) from the aquatic environment, they are promising for their use in water treatment biotechnology.

Exploring factors influencing domestic violence: a comprehensive study on intrafamily dynamics.

This econometric analysis investigates the nexus between household factors and domestic violence. By considering diverse variables encompassing mood, depression, health consciousness, social media engagement, household chores, density, and religious affiliation, the study aims to comprehend the underlying dynamics influencing domestic violence. Employing econometric techniques, this study examined a range of household-related variables for their potential associations with levels of violence within households. Data on mood, depression, health consciousness, social media usage, household chores, density, and religious affiliation were collected and subjected to rigorous statistical analysis. The findings of this study unveil notable relationships between the aforementioned variables and levels of violence within households. Positive mood emerges as a mitigating factor, displaying a negative correlation with violence. Conversely, depression positively correlates with violence, indicating an elevated propensity for conflict. Increased health consciousness is linked with diminished violence, while engagement with social media demonstrates a moderating influence. Reduction in the time allocated to household chores corresponds with lower violence levels. Household density, however, exhibits a positive association with violence. The effects of religious affiliation on violence manifest diversely, contingent upon household position and gender. The outcomes of this research offer critical insights for policymakers and practitioners working on formulating strategies for preventing and intervening in instances of domestic violence. The findings emphasize the importance of considering various household factors when designing effective interventions. Strategies to bolster positive mood, alleviate depression, encourage health consciousness, and regulate social media use could potentially contribute to reducing domestic violence. Additionally, the nuanced role of religious affiliation underscores the need for tailored approaches based on household dynamics, positioning, and gender.

Gas phase Elemental abundances in Molecular cloudS (GEMS)

Context. Carbon monosulphide (CS) is among the few sulphur-bearing species that have been widely observed in all environments, including in the most extreme, such as diffuse clouds. Moreover, CS has been widely used as a tracer of the gas density in the interstellar medium in our Galaxy and external galaxies. Therefore, a complete understanding of its chemistry in all environments is of paramount importance for the study of interstellar matter. Aims. Our group is revising the rates of the main formation and destruction mechanisms of CS. In particular, we focus on those involving open-shell species for which the classical capture model might not be sufficiently accurate. In this paper, we revise the rates of reactions CH + S → CS + H and C2 + S → CS + C. These reactions are important CS formation routes in some environments such as dark and diffuse warm gas. Methods. We performed ab initio calculations to characterize the main features of all the electronic states correlating to the open shell reactants. For CH+S, we calculated the full potential energy surfaces (PESs) for the lowest doublet states and the reaction rate constant with a quasi-classical method. For C2+S, the reaction can only take place through the three lower triplet states, which all present deep insertion wells. A detailed study of the long-range interactions for these triplet states allowed us to apply a statistic adiabatic method to determine the rate constants. Results. Our detailed theoretical study of the CH + S → CS + H reaction shows that its rate is nearly independent of the temperature in a range of 10–500 K, with an almost constant value of 5.5 × 10−11 cm3 s−1 at temperatures above 100 K. This is a factor of about 2–3 lower than the value obtained with the capture model. The rate of the reaction C2 + S → CS + C does depend on the temperature, and takes values close to 2.0 × 10−10 cm3 s−1 at low temperatures, which increase to ~ 5.0 × 10−10 cm3 s−1 for temperatures higher than 200 K. In this case, our detailed modeling - taking into account the electronic and spin states – provides a rate that is higher than the one currently used by factor of approximately 2. Conclusions. These reactions were selected based on their inclusion of open-shell species with many degenerate electronic states, and, unexpectedly, the results obtained in the present detailed calculations provide values that differ by a factor of about 2–3 from the simpler classical capture method. We updated the sulphur network with these new rates and compare our results in the prototypical case of TMC1 (CP). We find a reasonable agreement between model predictions and observations with a sulphur depletion factor of 20 relative to the sulphur cosmic abundance. However, it is not possible to fit the abundances of all sulphur-bearing molecules better than a factor of 10 at the same chemical time.

Determining the features of histograms of dangerous parameters of the gas environment in the absence and occurrence of fire

The object of research is histograms of the dynamics of dangerous parameters of the gas environment, the values of which are measured in real time at the intervals of absence and ignition of materials. The method of determining histograms during a typical selection of measurements is described. This method allows one to determine histograms for samples of an arbitrary position and the size of the data interval of measurements of the dynamics of dangerous parameters of the gas environment. On the basis of histograms on the intervals of the absence and occurrence of fires of test materials, indicators of their summary statistics can be determined. Laboratory experiments were conducted to study the features of the histograms of carbon monoxide concentration, smoke density, and temperature of the gas medium for intervals of reliable absence and appearance of ignition of materials in the form of alcohol and textiles. The results of the analysis of the histograms clearly show that the dynamics of the studied dangerous parameters at the indicated intervals differ from the Gaussian. At the same time, the histograms differ in shape, which depends on the type of ignition material and the corresponding dangerous parameter. Based on the features of the histograms of the dynamics of dangerous parameters on the intervals of the absence and appearance of fires of test materials, the simplest indicators of summary statistics in the form of the range, number, and position of the modes are determined. It was established that when alcohol ignites, the variation range of carbon monoxide concentration, smoke density, and gas temperature increases from 0.545, 0.068, and 0.161 to 7.121, 0.523, and 8.71, respectively. At the same time, the range of variation of these parameters during textile ignition increases from 0.182, 0.205, and 0.323 to 0.394, 0.386, and 2.903, respectively. The obtained results in aggregate or one by one can be used in practice for early detection of fires in order to prevent the occurrence of fires in premises

Acoustophoretic Characterization and Separation of Blood Cells in Acoustic Impedance Gradients.

Single-cell phenotyping based on biophysical properties is a promising tool to distinguish cell types and their response to a given condition, and charting such properties also enables optimization of cell separations. Isoacoustic focusing, where cells migrate to their points of zero acoustic contrast in an acoustic impedance gradient, added the effective acoustic impedance of cells to the directory of biophysical properties that can be utilized to categorize or separate cells. This study investigates isoacoustic focusing in a stop-flow regime and shows how cells migrate towards their isoacoustic point. We introduce a numerical model that we use to estimate the acoustic energy density in acoustic impedance gradient media by tracking particles of known properties, and we investigate the effect of acoustic streaming. From the measured trajectories of cells combined with fluorescence intensity images of the slowly diffusing gradient, we read out the effective acoustic impedance of neutrophils and K562 cancer cells. Finally, we propose suitable acoustic impedance gradients that lead to a high degree separation of neutrophils and K562 cells in a continuous-flow configuration.

Acidic Hydrogen Evolution Electrocatalysis at High-Entropy Alloys Correlates with its Composition-Dependent Potential of Zero Charge.

The vast possibilities in the elemental combinations of high-entropy alloys (HEAs) make it essential to discover activity descriptors for establishing rational electrocatalyst design principles. Despite the increasing attention on the potential of zero charge (PZC) of hydrogen evolution reaction (HER) electrocatalyst, neither the PZC of HEAs nor the impact of the PZC on the HER activity at HEAs has been described. Here, we use scanning electrochemical cell microscopy (SECCM) to determine the PZC and the HER activities of various elemental compositions of a Pt-Pd-Ru-Ir-Ag thin-film HEA materials library (HEA-ML) with high statistical reliability. Interestingly, the PZC of Pt-Pd-Ru-Ir-Ag is linearly correlated with its composition-weighted average work function. The HER current density in acidic media positively correlates with the PZC, which can be explained by the preconcentration of H+ in the electrical double layer at potentials negative of the PZC.

Die Elektrokatalyse der Wasserstoffentwicklung im Sauren an Hochentropielegierungen korreliert mit dem von der Zusammensetzung abhängigen Nullladungspotential

AbstractAufgrund der enormen Variation möglicher Elementkombinationen von Hochentropielegierungen (HEAs) ist es von entscheidender Bedeutung, Aktivitätsdeskriptoren zu finden, um rationale Prinzipien für die Entwicklung von Elektrokatalysatoren zu entwickeln. Trotz der zunehmenden Beachtung des Nullladungspotentials (PZC) bei Elektrokatalysatoren für die Wasserstoffevolutionsreaktion (HER), wurden weder das PZC von HEAs noch die Auswirkungen des PZC auf die HER‐Aktivität bei HEAs beschrieben. Hier verwenden wir die rasterelektrochemische Zellmikroskopie (SECCM), um das PZC und die HER‐Aktivitäten verschiedener Elementzusammensetzungen einer Pt−Pd−Ru−Ir−Ag‐Dünnfilm‐HEA‐Materialbibliothek (HEA‐ML) mit hoher statistischer Zuverlässigkeit zu bestimmen. Interessanterweise ist das PZC von Pt−Pd−Ru−Ir−Ag linear mit seiner zusammensetzungsgewichteten durchschnittlichen Austrittsarbeit korreliert. Die HER‐Stromdichte in sauren Medien korreliert positiv mit dem PZC, was durch die Anreicherung von H+ in der elektrochemischen Doppelschicht bei negativen Potentialen relativ zum PZC erklärt werden kann.

Evidence for Modification of b Quark Hadronization in High-Multiplicity pp Collisions at sqrt[s]=13 TeV.

The production rate of B_{s}^{0} mesons relative to B^{0} mesons is measured by the LHCb experiment in pp collisions at a center-of-mass energy sqrt[s]=13 TeV over the forward rapidity interval 2<y<4.5 as a function of the charged particle multiplicity measured in the event. Evidence at the 3.4σ level is found for an increase of the ratio of B_{s}^{0} to B^{0} cross sections with multiplicity at transverse momenta below 6 GeV/c, with no significant multiplicity dependence at higher transverse momentum. Comparison with data from e^{+}e^{-} collisions implies that the density of the hadronic medium may affect the production rates of B mesons. This is qualitatively consistent with the emergence of quark coalescence as an additional hadronization mechanism in high-multiplicity collisions.

Granular flow experiment using artificial gravity generator at International Space Station

Studying the gravity-dependent characteristics of regolith, fine-grained granular media covering extra-terrestrial bodies is essential for the reliable design and analysis of landers and rovers for space exploration. In this study, we propose an experimental approach to examine a granular flow under stable artificial gravity conditions for a long duration generated by a centrifuge at the International Space Station. We also perform a discrete element simulation of the granular flow in both artificial and natural gravity environments. The simulation results verify that the granular flows in artificial and natural gravity are consistent. Further, regression analysis of the experimental results reveals that the mass flow rate of granular flow quantitatively follows a well-known physics-based law with some deviations under low-gravity conditions, implying that the bulk density of the granular media decreases with gravity. This insight also indicates that the bulk density considered in simulation studies of space probes under low-gravity conditions needs to be tuned for their reliable design and analysis.

Leaf resistance to Botrytis cinerea in wild tomato Solanum habrochaites depends on inoculum composition.

Tomato (Solanum lycopersicum) cv. Moneymaker (MM) is very susceptible to the grey mould Botrytis cinerea, while quantitative resistance in the wild species Solanum habrochaites (accession LYC4) has been reported. In leaf inoculation assays, an effect of nutrient and spore concentration on disease incidence was observed. Resistance in LYC4 leaves was manifested as a high incidence of tiny black, dispersed spots which did not expand ("incompatible interaction") and was pronounced when B. cinerea was inoculated at high spore density (1000 spores/µL) in medium with 10 mM sucrose and 10 mM phosphate buffer. Under the same condition, a high frequency of expanding lesions was observed on MM leaves ("compatible interaction"). Remarkably, inoculation of LYC4 with a high spore density in medium with higher concentrations of sucrose and/or phosphate as well as lower spore density (30 spores/µL) in medium with low sucrose and phosphate, all resulted in a higher percentage of expanding lesions. The lesion sizes at 3 days post inoculation differed markedly between all these inoculation conditions. This inoculation method provides a convenient tool to study mechanisms that determine the distinction between compatible and incompatible interactions between B. cinerea and a host plant.

INCREASE IN THE DENSITY OF CARRIER MEDIUM AS A WAY TO CREATE HYDROTRANSPORT OF MINERALS IN LARGE LUMP FORM

Existing coal hydro-transport technologies require preliminary grinding of coal into powder. The same circumstance prevents the use of pipeline transport for the delivery of granite, limestone and other building materials from mining sites to the consumer. With an increase in the density of the carrier medium it becomes possible to supply through the pipeline coal and other solid materials in lumpy form. After the complete regeneration of the carrier medium, the delivered coal or lump material in such a water-salt liquid is no different from that transported by rail. The regenerated working liquid is completely returned to the head of the process.

RadioAstron discovery of a mini-cocoon around the restarted parsec-scale jet in 3C 84

We present RadioAstron space-based very long baseline interferometry (VLBI) observations of the nearby radio galaxy 3C 84 (NGC 1275) at the centre of the Perseus cluster. The observations were carried out during a perigee passage of the Spektr-R spacecraft on September 21–22, 2013 and involved a global array of 24 ground radio telescopes observing at 5 GHz and 22 GHz, together with the Space Radio Telescope (SRT). Furthermore, the Very Long Baseline Array (VLBA) and the phased Very Large Array (VLA) observed the source quasi-simultaneously at 15 GHz and 43 GHz. Fringes between the ground array and the SRT were detected on baseline lengths up to 8.1 times the Earth’s diameter, providing unprecedented resolution for 3C 84 at these wavelengths. We note that the corresponding fringe spacing is 125 μas at 5 GHz and 27 μas at 22 GHz. Our space-VLBI images reveal a previously unseen sub-structure inside the compact ∼1 pc long jet that was ejected about ten years earlier. In the 5 GHz image, we detected, for the first time, low-intensity emission from a cocoon-like structure around the restarted jet. Our results suggest that the increased power of the young jet is inflating a bubble of hot plasma as it carves its way through the ambient medium of the central region of the galaxy. Here, we estimate the minimum energy stored in the mini-cocoon, along with its pressure, volume, expansion speed, and the ratio of heavy particles to relativistic electrons, as well as the density of the ambient medium. About half of the energy delivered by the jet is dumped into the mini-cocoon and the quasi-spherical shape of the bubble suggests that this energy may be transferred to a significantly larger volume of the interstellar medium than what would be accomplished by the well-collimated jet on its own. The pressure of the hot mini-cocoon also provides a natural explanation for the almost cylindrical jet profile seen in the 22 GHz RadioAstron image.

Unimorph based sensor modelling and rheological assessment of fluidic media using frequency response of improved sensor design

This work presents a hassle-free rheological assessment of fluidic media using the frequency response of a self-sensing and self-actuating piezoelectric cantilever sensor. Firstly, an analytical modelling approach for a unimorph-based cantilever sensor is derived and validated. Afterwards, the sensing performance of a rectangular cantilever sensor is improved by modifying its profile to a stepped shape. Frequency response parameters of the cantilever sensors are tracked in vacuum as well as in water, glycerin and varying concentration glycerin solution. These parameters are used to develop the calibration curves for the density and viscosity assessment of the water-glycerin solutions. The calculated density and viscosity utilizing the cantilever sensors are in good agreement with the respective values given by the standard instruments. This implies that the presented sensors can be successfully used for density and viscosity measurement of range 1000–1270 kg/m3 and 12.82–41.35 cP, respectively. The presented method is capable to simultaneously estimate the density and viscosity of the fluidic media without fully immersing the sensor in that media, which can tackle many operational troubles.

The relationship between mammalian burrow abundance and bankrupt bush (Seriphium plumosum) encroachment

Background: Much of the Grassland Biome in South Africa is prone to shrub encroachment, leading to loss of ecosystem services, habitat heterogeneity and species diversity. Burrowing mammals are an important component of grasslands as these animals create microhabitats for other taxa, including smaller mammal species, birds, reptiles and invertebrates. However, our understanding of how shrub encroachment affects burrowing mammals is poor. Objectives: Here we assessed the relationship between burrow abundance and bankrupt bush, Seriphium plumosum, encroachment as well as burrowing mammal diversity in bankrupt bush encroached and non-encroached grasslands. Method: Shrub density, medium and large mammal burrow abundance and density were measured in 24 encroached and 24 non-encroached areas randomly selected in the Telperion Nature Reserve, Mpumalanga, South Africa. In addition, burrowing mammal diversity was assessed using camera traps in a subset of six encroached and six non-encroached areas. Results: Our results show that the abundance and density of medium and large burrows were significantly lower in encroached areas than in non-encroached areas (p = 0.011 and p &lt; 0.001, respectively). The relationship between burrow abundance and bankrupt bush encroachment was negative (rho = -0.456, p = 0.001). However, burrowing mammal diversity had no significant difference between encroached and non-encroached areas. Conclusion: Our data, therefore, suggest that with increasing bankrupt bush encroachment and a decreased abundance in burrowing mammal ecosystem services, a negative effect will occur on burrowing mammal communities, leading to the reduction in species-specific habitat heterogeneity and possibly animal biodiversity.

Analyses of the Effectiveness of Different Media Depths and Plant Treatments on Green Roof Rainfall Retention Capability under Various Rainfall Patterns

Green roofs have been used to reduce rainfall runoff by altering hydrological processes through plant interception and retention as well as detention within the green roof system. Green roof media depth, substrate type, plant type and density, regional climatic conditions, rainfall patterns, and roof slope all impact runoff retention. To better understand the impacts of media depth (10, 15, and 20 cm), plant (planted and non-planted), and rainfall pattern (low, medium, and high) on rainfall retention, we analyzed data collected between September 2005 and June 2008 from 24 green roof models (61 cm × 61 cm) for growing and non-growing seasons. Our results showed that a planted green roof has greater rainfall retention capability than a non-planted green roof for all media depths. Interestingly, a non-planted green roof system with a 10 cm media depth retained greater rainfall than a planted green roof during both growing and non-growing periods. Retention capability decreased with increasing rainfall amounts for both planted and non-planted green roofs and seasons (growing and non-growing). The 15 cm media depth green roof retained significantly greater rainfall depth than the 20 cm models during medium (0.64 to 2.54 cm) and high (&gt;2.54 cm) rainfall events for the growing season but not during the non-growing season. The study provides insight into the interactive effects of media depth, rainfall amount, plant presence, and seasons on green roof performance. The results will be helpful for designing economical and effective green roof systems.

Renal perfusion improvement in the perioperative period after unilateral endovascular revascularization in patients with atherosclerotic renal artery stenosis.

The clinical benefits of endovascular treatment in renal artery stenosis (RAS) remain controversial. This study used an intraoperative renal perfusion imaging technique, called flat-panel detector parenchymal blood volume imaging (FD-PBV), to observe the change in renal perfusion after endovascular treatment in RAS. In a prospective, single-center study, we assigned 30 patients with atherosclerotic RAS who underwent endovascular treatment between March 2016 and March 2021. The preoperative and postoperative results of renal perfusion, blood pressure, and renal function, were compared. Both median kidney volume (p < 0.001) and median preoperative mean density of contrast medium (MDCM) (p = 0.028) increased significantly after endovascular treatment. The ratio of postoperative and preoperative MDCM differed greatly among the patients. For patients with preoperative MDCM <304.0 HU (Subgroup A, 15 cases), MDCM significantly increased after treatment (p = 0.001) and 12 (80.0%) patients had more than 10% increase in renal perfusion. For patients who had relatively high preoperative renal perfusion (MDCM ≥304.0 HU, Subgroup B, 15 cases), preoperative and postoperative MDCM were similar (p = 0.776). On the other hand, the serum creatinine levels significantly decreased in Subgroup A (p = 0.033) and fewer antihypertensive drugs were used after endovascular revascularization (p = 0.041). The preoperative and postoperative creatinine levels and number of antihypertensive drugs were similar in Subgroup B. During the perioperative period, RAS patients with relatively low preoperative renal perfusion levels had greater improvement in renal perfusion, renal function, and blood pressure control after endovascular treatment. The improvement of renal function needs to be confirmed by long-term follow-up.

Influence of Fe–N–C morphologies on the oxygen reduction reaction in acidic and alkaline media

AbstractThe development of nonnoble metal oxygen reduction reaction (ORR) catalysts for fuel cells has been motivated by the high cost and limited supply of noble metals, as well as the desire to improve the performance and durability of this type of energy conversion device. In this study, nonnoble Fe–N–C catalyst was synthesized using a zeolitic imidazole framework (ZIF‐8), poly (aniline), and 10,10′‐dibromo‐9,9′‐bianthry as precursors to produce Fe–N–C with hollow sphere (HS), amorphous bulky structure (B), and sheet‐like thin sheet (N) structure. The Fe–N–C catalyst was analysed in terms of their shape, crystal structure, pore characteristics, and elemental composition. Among all the Fe–N–C catalysts, Fe–N–C_HS had the highest total surface area, followed by Fe–N–C_B and Fe–N–C_N. To evaluate their ORR catalytic activity, a half‐cell electrochemical experiment with .1 M KOH and .1 M HClO4 as the alkaline and acidic electrolytes was conducted. This study revealed that Fe–N–C_HS exhibited the highest onset potential but the Fe–N–C_B has the highest limiting current density in alkaline medium; meanwhile, in acidic media, Fe–N–C_HS shows the best ORR performance with the highest onset potential and limiting current. This highly porous Fe–N–C_HS catalyst also demonstrated active site activation and excellent stability compared with the other samples as well as commercial Pt/C in acidic electrolyte, which suggests its potential for application in proton exchange membrane fuel cells (PEMFCs).

Dark Matter in Fractional Gravity II: Tests in Galaxy Clusters

Recently, in Benetti et al. (Astrophys. J. 2023, 949, 65), we suggested that the dark matter (DM) component in galaxies may originate fractional gravity. In such a framework, the DM component exists, but the gravitational potential associated to its density distribution is determined by a modified Poisson equation including fractional derivatives (i.e., derivatives of noninteger type), which are meant to describe nonlocal effects; as such, this scenario is different from theories where baryonic matter emulates DM-like effects via modifications of gravity (e.g., MONDian frameworks). In Benetti et al., we showed that fractional gravity worked very well for reproducing the kinematics of disk-dominated galaxies, especially dwarfs; there is also preliminary evidence that the strength of fractional effects tends to weaken toward more massive systems. Here, we aim to test fractional gravity in galaxy clusters, with a twofold aim: (i) perform an independent sanity check that it can accurately describe such large and massive structures; (ii) derive a clear-cut trend for its strength in systems with different DM masses. To this purpose, we forward model the density and pressure distributions of the intracluster medium (ICM), working out the hydrostatic equilibrium equation in fractional gravity. Then, we perform a Bayesian analysis of the X-COP galaxy cluster sample and infer constraints on the fractional gravity parameters, for individual clusters as well as stacked clusters. We find that fractional gravity performs remarkably well in modeling the ICM profiles for the X-COP sample. We also check that the DM concentration vs. mass relation is still consistent with the expectations of N-body simulations in the standard cosmological scenario. Finally, we confirm the weakening of the fractional gravity effects toward more massive systems and derive the overall scaling of the fractional gravity parameters from dwarf galaxies to massive clusters, spanning six orders of magnitude in DM mass. Such an overall trend implies that fractional gravity can substantially alleviate the small-scale issues of the standard DM paradigm, while remaining successful on large cosmological scales.

Features of compaction of iron-cast-iron charge at different stages of pressing

The article presents the packing parameters of spherical particles and the characteristics of the granular medium of the iron-cast iron powder mixture. A mathematical analysis is carried out, giving preference to inertial methods of molding products from iron-iron charge. The complexity of obtaining a uniform dependence of the density of an elasticplastic medium on the pressing pressure is shown, taking into account the difference in the mechanisms of compaction of powders at different stages of pressing. Keywords: pressing, powder, particle, coordination number, deformation, packing, granular medium, differential equations. afetceferova8@gmail.com