Degree Of Fragmentation Research Articles

Novel typing scheme reveals emergence and genetic diversity of Chlamydia pecorum at the local management scale across two koala populations

To overcome shortcomings in discriminating Chlamydia pecorum strains infecting the koala (Phascolarctos cinereus) at the local level, we developed a novel genotyping scheme for this pathogen to inform koala management at a fine-scale subpopulation level. We applied this scheme to two geographically distinct koala populations in New South Wales, Australia: the Liverpool Plains and the Southern Highlands to South-west Sydney (SHSWS). Our method provides greater resolution than traditional multi-locus sequence typing, and can be used to monitor strain emergence, movement, and divergence across a range of fragmented habitats. Within the Liverpool Plains population, suspected recent introduction of a novel strain was confirmed by an absence of genetic diversity at the earliest sampling events and limited diversity at recent sampling events. Across the partially fragmented agricultural landscape of the Liverpool Plains, diversity within a widespread sequence type suggests that this degree of fragmentation may hinder but not prevent spread. In the SHSWS population, our results suggest movement of a strain from the south, where diverse strains exist, into a previously Chlamydia-free area in the north, indicating the risk of expansion towards an adjacent Chlamydia-negative koala population in South-west Sydney. In the south of the SHSWS where koala subpopulations appear segregated, we found evidence of divergent strain evolution. Our tool can be used to infer the risks of strain introduction across fragmented habitats in population management, particularly through practices such as wildlife corridor constructions and translocations.

Influence of plasma breakdown on pores and fractures in bituminous coal: A new characterization method of breakdown energy

Plasma technology has a potential application prospect in the field of coal seam permeability enhancement. However, the relationship between plasma breakdown energy and the improvement effect of coal pores and fractures is lack of in-depth research. This study proposed a novel method for characterizing the plasma breakdown energy, and three testing techniques, namely, particle size distribution, mercury intrusion porosimetry (MIP) and low-field nuclear magnetic resonance (NMR), were utilized to examine the pore and fracture distribution of coal samples obtained from Jiulong Mine under varying breakdown energy conditions. The influence between breakdown energy and pores and fractures development is revealed. The results show that: (1) The degree of coal sample fragmentation increases with the increase of plasma breakdown energy. (2) Different breakdown energy induced the development of different pore distribution patterns. At lower breakdown energy, an increase in the volume of macropores dominates. As the breakdown energy increases, there is a rapid increase in the volume of mesopores, a slight increase in minipores, and the least increase in micropores, indicating that plasma treatment primarily improves pores with diameters greater than 100 nm. The test results of the three techniques were mutually verified. (3) Compared with capacitance energy and voltage, the effective breakdown energy obtained by the integral method has a more significant linear relationship with the particle size distribution, total pore volume, and average pore diameter, indicating that the effective breakdown energy is more suitable for characterizing the crushing effect of plasma. During the plasma breakdown process, the expansion stress and thermal stress formed by the effective breakdown energy exceeded the local tensile strength of coal, leading to the generation and development of pores and fractures, which in turn led to the rupture of the coal body. The larger the breakdown energy, the larger the crushing circle formed around the ion channel, the finer the coal is crushed, and the more pore fractures are developed. These nascent pores and fractures provide channels for gas transport, which is extremely favorable for coal mine gas extraction. The research conclusions provide theoretical support for the application of plasma in fracturing and permeability enhancement in coal seams.

β-Glucan fragmentation by microfluidization and TNF-α-immunostimulating activity of fragmented β-glucans

Fragmentation of β-glucans secreted by the fungus Ophiocordyceps dipterigena BCC 2073 achieved by microfluidization was investigated. The degree of β-glucan fragmentation was evaluated based on the average number of chain scissions (α). The effects on the α value of experimental variables like solid concentration of the β-glucan suspension, interaction chamber pressure, and number of passes through the microfluidizer were examined. Kinetic studies were conducted using the relationships of the α and suspension viscosity values with the number of passes. Evidence indicated that α increases with the interaction chamber pressure and the number of passes, whereas the solid concentration shows the inverted effect. Kinetic data indicated that the fragmentation rate increases with β-glucan solid concentration and interaction chamber pressure. Furthermore, since β-glucan molecular weight is a key factor determining its biological activity, the effect of β-glucans of different molecular weights produced by fragmentation on tumor necrosis factor (TNF)-α-stimulating activity in THP-1 human macrophage cells was investigated. Evidence suggested that β-glucans have an immunostimulating effect on macrophage function, in the absence of cytotoxic effects. Indeed, β-glucans characterized by a range of molecular weights produced via microfluidization exhibited promise as immunostimulatory agents.

Characteristics of Local Endograms at the Site of Successful Arrhythmia Suppression During Activation Mapping of Idiopathic Ventricular Arrhythmias Using 3D Navigation

A topical issue is the determination of the optimal values of activation time of local endograms (LE) and bipolar signal morphology during ablation in patients with idiopathic ventricular arrhythmias (VA) at the site of successful suppression, and the influence of 3D navigation on these values.
 The aim. To study earliest activation time (EAT) and LE morphology in the area of successful suppression during ablation of idiopathic VA using 3D navigation.
 Materials and methods. Analysis of the results of ablation in 57 patients with idiopathic VA was made. The patients were divided into two groups. Group I included 30 (52.6%) patients in whom mapping was performed using 3D navigation (EnSite Velocity Cardiac Mapping System). Group II included 27 (47.4%) patients who were mapped using conventional methods.
 In group I, extrasystole was found in 20 (66.7%) patients, while ventricular tachycardia was observed in 10 (33.3%) patients. In group II, extrasystole was revealed in 16 (59.3%) patients, and ventricular tachycardia in 11 (40.7%) patients.
 Group I included 21 (70%) patients with right ventricular localization of arrhythmia and 9 (30%) patients with left ventricular localization. Meanwhile, group II included 17 (63%) patients with a focus in the right ventricle and 10 (33%) patients with that in the left ventricle.
 The morphology of the LE was evaluated according to criteria such as polarity (positive or negative) and degree of signal fragmentation (monomorphic or fragmented). Polarity was determined by the initial direction of the signal during the first 10 ms, regardless of further changes in the endogram. The signal was considered fragmented if there were three or more polarity changes.
 Results. In group I, EAT of LE was -38.0±7.0 ms, while in group II it was -38.0±8.5 ms. No difference was found between the studied groups (p=0.834).
 Among all patients in both groups, the average value of EAT of LE at the site of successful arrhythmia elimination was -37.0±8.5 ms. In 92.9% cases EAT of LE was -30 ms or earlier. Only in four (7.1%) patients it was possible to achieve suppression of the arrhythmia with EAT of LE not earlier than -30 ms, while in all these cases the focus was always localized in the right ventricle. The minimum value of EAT of LE at the site of successful suppression of arrhythmia was -27 ms.
 The dominant morphology at the site of successful suppression among the patients in both groups, regardless of the type of mapping, was positive polarity of endogram.
 Conclusions. Regardless of the mapping method, in the site of successful idiopathic VA suppression LE must precede QRS by at least 27 ms.

A critical role of the capital green belt in constraining urban sprawl and its fragmentation measurement

Urban green belts (UGBs), an important green infrastructure of cities, have the functions of constraining urban sprawl, which are of great significance to urban green, resilient and sustainable development. However, it remains unclear how to quantify the constraining effect of UGBs on urban sprawl and the degree of fragmentation after UGBs constrain urban sprawl. Here, we proposed a UGBs extraction method to explore the spatial evolution of UGBs in the rapidly expanding megacity Beijing from 2000 to 2020. We also quantitatively investigated the role of UGBs in constraining urban sprawl and measured the degree of fragmentation of the UGBs after constraining urban sprawl with the help of the constraint assessment index, the Urban Annual Ring model, and the landscape pattern index. Results showed that: (1) Beijing’s UGBs area showed a “V”-shaped trend of first decreasing and then increasing from 2000 to 2020, decreasing from 332.61 km2 in 2000 to 303.41 km2 in 2015, and then increasing to 369.42 km2 in 2020, which is equivalent to about 54 Beijing Olympic Forest Parks. (2) The UGBs’ role in constraining urban sprawl was characterized by gradual enhancement in three periods from 2005 to 2020. The boundary containment rate (BCR) of urban sprawl was 0.48, 0.22, and 0.14 respectively. After the construction of the newly planned UGBs in 2005, the speed of urban sprawl from 2010 to 2015 decreased by 10.90%. (3) The fragmentation of UGBs showed an upward trend and connectivity showed a downward trend. The patch density (PD) characterizing fragmentation increased from 17.22 in 2000 to 31.60 in 2020, and the patch aggregation index (AI) characterizing connectivity decreased from 86.92 to 79.73. The research can provide a reference for other similar sized cities in UGB planning and government decision-making.

A novel ultrasonic-assisted technique for eco-friendly extraction of oligostilbenes from the Paeonia delavayi seed coat and the inhibition on 3 C-like protease

The main purpose of this study is to establish an efficient method for extracting oligostilbenes from the Paeonia delavayi Franch seeds coat (PDSC), and explore their inhibition on 3 C-like protease (3CLpro). Ultrasonic-assisted natural deep eutectic solvent (UAE-NADES) method was used to extract oligostilbenes from PDSC, and the extraction process conditions were optimized using response surface methodology (RSM). The inhibition of oligostilbenes on 3CLpro, an enzyme necessary for replication of 2019-nCoV, was tested by fluorescence intensity (FI) method. The optimistic extraction conditions were determined as follows: ultrasonic time 18 min, ultrasonic temperature 35°C, Choline chloride/Sorbitol/Ethylene glycol (CSEG) molar ratio 2:1:4, ultrasonic power 300 W. Under these extraction conditions, the extraction rates of suffruticol A (SA), suffruticol B (SB), suffruticol C (SC), trans-ε-viniferin (TV), trans-gnetin H (TG), and total oligostilbenes compounds (TOC) were 73.66 ± 4.32%, 78.74 ±5.28%, 88.12 ± 5.16%, 91.82 ± 6.62%, 89.12 ± 6.37% and 88.27 ± 5.38%, respectively. The UAE-NADES method had lower extraction temperature and better extraction efficiency for oligostilbenes than those of reflux extraction (RE) and ultrasonic-assisted solvent extraction (UASE). SEM analysis found that PDSC powder extracted by UAE-NADES had the most pores and the highest degree of fragmentation, which could fully promote the dissolution of oligostilbenes. Bioactivity evaluation revealed that compounds suffruticol A (SA), suffruticol B (SB), suffruticol C (SC) inhibited 3 CLpro in a dose-dependent manner, and the inhibitory effect of SB and SC could reach up to 70.89% and 77.43%, respectively, indicating that oligostilbenes had a potential inhibitory effect on 3CLpro. This study laid a foundation for the efficient extraction of oligostilbenes which has the potential application as a potential therapeutic drug for COVID-19 by UAE-NADES.

Characteristics Analysis and Prediction of Land Use Evolution in the Source Region of the Yangtze River and Yellow River Based on Improved FLUS Model

Climate change profoundly alters land use in alpine regions, and delving into the evolutionary characteristics of these changes is crucial for the sustainable development of regional land resources and the gradual enhancement of the ecological environment. Taking the source region of the Yangtze and Yellow River (SRYAYE) as a case study, we integrate permafrost and snowfall data into the Future Land Use Simulation model (FLUS). Analyzing historical land use, we predict and simulate the land use scenarios for 2030, 2035, and 2060 under SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5 climates, and conduct a detailed analysis of the scale, composition, and pattern of land use in this area. Scale. The results showed that ① the Kappa coefficient of the improved FLUS model was higher than 0.927, and that the overall accuracy of the simulation was increased by 2.64%; ② the area of forest land and the high-coverage grassland will increase in the future and the center of gravity will migrate to the west, and that the area of moderate and low-coverage grassland will slightly decrease but tend to become green to the west; and ③ the fragmentation degree of the SRYAYE is decreasing, and the influence of human activities on the landscape pattern is weaker than in the past.

Analysis of Pore Characterization and Energy Evolution of Granite by Microwave Radiation

To study the dynamic response of granite to different levels of microwave power, an intelligent microwave rock-breaking instrument is used to irradiate different power from three directions. The servo universal testing machine is used to carry out a uniaxial compression test on the granite after microwave damage to analyze the strength damage characteristics and the degree of pore damage. Pore fractal characteristics are analyzed based on nuclear magnetic resonance to establish the microwave damage degradation model. In parallel, the energy evolution process of granite under the influence of various power levels is analyzed using the theory of energy dissipation. Simultaneously, based on the energy dissipation theory, we analyze the energy evolution process of granite under the action of different powers. The results show that with higher microwave power, the peak strength and modulus of elasticity show a linear decreasing law. The degree of fragmentation is more obvious, showing the damage characteristics with two big ends and little in the middle. The higher the power, the greater the porosity and the more sensitive the micropore becomes to microwaves. Additionally, the damage degradation model established to evaluate the microwave damage of the rock showed that it was feasible. The higher the power, the lower the total energy, elastic energy, and dissipation energy, and the granite is gradually transformed from elastic deformation to plastic deformation. The elastic energy ratio decreases, the dissipation energy ratio increases, and the degree of damage becomes more and more serious. This study provides theoretical support for exploring the mechanical behavior and mechanism of microwave-assisted rock breaking and is of great practical significance.

Taphonomy of the fauna and chert assemblages from the Middle Palaeolithic site of Vajo Salsone, Eastern Italian Alps

The Vajo Salsone site is located at an altitude of 376m a.s.l. on the right slope of the Valpantena valley, in the Veneto Pre-Alps, north of the town of Verona. The site was discovered in 2017 during the construction of a truckable road. It is a small and narrow karst cavity filled with Pleistocene sediments that yield abundant Middle Palaeolithic artefacts and faunal remains, often coated by carbonate encrustations. The lithic assemblage shows the predominance of the Levallois method and is characterised by a large number of retouched elements, including foliated points. These artefacts, typical of the Late Middle Palaeolithic period in central and south-eastern Europe, make Vajo Salsone an exceptional case, as their recovery is rather sporadic west of the Balkan Peninsula and south of the Alps. The fauna is dominated by ungulates, the most abundant being the red deer followed by roe deer, chamois and elk. Among the carnivores, wolf is common, while fox and bear are rare. This fauna suggests an environment characterised by open glades and closed forests, with a discontinuous presence of alpine grasslands and wetlands. Taphonomic analysis of the bone surfaces is complicated by the presence of concretions on most of the remains, which also show a high degree of fragmentation. Post-depositional fractures are common, and weathering is light. Only cervid bones show anthropogenic modifications related to hunting and hominin exploitation such as cut marks, scraping, impacts and burnt modifications. Some long bone diaphysis bear marks testifying to the use of these fragments as retouchers for flint artefacts. Such use has been evidenced at other Middle Palaeolithic sites in the area. Furthermore, the good state of preservation of the occlusal surface enamel of the cervid teeth allowed us to carry out meso and microwear analyses which provided data on seasonality and site occupation. With regard to dental wear analysis, the red deer from Vajo Salsone had mesowear suggesting a mixed feeding and grazing diets, whereas microwear analysis showed that the individuals had a diet between mixed feeding and browsing. The taphonomic study of the site has been integrated by X–RFS analysis of the alterations occurred to the lithic artefacts, which include deep patination and the formation of calcareous crusts. All the data presented here are consistent with the hypothesis of a short-distance displacement of the material from a single archaeological deposit possibly related to human occupation during the warm season.

Analysis of Dynamic Mechanical Properties and Energy Consumption of Fractured Sandstone under Dynamic–Static Combination Conditions

Under dynamic loads, such as blasting, excavation, or quarrying, rocks with fissures are the first to sustain damage, leading to instability in the engineering rock mass. To investigate the kinetic properties of fractured rocks, fractured coal mine sandstone specimens underwent impact compression tests using a dynamic–static combination SHPB (split Hopkinson pressure bar) test device at different loading rates under combined dynamic and static conditions. The damage characteristics of the specimens were analyzed from an energy point of view. The results show that under the dynamic and static combined condition, when five impact loading air pressures are used for loading at different impact rates, the trends of the dynamic stress–strain curves of prefabricated fissured rock samples under various impact pressures were discovered to be similar and were mainly categorized into three main stages of elasticity, yield, and destruction; the specimen’s dynamic compressive strength increases according to a power function relationship; as the average strain rate increases, the dynamic strain increases linearly and the dynamic modulus of elasticity increases in a quadratic relationship, all of which show a significant strain rate effect. The incident energy is a power function of the loading rate. The reflected, transmitted, and absorbed energies by the sample increase with the incident energy. The degree of the sandstone specimen fragmentation gradually grows with increasing impact loading rate and incident energy, as evidenced by a decrease in the scale of the fragments. The absorbed energy in the sample is mainly used for the deformation damage of the rock, and the more intense the fragmentation of the specimen, the more absorbed energy is required.

Impacts of Climate Change on the Biogeography and Ecological Structure of Zelkova schneideriana Hand.-Mazz. in China.

This study utilized the platform for ensemble forecasting of species distributions, biomod2, to predict and quantitatively analyze the distribution changes of Zelkova schneideriana Hand.-Mazz. under different climate scenarios (SSP1-2.6 and SSP5-8.5) based on climate and land-use data. This study evaluated the geographic range changes in future distribution areas and the results indicated that, under both SSP1-2.6 and SSP5-8.5 scenarios, the distribution area of Zelkova schneideriana would be reduced, showing a trend towards migration to higher latitudes and elevations. Particularly, in the more extreme SSP5-8.5 scenario, the contraction of the distribution area was more pronounced, accompanied by more significant migration characteristics. Furthermore, the ecological structure within the distribution area of Zelkova schneideriana also experienced significant changes, with an increasing degree of fragmentation. The variables of Bio6 (minimum temperature of the coldest month), Bio2 (mean diurnal temperature range), Bio15 (precipitation seasonality), and elevation exhibited important influences on the distribution of Zelkova schneideriana, with temperature being particularly significant. Changes in land use, especially the conversion of cropland, had a significant impact on the species' habitat. These research findings highlight the distributional pressures faced by Zelkova schneideriana in the future, emphasizing the crucial need for targeted conservation measures to protect this species and similar organisms.

(203) Impact of Smoking on Sperm Chromatin Integrity

Abstract Introduction Semen analysis is an essential component of infertility evaluation, but it may still fail to detect subtle sperm defects present in patients with male factor infertility. Although estimates vary, approximately 15% of patients with male factor infertility have normal spermiograms It is necessary to identify diagnostic measures for male infertility that are easy to perform, inexpensive, and provide an accurate diagnosis. Tests that assess sperm quality should not only identify the ability of spermatozoa to reach the oocyte but also their ability to fertilize the oocyte and activate embryo growth. The estimation of sperm DNA damage fills the above need in the diagnosis of male infertility Abnormalities in the male genome characterized by damaged sperm DNA may be indicative for male subfertility regardless of routine semen parameters, and these parameters do not reveal sperm DNA defects Men with normal semen analysis may also have a high degree of DNA fragmentation, which can be a major cause of undiagnosed/unexplained infertility. Sperm DNA fragmentation may result from aberrant chromatin packaging during spermatogenesis, defective apoptosis before ejaculation or excessive production of reactive oxygen species (ROS) in the ejaculate. Objective To study the impact of cigarette smoking on sperm chromatin integrity in infertile patients. Methods The present study included eighty infertile male patients recruited from the Andrology Outpatient Clinic at Al-Azhar University Hospitals The patients were divided into two groups: - Group I: forty nonsmoker infertile males. (Control Group). Group II: forty cigarette smoker infertile males. (Study Group) Results The current study revealed that smoking increases the abnormality of sperm chromatin integrity in sperms of smokers. This is evident by the positive correlation of increased head stainability of sperms in smokers compared to nonsmokers. The value of partially stained sperm heads using aniline blue is calculated from the total staining score formula, this score was found to increase significantly among smokers in comparison to nonsmokers. In the present study, the increased severity of smoking (smoking index), was not correlated with the degree of sperm head stainability. This mean that, smoking insult on sperm chromatin integrity is crucial regardless the duration or the amount of the consumed cigarettes Conclusions There is a significant increase of sperm chromatin damage in smoker infertile patients than nonsmoker infertile patients and these damages may affect the quality of the ejaculated spermatozoa and decrease their fertility potential. Not only semen parameters but also sperm chromatin condensation is affected significantly by smoking. Aniline blue staining is an effective and inexpensive tool for assessment of the fertilization potentiality of infertile patients. A significant correlation was found between the percentage of spermatozoa with normal sperm chromatin condensation and normal morphology. Cigarette smoking may have a negative impact on sperm quality and DNA integrity. Therefore, it would be advisable for men to abstain from smoking to avoid decreased fertility. Disclosure No.

Experimental study on the quasi-static and dynamic tensile behaviour of thermally treated Barakar sandstone in Jharia coal mine fire region, India

In the present study, the effect of mild to high-temperature regimes on the quasi-static and dynamic tensile behaviours of Barakar sandstone from the Jharia coal mine fire region has been experimentally investigated. The experimental work has been performed on Brazilian disk specimens of Barakar sandstone, which are thermally treated up to 800 °C. The quasi-static and dynamic split tensile strength tests were carried out on a servo-controlled universal testing machine and Split Hopkinson Pressure Bar (SHPB), respectively. Microscopic and mineralogical changes were studied through a petrographic investigation. The experimental results suggest the prevalence of both, static and dynamic loading scenarios after 400 °C. Up to 400 °C, the quasi-static and dynamic tensile strengths increased due to the evaporation of water, which suggests a strengthening effect. However, beyond 400 °C, both strengths decreased significantly as newly formed thermal microcracks became prevalent. The dynamic tensile strength exhibits strain rate sensitivity up to 400 °C, although it shows a marginal decline in this sensitivity beyond this temperature threshold. The Dynamic Increase Factor (DIF) remained constant up to 400 °C and slightly increased after 400 °C. Furthermore, the characteristic strain rate at which the dynamic strength becomes twice the quasi-static strength remains consistent until reaching 400 °C but steadily decreases beyond this temperature. This experimental study represents the first attempt to validate the Kimberley model specifically for thermally treated rocks. Interestingly, the presence of water did not have a significant impact on the failure modes up to 400 °C, as the samples exhibited a dominant tensile failure mode, breaking into two halves with fewer fragments. However, as temperature increased, the failure behaviours became more complex due to the combined influence of thermally induced microcracks and the applied impact load. Cracks initially formed at the centre and subsequently, multiple shear cracks emerged and propagated in the loading direction, resulting in a high degree of fragmentation. This study also demonstrates that shear failure is not solely dependent on the loading rate but can also be influenced by temperature, further affecting the failure mode of the sandstone.

Design and Experiment of Profiling Furrow-Ridge Terrain by Cane Leaf-Chopping and Returning Machine

Design and Experiment of Profiling Furrow-Ridge Terrain by Cane Leaf-Chopping and Returning Machine

A fragmentation-aware redundancy elimination scheme for inline backup systems

Data deduplication is a widely employed technique in backup systems to enhance storage efficiency by eliminating duplicate chunks. Delta compression is a technique that complements deduplication by removing redundant data between similar chunks. However, when integrated into deduplication-based backup systems, delta compression can considerably decrease backup throughput due to the additional I/Os for fetching base chunks. Moreover, data deduplication can lead to chunk fragmentation, causing continuous chunks in a backup to become fragmented. We observe that the number of additional I/Os for fetching base chunks when delta compression is applied depends on the degree of chunk fragmentation. When chunk fragmentation is not significant, delta compression can improve storage efficiency without significantly impacting backup throughput. Based on this observation, we propose a redundancy elimination approach called Fragmentation-aware Redundancy Elimination (FaRE) for in-line backup systems.The main idea behind FaRE is the combined use of three techniques: fragmentation estimation for assessing the degree of chunk fragmentation, sequential deduplication to significantly reduce chunk fragmentation by only deduplicating against chunks with sequential layout when fragmentation is severe, and local redundancy elimination to greatly enhance storage efficiency by performing both deduplication and delta compression when chunk fragmentation is not significant. Our evaluation results demonstrate that FaRE achieves higher storage efficiency and restoration performance compared to traditional approaches that only adopt deduplication for redundancy elimination, while achieving comparable backup throughput due to the limited number of additional I/Os required.

DESTRUCTION OF ROCKS BY EXPLOSION DURING OIL TRANSPORTATION

When oil and gas wells are ready for operation, when drilling is carried out at the bottom of the well to establish contact with the formation, it is considered that the degree of crushing of the rocks is proportional to the speed of application of the load. As a result of the stresses created by them, the degree of fragmentation is higher. In the article, it is proposed to take into account the quality of crushing of the necessary rock by using some empirical coefficients in the calculation formulas. The dynamics of the rock dispersion process is studied on the basis of the hydrodynamic hypothesis. Here, the solution of the system of differential equations is given based on the fundamental laws of conservation of mass, energy and momentum. Based on the strength properties of mountain rocks, broken lines are found in the continuum of the whole environment, which determines the final effect of rock crushing. However, the accepted assumptions about the incompressibility of the rock and the transfer of the explosive impulse to the immediate environment significantly reduce the practical value of the results. It should be noted that in the immediate area directly adjacent to the load, the mountain rock is under uneven volume compression. In this case, the largest tangential stresses occur mainly in planes oriented at an angle of 450 to the radial direction. Thanks to this, a system of spiral sliding lines breaks the rock into small blocks. Outside this zone, a system of radial cracks is formed as a result of the expansion of the massif. When the pressure in the gas cavity decreases and the mass moves back in the direction of the load, tangential cracks appear. The combination of the volume compression zone and the reach zone constitutes the controlled crushing area. When the compression wave reaches the bare surface, it becomes a stress wave. As this wave travels from the surface to the load, it forms a system of jump cracks. The high explosive effect of explosive gases with sufficient explosion energy causes the release of such shattered rock. Obviously, this concept is very important for the development of the theory of explosive disintegration of mountain rocks. Because there is no unequivocal relationship between the nature of the dissolution of the rock and the acoustic hardness. One of the first to clearly describe the mechanism of shock wave formation and its transformation into a more explosive and seismic wave when detonation reaches the boundary of the charge cavity. In rocks, shock waves are formed during the entire time of expansion of the gas cavity. It explains in detail the mechanism of cracking phenomena by considering the cracks as a source of multiple reflections of the stress wave. Keywords: rock strength, constant material, scale effect, rocks, destruction probability, fractured, robustness theory, microcrack, mineral, experience constant, density of defects, displacement, compression.

BlastAssist: a deep learning pipeline to measure interpretable features of human embryos.

BlastAssist: a deep learning pipeline to measure interpretable features of human embryos.

Distinctive shear zones demonstrate pervasive laminar cataclastic flow throughout the gigantic Iymek rock avalanche

Intensive fragmentation is a pervasive process during rock avalanche propagation, with a series of typical shearing characteristics being generated, indicating the occurrence of differential shear-induced comminution of clasts. However, much less is known about how shearing evolves within a rock avalanche over long runout. In the Iymek rock avalanche (IRA), pervasive shear zones characterized by multistoried, multiscale, and multistyle shear structures are well developed along the travel path of the IRA, providing an invaluable opportunity to decipher the evolution of shear-induced fragmentation occurred in rock avalanches. In these shear zones, a series of indicative structures, including preserved stratigraphic sequences, jigsaw structures, Riedel shear arrays, sigmoidal shear planes, asymmetrical folds, bookshelf and boudin-like structures, and anastomosing shear networks, are identified. These structures indicate that a laminar-like flow regime characterized by low disturbance but intensive shearing should dominate the emplacement of the IRA, contributing to the formation of these pervasive shear structures and material facies. As indicated by the progressive evolution of these pervasive shear structures, three facies are determined from the transition zone to the accumulation zone, i.e., low-fragmented facies, ductile-dominated facies and brittle-dominated facies. The low-fragmented facies is mainly distributed in the transition zone, similar to a semisolid phase rather than the solid phase of the bedrock in the source area. Conversely, the brittle-dominated facies features a high fragmentation degree and is predominant in the accumulation zone, which mainly consists of a semifluid to fluid phase. This indicates that the rock avalanche mass should evolve from a solid phase to a fully fluid phase during propagation, which involves clast fracturing and comminuting, frictional sliding and rotation. Therefore, we propose that the rock avalanche is a classical cataclastic flow driven by progressive and differential shearing comminution during its laminar-like propagation instead of a granular flow. These results provide a significant basis for interpreting similar structures in other rock avalanche deposits and yield new insights for understanding the emplacement mechanisms of rock avalanches.

Hungry or Not: How Stellar-Mass Black Holes Grow (or Don’t) in Dark Matter Mini-Haloes at High-Resolution

Abstract We compare the performance of the popular Bondi-Hoyle-Lyttleton (BHL) accretion scheme with a simple mass-flux scheme applied to stellar-mass black holes (BHs) across six levels of increasing spatial resolution. Simulating the formation of black holes within cosmological mini-haloes at z ∼ 20, we investigate scenarios both with and without supernova events, which result in BHs of initial mass 10.8 M⊙ and 270 M⊙ respectively. Our explicit focus on the stellar-mass range pushes the maximum resolution down to sub-10−3 pc regimes, where more complicated gas dynamics are resolved. We observe efficient growth and rotationally supported, ∼10−1 pc-scale discs around all 270 M⊙ BHs independent of resolution and accretion scheme, though clumps, bars, and spiral arm structures impact stability at high resolution. We analyse the effect of these instabilities on the accretion cycle. In contrast, all bar one of the 10.8 M⊙ BHs fail to attract a disc and experience modest growth, even when characteristic scales of accretion and dynamical friction are reasonably resolved. While the two accretion schemes somewhat converge in mass growth for the 270 M⊙ case over 1 Myr, the greater degree of gas fragmentation induces more randomness in the evolution of the 10.8 M⊙ BHs. We conclude that early universe black holes of MBH ∼ 101 M⊙ struggle to grow even in gas-rich environments without feedback in comparison to seeds of MBH ∼ 102 M⊙, and the latter exhibit convergent growth histories across accretion schemes below a resolution of dx = 1 × 10−3pc.

Exposition and Slope Relief Indicators of the Tovuzchay-Esrikchay Rivers Basin

The Tovuzchay basin, located on the northeastern slope of the Lesser Caucasus, is surrounded by the Kura River from the north, the Agstafachay basin from the west and the Zayamchay basin from the east. The relief of the basin has an ancient history of development and was formed under the influence of endodynamic processes together with the geological structure. The relief, geological and geomorphological structure of the area were studied in detail by V. Khain, Sh. Azizbekov, L. Leontiev, M. Kashgai and other researchers. Relief plays an important role in determining the direction of land use as the main component of ecosystems and geosystems, and also has a significant impact on human economic activity. The study of relief slope, degree of fragmentation, slope direction, slope and other factors is a morphometric analysis of the terrain, and plasticity maps based on them serve as the basis for agroecological assessment of lands.