Relative Distribution Research Articles

Molecular Dynamics Simulation of CH4 Displacement through Different Sequential Injections of CO2/N2

As a clean energy source, coalbed methane (CBM) produces almost no exhaust gas after combustion, and its extraction and efficient utilization play a key role in supporting sustainable development. Therefore, molecular dynamics simulations were used to research the diffusion of CH4 in coal after injecting CO2/N2 in different sequences and to clarify the efficiency of CBM extraction under different injection sequences, so as to contribute to sustainable development. The results show that the adsorption amounts of CO2 and N2 in different injection sequences are obviously different. To narrow the gap between the two injection amounts, the injection pressure of N2 can be appropriately increased and that of CO2 can be reduced, or N2 can be injected preferentially instead of CO2. When CO2 is injected first, the interaction energy between CH4 and coal is stronger and increases slightly with displacement time as a whole. The interaction energy curve of the N2 injection decreases, and the displacement effect becomes worse and worse. From the diffusion and relative concentration distribution of CH4, it can be seen that the diffusion of CH4 molecules outside the grain cell is more obvious when N2 is injected first. In terms of the number of CH4 molecules diffusing outside the crystal cell, it is less when CO2 is injected first than when N2 is injected first. The average value of the velocity distribution of CH4 increases slightly when CO2 is injected first and decreases significantly when N2 is injected first, but the average value is overall higher for N2 injection first. From the difference in diffusion coefficients before and after the gas injection, it can be seen that the decrease in permeability due to the expansion of the coal matrix by CO2 is more obvious than the increase in permeability due to the contraction of the coal matrix by N2.

Measurement and modelling of the moisture distribution in early-age concrete in the joint of composite beam and hollow core slab

The building moisture in concrete can damage the surface material if applied too early before the excess moisture has dried out. The composite beam forms an abnormal structure at the joint of the hollow-core slab, in which the thickness of the structural concrete is almost the thickness of the entire slab. For this reason, the joint of the beam and hollow core slab must be taken into account when assessing the adequate drying of concrete structures. The considered composite beams are steel casing beams, which are casted full of concrete. To achieve a composite structure, there are holes in the sides of the casing, through which moisture from the concrete transfers to the surrounding structure. However, the drying of the concrete inside the beam is significantly limited. The level of relative humidity of the concrete inside the beam remains moderately high for a long time, depending on the quality of the concrete and, consequently, the self-desiccation of the concrete. When using concrete with a low water binder ratio, drying occurs at a level of about 85%RH as a result of self-desiccation. In the study, relative humidity in the joint was measured continuously and with instantaneous measurements. The relative humidity in the joint concrete was also monitored after the surface structure layers were installed. In addition, humidity was measured from below the surface material and continued until equilibrium was reached. The structure was simulated as a 3D model and studied using a concrete material model which takes into account the self-desiccation and the thermal dependence of the sorption. A good agreement was found to describe the effect of temperature changes on the relative humidity of concrete that can be observed in continuous measurement. In addition, a suitable prediction of relative humidity below the surface material can be achieved based on modelled relative humidity distribution before the installation of the surface structure.

Crystallographic Structure and Quantum-Chemical Analysis of Biologically Active Co(III)-Pyridoxal–Isothiosemicarbazone Complex

Semicarbazones and their transition metal complexes have been investigated as biologically active compounds. This study explores the synthesis, X-ray crystallographic structure, and characterization of a novel Co(III) complex cation with a pyridoxal-isothiosemicarbazone (PLITSC) ligand, [Co(PLITSC-2H)(NH3)3]+. The structure of the complex was further elucidated by the elemental analysis and spectroscopic techniques (IR and UV–VIS). Hirshfeld surface analysis was applied for the investigation of intermolecular interactions governing crystal structure. Optimization was performed at the B3LYP/6-31 + G(d,p)(H,C,N,O,S)/LanL2DZ(Co) level of theory without any geometrical constraints. The selected level of theory’s applicability was proven after comparing experimental and theoretical bond lengths and angles. The antibacterial activity of the complex towards E. coli and B. subtilis was determined and qualified as moderate compared to Streptomycin. The formation of free radical species in the presence of the complex was further verified in the fluorescence microscopy measurements. The molecular docking towards neural nitric-oxide synthase in the brain has shown that the complex structure and relative distribution of ligands were responsible for the binding to amino acids in the active pocket.

Experimental study on the mechanical behavior and energy absorption capacity of coral sand at high strain rates

This study investigated and compared the compression responses and energy absorption capacities of coral sand and silica sand at a strain rate of approximately 1000 s−1. To this end, the effects of the relative density and particle size distribution on the abovementioned properties were analyzed, and the stress–strain curves, yield stresses, compressibilities, energy absorption curves, and energy absorption ratios were obtained. The experimental results showed that coral sand had a significantly higher energy absorption capacity than silica sand owing to its higher compressibility. The energy absorption curve for sand was primarily influenced by the yield stress and energy absorption ratio. The lower relative density of coral sand contributed to its higher compressibility and energy absorption capacity compared to silica sand. For coral and silica sands with different particle sizes, the intersection of the stress–strain and energy absorption curves was observed and analyzed. Formulas for predicting the yield stress, compressibility, and energy absorption curve of coral sand were derived, considering the variations in the relative density and particle size. The study findings reveal that using poorly graded coral sand with large particle sizes can improve the energy absorption capacity of coral sand.

Maternal Vitamin D Deficiency in Mice Sex-Dependently Affects Hepatic Lipid Accumulation in Offspring.

Vitamin D deficiency (VDD) is becoming a global issue and low 25-hydroxyvitamin D (25(OH)D) plasma levels have been linked to hepatic steatosis in adulthood. Nevertheless, the impact of maternal VDD on lipid metabolism and hepatic steatosis remains poorly documented, especially under obesogenic condition. The goal of this study is to assess the effects of maternal VDD on hepatic lipid accumulation in adult offspring fed a normal or obesogenic diet. Several approaches are implemented including histology and lipidomics on the liver in both males and females. No major impact of high-fat (HF) or VDD is observed at histological level in both males and females. Nevertheless, in males born from VDD mice and fed an HF diet, an increase of total lipids and modulation of the relative lipid species distribution characterized by a decrease of triglycerides and increase of phospholipids is observed. In female no major lipid profile is noticed. Maternal VDD combined with a HF diet in male may predispose to hepatic hypertrophia, with a specific lipid profile. Such observations reinforce our knowledge of the impact of maternal VDD on hepatic programming in the offspring.

Molecular dynamics study on the effect of inorganic salts on the wettability of surfactants on bituminous coal: Sodium dodecyl sulfate and sodium chloride as representatives

To further enhance the wetting ability of surfactants to coal, the mechanism of improving the wetting performance of SDS to bituminous coal by the addition of inorganic salt NaCl was studied through a combination of molecular dynamics (MD) simulation with experimental measurements. In the experiment part, the surface tensions of the mixed NaCl-SDS solutions and the contact angles on the bituminous coal surface were measured. Furthermore, MD simulations were conducted to investigate the adsorption characteristics and wetting mechanism of a mixed NaCl-SDS solution on the coal surface at the atomic scale. In this process, the static potentials of the H2O molecule, coal molecule and SDS molecule were calculated, and the number of hydrogen bonds (H-bonds) formed throughout the whole simulation process, the average H-bond length, the relative concentration distribution (RCD) curve and the mean square displacement (MSD) curve were obtained. The experimental results showed that the surface tension and contact angle were both decreased by the addition of sodium chloride in mixed solutions. When 0.6 mol/L NaCl was added, the surface tension and contact angle reached the minima of 30.45 mN/m and 13.01°, respectively. The MD simulation results showed that, after the addition of NaCl, diffusion and migration of H2O molecules were limited, the number of H-bonds increases, the average bond length decreased, the sorption between H2O molecules and coal molecules was enhanced, and the hydrophilicity of coal surface was improved, which meant that the wetting ability of SDS solution to bituminous coal was enhanced by adding NaCl. The effect of the added NaCl in improving the wettability of SDS on coal was explored from two perspectives with macroscopic experiments and microcosmic simulations, and the added NaCl improved the effects of dust suppressants, and played a key role in preventing dust hazards in coal mines.

A preliminary metabarcoding analysis of Portuguese raw honeys.

The microbial diversity in Portuguese raw honeys remains largely uncharacterized, constituting a serious knowledge gap in one of the country's most important resources. This work provides an initial investigation with amplicon metabarcoding analysis of two Lavandula spp. from different geographical regions of Portugal and one Eucalyptus spp. honey. The results obtained allowed to identify that each honey harbors diverse microbiomes with taxa that can potentially affect bee and human health, cause spoilage, and highlight bad bee-hive management practices. We verified that prokaryotes had a tendency towards a more marked core bacterial and a relative homogenous taxa distribution, and that the botanical origin of honey is likely to have a stronger impact on the fungal community. Thus, the results obtained in this work provide important information that can be helpful to improve this critical Portuguese product and industry.

Development of typical meteorological years based on quality control of datasets in Indonesia

This study aims to demonstrate the comprehensive development of typical meteorological years (TMYs) under relatively limited observational data. The distribution of missing hourly observational data of the 2011–2020 period at all sites was examined. This paper proposes a quality control method for filling the gaps in the missing hourly observational data using bias-corrected ERA5 reanalysis data in the process of developing TMYs. Initially, the temperature bias distribution from −4.5 °C to 2.7 °C was reduced to a range of −0.014 °C to 0.005 °C. The relative humidity bias distribution was −6 % to 10 %, and was reduced to −0.32 % to 0.07 %. The bias distribution of wind speeds ranging from −4 m/s to 2 m/s was reduced to −0.02 m/s to 0.35 m/s. The Sandia method with a modified weighting of Finkelstein-Shaffer (FS) statistics was applied to eight climate elements, namely, global horizontal irradiance, direct normal irradiance, diffuse horizontal irradiance, temperature, precipitation, wind speed, relative humidity, and dew point temperature to generate TMYs at 106 sites across eight climate zones in Indonesia. The verification results showed that the average correlation and RMSE between TMYs and their long-term averages were 0.96 and 75 w/m2 for global horizontal radiation, respectively, while those for temperature were 0.86 and 1.3 °C, respectively.

Cisco population characteristics in Wisconsin lakes in relation to lake‐ and landscape‐level factors

AbstractObjectiveDeclines in Cisco Coregonus artedi populations in some inland lakes have prompted assessments of Cisco occurrence and extirpation risk in relation to various stressors to identify refuge lakes and factors that promote Cisco persistence. However, most previous assessments have focused on presence–absence of Cisco rather than examining how population characteristics, such as relative abundance or growth, might change in relation to lake‐ and landscape‐level environmental factors. Consequently, our specific objectives were to identify important environmental factors explaining variation in Cisco relative abundance and growth and to determine whether population metrics describing size and age distributions were related to relative abundance in Wisconsin inland lakes.MethodsCisco were collected from 48 inland Wisconsin lakes during 2011–2015 using vertical monofilament gill nets and population‐specific relative abundance estimates (catch per unit effort [CPUE]) were quantified as the number of individuals per gill‐net night. Sagittal otoliths were removed from a subsample of Cisco for age estimation and growth was indexed as mean total length (TL; mm) at age 2. Length and age data were used to develop a suite of metrics describing size and age distributions of each population. Random forest models were used to evaluate relationships between 10 biologically relevant predictor variables representing variation in physical, climatic, catchment, and limnological characteristics and Cisco CPUE and growth. Pearson correlations were used to determine whether population characteristics were related to CPUE.ResultCisco populations exhibited large variation in relative abundance, growth, and size and age distributions. Best‐fit random forest models explained approximately 25% of the variation in Cisco CPUE and 46% of the variation in growth. Growing degree‐days and variables associated with availability, quality, and quantity of suitable oxythermal conditions were identified as important predictors of both Cisco CPUE and growth; CPUE was also identified as an important predictor of growth. Mean TL and mean TL at age 2 were negatively related to Cisco CPUE, whereas mean age, number of age‐classes present, and maximum observed age were positively related to CPUE.ConclusionOur results suggest that maintenance of suitable oxythermal habitat conditions may be critical to conserving abundant Cisco populations. Our assessment also provides insights on how Cisco populations may respond to environmental and anthropogenic stressors, which could aid ongoing and future conservation and management efforts in Wisconsin and elsewhere.

Comprehensive analysis of structural and thermal performance for the concrete and steel joints used in the assembled building

The structure joints and connection type of buildings play a decisive role in their safety and reliability. Therefore, most studies have focused on the structural performance, ignoring their thermal performance. Three common assembled concrete joints and four steel joints usually used in the assembled building were selected to study their bearing capacity, seismic performance and stiffness degradation. In addition, the temperature and relative humidity distribution of six types of envelopes were evaluated within a year and the effect of different envelope options on the linear thermal transmittance of each joint was investigated. The results show that the best structural performance of concrete joints and steel joints are the grouting sleeve joint and the cantilever section bolt connection respectively. The seismic performance of steel joints is generally stronger. Furthermore, for every 25 mm increase in AAC thickness, the overall linear thermal transmittance of the component increases by 0.02–0.04 W·m−1·K−1. On balance, the grouting sleeve joint is the optimal concrete joint in terms of both structural and thermal performance, but better damp proofing measures are necessary outside of it. Moreover, the cantilever section bolt connection is the optimal steel joint and requires better insulation measures. Interestingly, the building envelope construction of “75 mm autoclaved aerated concrete + 90 mm mineral wool + 75 mm autoclaved aerated concrete” is the best choice for matching joints.

Dual Branding by National Brand Manufacturers: Drivers and Outcomes

This article is the first generalizable empirical analysis of dual branding, that is, the supply of private labels (PLs) by national brand (NB) manufacturers. The authors compile a unique data set combining the identity of PL suppliers in over 260 packaged goods categories with multiple years of scanner data in the Spanish grocery market to offer several contributions. First, they provide new descriptive insights on the prevalence of dual branding in categories where the manufacturer does and does not have NBs, the longevity of PL supply arrangements, and the differences in PL sourcing across retailers. Second, they integrate the literature on motivators and dissuaders of dual branding and test the impact of relevant manufacturer, retailer, and dyad characteristics on PL supply in NB and non-NB categories. The results reveal a more nuanced empirical reality than is evident from prior research regarding the role of multicategory scope, fighter brands, NB differentiation, and size and positioning of the retailer's PL. Third, they examine the outcomes of PL supply for the NBs of dual branders and find that starting (terminating) PL supply to a retailer significantly benefits (hurts) the relative distribution depth but not the relative share of the dual brander's NBs at that retailer.

Hematopoietic loss of Y-chromosome in monocytes from heart failure patients associates with cardiac fibrosis signaling

Abstract Background Hematopoietic mosaic loss of Y chromosome (LOY) increases with age and associates with increased cardiovascular disease incidence. Furthermore, recent murine studies suggest that LOY could potentially promote cardiac fibrosis by stimulating the infiltration and activation of bone marrow-derived macrophages. Yet, specific signatures of hematopoietic LOY cells in patients with heart failure (HF) are missing. Methods and results To decode the genetic signature of circulating hematopoietic cells and assess the effects of LOY in human leukocytes, we performed single-cell RNA-sequencing (scRNA-seq) of immune cells from 10 male patients with chronic HF (mean age 67.3 years, ejection fraction 34.4%). We sorted immune cells by presence or absence of Y-chromosome-associated genes (figure 1A). Relative distribution of LOY was assessed, with monocytes having the greatest absolute count of LOY cells with no significant change in distribution among cell types. Given the abundance of monocytic LOY cells we investigated LOY monocytic cells transcriptional signatures (29810 Y-carrier monocytes, 2205 LOY monocytes) in an unbiased manner. Using a patient-specific, paired analysis, LOY monocytes showed significantly reduced expression of TGF-ß inhibiting genes (SMAD7, TGIF2) in LOY cells versus Y-carrier cells. Opposingly, from 193 upregulated genes, LOY cells showed elevated markers associated with monocyte/macrophage-mediated tissue damage and pro-fibrotic cardiac remodelling (S100A8, CLEC4D, TLR2). Gene ontology terms derived from upregulated genes in LOY cells further supported a mechanistic link to cardiac fibrosis by calling terms associated with TLR signaling, which are known to enhance cardiac fibrosis. (figure 1B). Conclusion This is the first study to decipher the genetic signature of LOY monocytes in HF patients. Our results considerably extend very recent experimental findings in mice that LOY sensitizes macrophages to enhanced profibrotic signaling. Diminished TGF-ß inhibitory molecules and enhanced TLR signaling may contribute to the aggravation of heart failure by LOY in patients with HF.HF mLOY scRNA-seq

An acoustic-optic comparison of fish assemblages at a Rigs-to-Reefs habitat and coral reef in the Gulf of Thailand

The number of decommissioned oil and gas platforms will increase over the coming decades. In the tropics and sub-tropics, platforms may operate near biodiverse natural habitats, such as coral reefs. Abundant and diverse fish communities often aggregate around platforms, with different decommissioning options posing variable ecological effects on these assemblages. One decommissioning option is to repurpose platforms into artificial reefs, a process commonly termed “Rigs-To-Reefs” (RTRs). Many RTR programs attempt to retain or enhance habitat availability and associated fish assemblages. To help demonstrate the importance of RTR projects, the fish habitat value of RTRs can be estimated by comparing the fish communities of RTRs to those of adjacent natural habitats. Surveying fish habitats in turbid waters necessitates the use of methods that can quantify the abundance, biomass, and length of fishes irrespective of visibility. Using an imaging sonar (1.2. MHz) and implementing a novel, pixel-based approach analogous to echo-integration, this study estimated the relative biomass density and length distribution of fishes at seven toppled oil and gas platform jackets in a Reefed Jacket Zone (RJZ) in the nearshore western Gulf of Thailand in comparison with a nearby coral reef. Biomass density was comparable at each habitat, despite extreme variability across the RJZ, attributed to the spatiotemporal stochasticity of larger, schooling fishes. However, fishes were larger at the RJZ, a trend supported by simultaneous stereo-video footage. The relative benefits and drawbacks of imaging sonar encountered in this study are also described.

PSXIII-29 Nutraceutical Effects of Fertilized and Unfertilized Sericea Lespedeza Hay on Gastrointestinal Parasitism and Whole-Plasma Metabolome of Naturally Infected Goats

Abstract The objective of this study was assessing the effect of the dietary inclusion of unfertilized (AS) and fertilized (AR) Sericea lespedeza hay on the parasitic burden, packed cellular volume (PCV), and whole-plasma metabolome of naturally infected goats. Thirty-six naturally parasite-infected (>5,000 eggs/gram) Spanish goats (23.9 ± 0.15 kg) were randomly allocated (12 goats per treatment) into three dietary treatments: a) Control (Bermudagrass hay), AS (Unfertilized lespedeza), and AR (fertilized lespedeza) for 60 days. All treatments were supplemented with a commercial concentrate following a 70:30 forage: concentrate ratio. Feed samples, blood samples, and fecal samples were collected and recorded weekly to estimate chemical composition, fecal egg counts, and PCV. Additionally, whole-plasma metabolomic analysis was performed using chemical isotope labelling/liquid chromatography-mass spectrometry-based technique. Pathway enrichment analysis and analysis of the differentially abundant metabolites were performed using MetaboAnalyst 5.0 software. Data were analyzed with the GLIMMIX procedure (repeated measures) of SAS with the fixed effect of treatment, week, and the random effect of animals. Total condensed tannins and precipitable phenolics were greater (P < 0.05) in AS compared with AR (13.9 vs. 6.5% DM; 95.3 vs.9.5 mg/g). However, both AS and AR reduced (P < 0.01) fecal egg counts compared with the control (1,100, 1,450 vs. 3,500 eggs/gram). Conversely, PCV was greater in AR compared with the control (23.6 vs. 20.6%), but no differences between AR and AS (23.6 vs. 22.5%) were observed. Compared with the control, relative distribution of glutamine and beta-leucine were increased in AS and AR. The pathway enrichment analysis revealed that dietary AS and AR increased glycine, serine, and purine metabolism compared with the control. Collectively, results from this study suggest that dietary AS and AR reduced fecal egg counts by improving anti-oxidative metabolism, muscle regeneration capacity, and immune response in naturally infected goats.

Reorganization of the mouse oocyte' cytoskeleton after cultivation under simulated weightlessness

Female germ cells provide the structural basis for the development of a new organism, while the main molecular mechanisms of the impact of weightlessness on the cell remain unknown. The aim of this work was to determine the relative content and distribution of the main proteins of microtubules and microfilaments, to assess the relative RNA content of genes in mouse oocytes after short-term exposure to simulated microgravity, and to determine the potential for embryo development up to the 3-cell stage. Before starting the study, BALB/c mice were divided into two groups. One group received water and standard food without any modifications. Before exposure to simulated microgravity, the oocytes of these animals were randomly divided into two groups – c and µg. The second group of animals additionally received essential phospholipids containing at least 80% phosphatidylcholines, per os for 6 weeks before the start of the experiment at a dosage of 350 mg/kg of the animal's body to modify the lipid composition of the oocyte membrane. The obtained oocytes of these animals were also randomly divided into two groups – ce and µge. To determine the protein distribution and its relative content, immunofluorescence analysis was performed, and the RNA content of genes was assessed using real-time PCR with reverse transcription. After cultivation under simulated microgravity, beta-actin and acetylated alpha-tubulin are redistributed from the cortical layer to the central part of the oocyte, and the relative content of acetylated alpha-tubulin and tubulin isoforms decreases. At the same time, the mRNA content of most genes encoding cytoskeletal proteins was significantly higher in comparison with the control level. The use of essential phospholipids led to a decrease in the content of cellular cholesterol in the oocyte and leveled changes in the content and redistribution of acetylated alpha-tubulin and beta-actin after cultivation under simulated microgravity. In addition, after in vitro fertilization and further cultivation under simulated weightlessness, we observed a decrease in the number of embryos that passed the stage of the 2-cell embryo, but while taking essential phospholipids, the number of embryos that reached the 3-cell stage did not differ from the control group. The results obtained show changes in the content and redistribution of cytoskeletal proteins in the oocyte, which may be involved in the process of pronucleus migration, the formation of the fission spindle and the contractile ring under simulated weightlessness, which may be important for normal fertilization and cleavage of the future embryo.

Enhanced electromagnetic wave absorption via optical fiber-like PMMA@Ti3C2Tx@SiO2 composites with improved impedance matching

Ti3C2Tx nanosheets have attracted significant attention for their potential in electromagnetic wave absorption (EWA). However, their inherent self-stacking and exorbitant electrical conductivity inevitably lead to serious impedance mismatch, restricting their EWA application. Therefore, the optimization of impedance matching becomes crucial. In this work, we developed polymethyl methacrylate (PMMA)@Ti3C2Tx@SiO2 composites with a sandwich-like core-shell structure by coating SiO2 on PMMA@Ti3C2Tx. The results demonstrate that the superiority of the SiO2 layer in combination with PMMA@Ti3C2Tx, outperforming other relative graded distribution structures and meeting the requirements of EWA equipment. The resulting PMMA@Ti3C2Tx@SiO2 composites achieved a minimum reflection loss of −58.08 dB with a thickness of 1.9 mm, and an effective absorption bandwidth of 2.88 GHz. Mechanism analysis revealed that the structural design of SiO2 layer not only optimized impedance matching, but also synergistically enhanced multiple loss mechanisms such as interfacial polarization and dipolar polarization. Therefore, this work provides valuable insights for the future preparation of high-performance electromagnetic wave absorbing Ti3C2Tx-based composites.

Inverse Identification of Drucker–Prager Cap Model for Ti-6Al-4V Powder Compaction Considering the Shear Stress State

Numerical simulation is an important method to investigate powder-compacting processes. The Drucker–Prager cap constitutive model is often utilized in the numerical simulation of powder compaction. The model contains a number of parameters and it requires a series of mechanical experiments to determine the parameters. The inverse identification methods are time-saving alternatives, but most procedures use a flat punch during the powder-compacting process. It does not reflect the densification behavior under a shearing stress state. Here, an inverse identification approach for the Drucker–Prager cap model parameters is developed by using a hemispherical punch for the powder-compacting experiment. The error between the numerical and experimental displacement–load curves was minimized to identify the Drucker–Prager cap model of titanium alloy powder. The identified model was then verified by powder-compacting experiments with the flat punch. The displacement–load curves acquired by numerical simulation were compared to the displacement–load curves obtained through experiments. The two curves are found to be in good agreement. Meanwhile, the relative density distribution of the powders is similar to the experimental results.

Development and experimental study of a scaled model for dust dispersion in fully-mechanized mining face

Model experiment is one of the research methods for the fundamental theory of coal mine dust control. To address the current deficiencies in experiment development for research on dust migration rules, a scaled model for dust dispersion in a fully-mechanized mining face was constructed based on the design prototype of the 25211 mining face at the Hongliulin mine, using a similar theory. The model includes a mining face, a return airway, a haulage roadway, and a subsidiary roadway constructed using aluminum alloy profiles and tempered glass. The model uses U-shaped exhaust ventilation. The shearer, hydraulic support, and reverse loader are equipped with dust sources, and each dust source operates independently with distinct dust generation processes that do not interfere with each other. An experimental plan for dust diffusion during shearer dust generation was designed with a wind speed of 1.0 m/s. Preliminary model experiment was conducted based on this model. The results showed that the farther away from the dust source, the lower the dust concentration. The relative mass distribution and cumulative mass distribution of falling dust particles also showed that the farther away from the dust source, the smaller the particle size of the falling dust particles. The maximum size distribution decreased from 51.4 μm to 27.9 μm, and the average particle size decreased from 34.9 μm to 20.6 μm. The test model results were validated by field tests, indicating that the constructed model has good reliability. Finally, the critical areas for future research based on this model were proposed. The development of the model provides valuable experimental support for the theory of multi-source dust transportation in the airflow on the fully-mechanized mining face.

Predicting the temperature field of thermal cloaks in homogeneous isotropic multilayer materials based on deep learning

Thermal cloaks can realize thermal manipulation and have been widely applied in the engineering field. Traditional methods, like the finite element method (FEM) and finite difference method, obtain the temperature of the thermal cloak with time-consuming. A deep learning model is proposed to predict the temperature field in homogeneous isotropic multilayer materials. The FEM is applied to solve the thermal cloak and the training data are obtained. The layer's properties, including different layers, thickness, relative thermal conductivities and distribution modes, of the thermal control or manipulative ability for temperature and heat diffusion are also investigated. The deep learning mode is developed by mapping the parameters layout to the temperature field as an image-to-image regression task and the relationship between the layer's properties and the cloaking performances is intelligently established. The temperature field of the arbitrary layout composite can be acquired almost with no time cost. The temperature field with the largest node numbers of medium temperature by the FEM and the deep learning model, is exhibited and compared. Furthermore, we extend the surrogate model to different cases with different boundary conditions, which can still achieve good prediction results. Owing to the high efficiency and complete independence from the mesh densities, the proposed method offers a novel and robust technique for predicting the temperature field and suggestion for the design of the thermal cloak.

Synthetic control of correlated disorder in UiO-66 frameworks

Changing the perception of defects as imperfections in crystalline frameworks into correlated domains amenable to chemical control and targeted design might offer opportunities for the design of porous materials with superior performance or distinctive behavior in catalysis, separation, storage, or guest recognition. From a chemical standpoint, the establishment of synthetic protocols adapted to control the generation and growth of correlated disorder is crucial to consider defect engineering a practicable route towards adjusting framework function. By using UiO-66 as experimental platform, we systematically explored the framework chemical space of the corresponding defective materials. Periodic disorder arising from controlled generation and growth of missing cluster vacancies can be chemically controlled by the relative concentration of linker and modulator, which has been used to isolate a crystallographically pure “disordered” reo phase. Cs-corrected scanning transmission electron microscopy is used to proof the coexistence of correlated domains of missing linker and cluster vacancies, whose relative sizes are fixed by the linker concentration. The relative distribution of correlated disorder in the porosity and catalytic activity of the material reveals that, contrarily to the common belief, surpassing a certain defect concentration threshold can have a detrimental effect.