Multi-seam mining-induced subsidence profile is observed to be different from that of single-seam mining. Understanding the characteristics of multi-seam subsidence is the first step in achieving ...reliable subsidence predictions. Characteristics of multi-seam subsidence are investigated by means of several sand-plaster physical models. Geological and site specific parameters are kept constant in all the models in order to compare the multi-seam subsidence parameters for different mining configurations. Based on observations from the physical models, it is concluded that the panel configurations of the two seams have significant impact on the multi-seam subsidence development. Based on the relative location of the panels the multi-seam mine area can be divided into different zones, to which suitable subsidence characteristics can be assigned. Dividing the mine area into different zones enables characterisation of the strata movement and multi-seam subsidence for various multi-seam configurations. The proposed characterisation of the multi-seam subsidence can also be utilised in subsidence prediction methods in order to achieve reliable prediction results.
•Physical modelling is used to investigate multi-seam subsidence characteristics.•Effects of different mining configurations on subsidence profile are investigated.•The multi-seam subsidence is characterised based on the physical modelling results.•The proposed characterisation can be employed in subsidence prediction methods.
Palladium membranes used for hydrogen separation seemingly develop cavities filled with hydrogen, i.e. hydrogen bubbles, along the grain boundaries. These bubbles may represent initial stages of ...pinhole formation that lead to unselective leakage and compromise the long-term stability of the membranes. Alloying with Ag improves the permeability of Pd, but whether these H2 bubbles form in Pd-Ag membranes remained unknown. In this work, the microstructure of a Pd77Ag23 membrane was characterized by electron microscopy after H2 permeation testing for 50 days at 15 bar at temperatures up to 450 °C. The results show that Ag does not prevent bubbles from emerging along high-angle grain boundaries, but reduces the number of potential nucleation sites for cavity formation by supressing the development of dislocation networks when H-saturated Pd is cycled through the miscibility gap. Both magnetron-sputtered and electroless plated membranes are afflicted by H2 bubbles, thus their formation seems determined by intrinsic properties of the material independent of the fabrication technique. The qualitative discussion enables to point directions for enhancement of membrane stability.
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•The microstructure of a Pd77Ag23 membrane was characterized by electron microscopy.•Palladium membranes develop hydrogen bubbles along the grain boundaries.•The bubble formation seems independent of the fabrication technique.•The cavities may represent the origin of pinhole formation.
Microplastics have been found in all marine ecosystems, raising concern about their potential environmental impacts. Yet relatively little research has focused on surface characteristics, compared to ...polymer type. The aim of this review is to discuss the importance of microplastic surface properties and how expanded characterisation and more detailed quantification can aid in assessing their behaviours in aquatic environments. Concepts including surface roughness, formation of surface ecocoronae and sorptive behaviours of microplastic surfaces are discussed. To address these concepts, three exemplary methods are introduced and their application to the study of microplastic surfaces discussed with the following recommendations; atomic force microscopy should be explored for conducting physical surface characterisation and to examine surface roughness; double-shot Pyrolysis-Gas Chromatography–Mass Spectroscopy should be considered for examining microplastic sorption behaviours in multi-solute media; and finally, Whispering Gallery Mode nanosensing techniques should be explored as a potential means to generate data on microplastic sorption kinetics.
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•Atomic force microscopy could expand physical characterisation of microplastics.•A variation on double-shot Py-GCMS could advance research into ecocorona formation.•Whispering gallery mode methods may enable study of surface interaction kinetics.
The total aerobe micro flora can be determined on solid mediums for the aerobe bacteria and this relive quantity of micro organisms from the peat samples. The quantitative evaluation was done using ...solid nutritive mediums which allows the estimation of nr CFU/g as well observing the morphology of the colonies and their utility through their emplacement and morphological and biochemical characterization of isolated strains.. The evaluations where done through the method of dilution, using selective liquid mediums. Every day the characteristic reaction of the respective group was observed, either through the metabolising of the substrate, or through the appearance of a catabolic product in the medium.
•Methods for spatial drought tracking and characterisation are presented: S-TRACK and DDRASTIC-spatial.•Drought tracking involves identification of areas (clusters), centroids localisation, and ...centroids linkage.•Drought paths are defined by an onset and an end in space and time.•S-TRACK method is applied for the calculation of extreme droughts.
The spatiotemporal monitoring of droughts is a complex task. In the past decades, drought monitoring has been increasingly developed, while the consideration of its spatio-temporal dynamics is still a challenge. This study proposes a method to build the spatial tracks and paths of drought, which can enhance its monitoring. The steps for the drought tracks calculation are (1) identification of spatial units (areas), (2) centroids localisation, and (3) centroids linkage. The spatio-temporal analysis performed here to extract the areas and centroids builds upon the Contiguous Drought Area (CDA) analysis. The potential of the proposed methodology is illustrated using grid data from the Standardized Precipitation Evaporation Index (SPEI) Global Drought Monitor over India (1901-2013), as an example. The method to calculate the drought tracks allows for identification of drought paths delineated by an onset and an end in space and time. Tracks, severity and duration of the drought are identified, as well as localisation (onset and end position), and rotation. The response of the drought tracking method to different combinations of parameters is also analysed. Further research is in progress to set up a model to predict the drought tracks for particular regions across the world, including India (https://www.researchgate.net/project/STAND-Spatio-Temporal-ANalysis-of-Drought).
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Hyaluronidase (HAase) can enhance drug diffusion and dissipate edema by degrading hyaluronic acid (HA) in the extracellular matrix into unsaturated HA oligosaccharides in mammalian tissues. ...Microorganisms are recognized as valuable sources of HAase. In this study, a new hyaluronate lyase (HAaseD) from Bacillus sp. CQMU-D was expressed in Escherichia coli BL21, purified, and characterized. The results showed that HAaseD belonged to the polysaccharide lyase (PL) 8 family and had a molecular weight of 123 kDa. HAaseD could degrade chondroitin sulfate (CS) -A, CS-B, CS-C, and HA, with the highest activity toward HA. The optimum temperature and pH value of HAaseD were 40℃ and 7.0, respectively. In addition, HAaseD retained stability in an alkaline environment and displayed higher activity with appropriate concentrations of metal ions. Moreover, HAaseD was an endolytic hyaluronate lyase that could degrade HA to produce unsaturated HA oligosaccharides. Together, our findings indicate that HAaseD from Bacillus sp. CQMU-D is a new hyaluronate lyase and with excellent potential for application in industrial production.
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