A study into the effect of cleat demineralisation by hydrochloric acid on the permeability of coal

Mineral occlusions in cleats are known to considerably reduce coal permeability. Sequential steady state core flooding experiments with aqueous hydrochloric acid (HCl) solutions were conducted on whole core samples from the Bowen Basin, Australia, to assess the effect of mineral dissolution on core permeability. Cleat minerals were characterised by scanning electron microscopy with energy dispersive x-ray spectroscopy (SEM-EDS). Generally, the cleats contained kaolinite and carbonates which were present in various proportions as either single phases or mixed. An immediate increase in permeability was obtained after HCl was flooded through for the majority of tests. This increase coincided with heightened concentrations of Ca and Fe in the effluent and is attributed to the dissolution of acid soluble minerals, mainly calcite and siderite. In some cases the increase in permeability was very high (200 times increase) and sustained whilst in other cases there was a gradual decrease after the initial increase, resulting in either a small overall increase in permeability of about 20–30% or a decline in permeability relative to the original level of about 20–30%. A possible reason for permeability decline is that although dissolution of minerals allows more liquid into the core, it is not enhancing flow paths, i.e. restrictions to flow in the cleats still exist. Another reason could be destabilisation of insoluble minerals, causing them to become mobile fines in the liquid which migrate toward restrictions in the flow and then jam. High and sustained permeability increases are attributed to cleats containing solely calcite in addition to having high connectivity. This investigation has shown that cleat demineralisation using HCl can be an effective means to overcome low permeability provided cleat connectivity and mineralogy are characterised

Heritable Factors Play a Major Role in Determining Host Responses to \u3ci\u3eWuchereria bancrofti\u3c/i\u3e Infection in an Isolated South Pacific Island Population

Background. It is increasingly recognized that host genetic factors may play an important role in determining the outcome of filarial infections. To test this hypothesis in bancroftian lymphatic filariasis, pedigree data were collected twice during an 18-year period from an isolated Polynesian population living on a Pacific island where lymphatic filariasis is endemic. Methods. Using variance-component analysis, we examined the contribution of shared genetic and environmental effects on host clinical and immune responses to filarial infection, along with potential confounding determinants. Results. Sex was found to have a negligible influence on heritability estimates, but shared-household effects accounted for up to 32% of host variability. After accounting for these shared-household effects, heritability estimates suggested that levels of microfilariae and circulating adult worm antigen, as well as host eosinophil and immunoglobulin G antibody responses to larval and adult worm antigens, were highly heritable (range of heritability estimates, 0.15-0.84). Conclusions. These data provide evidence of a key role for genetic factors in determining the host response to filarial infections in humans and emphasize the complexity of the relationships among the host, parasite, and environment

The acquisition of mechano-electrical transducer current adaptation in auditory hair cells requires myosin VI

Mutations in Myo6, the gene encoding the (F-actin) minus end-directed unconventional myosin, myosin VI, cause hereditary deafness in mice (Snell's waltzer) and humans. In the sensory hair cells of the cochlea, myosin VI is expressed in the cell bodies and along the stereocilia that project from the cells’ apical surface. It is required for maintaining the structural integrity of the mechanosensitive hair bundles formed by the stereocilia. In this study we investigate whether myosin VI contributes to mechano-electrical transduction. We report that Ca²+-dependent adaptation of the mechano-electrical transducer (MET) current, which serves to keep the transduction apparatus operating within its most sensitive range, is absent in outer and inner hair cells from homozygous Snell's waltzer mutant mice, which fail to express myosin VI. The operating range of the MET channels is also abnormal in the mutants, resulting in the absence of a resting MET current. We found that cadherin 23, a component of the hair bundle's transient lateral links, fails to be downregulated along the length of the stereocilia in maturing Myo6 mutant mice. MET currents of heterozygous littermates appear normal. We propose that myosin VI, by removing key molecules from developing hair bundles, is required for the development of the MET apparatus and its Ca²+-dependent adaptation

Significance of effective lubrication in mitigating system failures: a wind turbine gearbox case study.

The effectiveness of lubrication in machines mainly depends on the physical and chemical properties of lubricating oil, like quantity, level of suspended particles, effect of external load/shear forces, temperature amongst others. Periodic inspection of lubricating oil for its grade of viscosity, H2O content, fuel content, amount and nomenclature of suspended particles etc. assists maintenance personal in assessing the quality of oil and its residual life. Such assessments are also useful in determining health of the system in which the lubricating oil was used. This work discusses about industrial Wind Turbine Gearbox lubrication, its importance, applications, oil analysis method and lists constituents found in the oil. Results lead us to the conclusion that additives in the oil protect the gearbox from wear and tear during initial years of operation. Analysis also suggests that re-lubrication process should be performed every 18 months time interval to optimise the life of gearbox components. Other results and advice for lubrication are also listed

A SMART software package for maintenance optimisation of offshore wind turbines.

Offshore Wind Turbine (OWT) maintenance costs in between 20 - 35% of the lifetime power generation cost. Many techniques and tools that are being developed to curtail this cost are challenged by the stochastic climatic conditions of offshore location and the wind energy market. A generic and OWT centric software packages that can smartly adapt to the requirement of any offshore wind farm and optimise its maintenance, logistics and spares-holding while giving due consideration to offshore climate and market conditions will enable OWT operators to centralise their operation and maintenance planning and make significant cost reductions. This work aims to introduce the idea of a comprehensive tool that can meet the above objectives, and give examples of data and functions required. The package uses wind turbine condition monitoring data to anticipate component failure and proposes a time and maintenance implementation strategies that is developed as per the requirements of HSE and government regulations for working in the offshore locations and at heights. The software database contains key failure analysis data that will be an invaluable asset for future researchers, turbine manufacturers and operators, that will optimise OWT power generation cost and better understand OWT working. The work also lists some prevalent tools and techniques developed by industries and researchers for the wind industry

Assembly of Bacterial Genome Sequences from Metagenomes of Spacecraft Assembly Cleanrooms

Characterizing the microbiome of spacecraft assembly cleanrooms is important for planetary protection. We report two bacterial metagenome-assembled genomes (MAGs) reconstructed from metagenomes produced from cleanroom samples from the Kennedy Space Center’s Payload Hazardous Servicing Facility (KSC-PHSF) during the handling of the Phoenix spacecraft. Characterization of these MAGs will enable identification of the strategies underpinning their survival