Centrifuge modelling of the initiation of cracks in a clay liner subjected to differential settlement with and without overburden pressure

Compacted clay liners are used in the basal and capping layers of landfills to separate the waste material from the environment. These liners are subjected to differential settlement through degradation of the waste or compression of the subgrade. This differential settlement induces cracking in the liner, and reduces the effectiveness of the clay as an en vironmental protection barrier. P hysical model tests were conducted in the geotechnical centrifuge to study the influence of differential settlement on clay liners and observe the crack mechanism using a consolidated kaolin clay beam to model the clay liner . Differential settlement was imposed on the clay beam by means of a trapdoor. Cracking in the clay was monitored through digital analysis of images taken as the tests were conducted using particle image velocimetry. The test investigate d the orientation and types of cracks formed with varying void dimensions and with and without overburden pressure The unconfined clay over the small trapdoor was able to support itself across the void; a punching shear failure occurred in the case of a wider trapdoor or greater overburden pressure

Holocene vegetation dynamics of the Eastern Mediterranean region: old controversies addressed by a new analysis

Aim: We reconstruct vegetation changes since 12 ky in the Eastern Mediterranean to examine four features of the regional vegetation history that are controversial: the extent of non-analogue vegetation assemblages in the transition from the Late Glacial to the early Holocene, the synchroneity of postglacial forest expansion, the geographical extent of temperate deciduous forest during the mid-Holocene and the timing and trigger for the re-establishment of drought-tolerant vegetation during the late Holocene. Location: The Eastern Mediterranean–Black Sea Caspian Corridor. Taxon: Vascular plants. Methods: We reconstruct vegetation changes for 122 fossil pollen records using a method that accounts for within-biome variability in pollen taxon abundance to determine the biome with which a sample has greatest affinity. Per-biome affinity threshold values were used to identify samples that do not belong to any modern biome. We apply time series analysis and mapping to examine space and time changes. Results: Sites with non-analogue vegetation were most common between 11.5 and 9.5 ky and mostly in the Carpathians. The transition from open vegetation to forest occurred at 10.64 ± 0.65 ky across the whole region. Temperate deciduous forest was not more extensive at 6 ky; maximum expansion occurred between 5.5 and 5 ky. Expansion of forest occurred between c. 4 and 2.8 k, followed by an abrupt decrease and a subsequent recovery. This pattern is not consistent with a systematic decline of forest towards more drought-tolerant vegetation in the late Holocene but is consistent with centennial-scale speleothem patterns linked to variations in moisture availability. Main Conclusions: We show the occurrence of non-analogue vegetation types peaked during early Holocene, forest expansion was synchronous across the region and there was an expansion of moisture-demanding temperate trees around 5.5 to 5 ky. There is no signal of a continuous late Holocene aridification, but changes in forest cover appear to reflect climatic rather than anthropogenic influences

Terminomics methodologies and the completeness of reductive dimethylation: A meta-analysis of publicly available datasets

© 2019 by the authors. Methods for analyzing the terminal sequences of proteins have been refined over the previous decade; however, few studies have evaluated the quality of the data that have been produced from those methodologies. While performing global N-terminal labelling on bacteria, we observed that the labelling was not complete and investigated whether this was a common occurrence. We assessed the completeness of labelling in a selection of existing, publicly available N-terminomics datasets and empirically determined that amine-based labelling chemistry does not achieve complete labelling and potentially has issues with labelling amine groups at sequence-specific residues. This finding led us to conduct a thorough review of the historical literature that showed that this is not an unexpected finding, with numerous publications reporting incomplete labelling. These findings have implications for the quantitation of N-terminal peptides and the biological interpretations of these data

Improved nanocomposite of montmorillonite and hydroxyapatite for defluoridation of water

A novel hydroxyapatite montmorillonite (HAP-MMT) nanocomposite system was synthesized using a simple wet chemical in situ precipitation method. Neat nano hydroxyapatite (HAP) was also synthesized for comparison. The characterization of the materials was carried out using Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and Brunauer–Emmett–Teller (BET) isotherms to study the functional groups, morphology, crystallinity and the surface area respectively. Batch adsorption studies and kinetic studies on fluoride adsorption were conducted for the HAP-MMT system and for neat HAP. The effect of parameters such as contact time, pH, initial concentration, temperature, and thermodynamic parameters and the effect of coexisting ions on fluoride adsorption by HAP-MMT were studied. Results of the isotherm experiments were fitted to four adsorption isotherm models namely Langmuir, Freundlich, Temkin and Dubinin Radushkevich. Fluoride adsorption over HAP-MMT fitted to the Freundlich adsorption isotherm model and showed more than two-fold improved adsorption capacity (16.7 mg g−1) compared to neat HAP. The best-fitting kinetic model for both adsorbents was found to be pseudo second order. Calculated thermodynamic parameters indicated that the fluoride adsorption by HAP-MMT is more favorable compared to that on HAP within the temperature range of 27 °C–60 °C. Improved fluoride adsorption by HAP-MMT is attributed to the exfoliated nature of HAP-MMT. Gravity filtration studies carried out using a 1.5 ppm fluoride solution, which is closer to the ground water fluoride concentrations of Chronic Kidney Disease of unknown etiology (CKDu) affected areas in Sri Lanka, resulted in a 1600 ml g−1 break through volume indicating the potential of HAP-MMT to be used in real applications

A NEW METHODOLOGY FOR DIAGNOSIS OF FANCONI ANEMIA BASED ON BIOLOGICAL DOSIMETRY

Fanconi Anemia (FA) is a syndrome associated with chromosomal fragility. Current laboratory tests to diagnose this disease are based on the scoring of chromosomal aberrations induced in peripheral blood lymphocytes by clastogenic chemical agents, mainly: diepoxybutane (DEB) or mitomycin C (MMC). This study evaluated an alternative test for the diagnosis of FA, in which ionizing radiation replaces DEB/MMC. Two groups were studied: normal and DEB-sensitive individuals. From each individual, samples of peripheral blood were irradiated using an electron linear accelerator. Following lymphocyte cultures, and slide preparation, metaphases were scored based on the same methodology for biological dosimetry, according to recommendations of the International Atomic Energy Agency. Our results emphasized a pattern of distribution of dicentrics, fragments, as well as abnormal chromosomal arrangements. The methodology of analysis here proposed permitted to distinguish normal from DEB-sensitive subjects

Examining the extent of repeat and near repeat victimisation of domestic burglaries in Belo Horizonte, Brazil

Substantial research suggests that a burglary event is a useful predictor of burglaries to the same or nearby properties in the near future. To date, the research that has suggested this predictive quality has been based on studies that have focused on crime patterns in western industrialised countries, such as the UK, USA and Australia. These studies have in turn informed the design of effective burglary reduction programmes that have a specific focus towards countering the risk of repeats and near repeats. This current study adds to the existing research knowledge by examining whether patterns of burglary repeats and near repeats are evident in Belo Horizonte, a large Brazilian city. Domestic dwellings in Brazilian cities, as typified by those in Belo Horizonte, are quite different to dwellings in western countries—many city-dwelling Brazilians live in apartments in high rise buildings, most houses and apartment blocks are surrounded by high perimeter fencing, and a reasonable proportion of dwellings are irregular self-constructed houses. As a consequence, a different infrastructure of domestic living may result in differences in patterns of domestic burglary when compared to patterns in western countries. The research identifies that the extent of repeat and near repeat patterns in the city of Belo Horizonte are lower than those in comparable western urban contexts. We discuss the implications of these findings and how they impact on the translating of practice on crime prevention and crime prediction to the urban Latin American context

Relationship of Participation Pregnant Women in The Pregnant Classes with Anxiety in The Working Area of Oelolok Health Service Centre, North Central Timor Regency

Anxiety during pregnancy is caused by fear. Fear of increased pain, fear of damage or deformity such as episiotomy, rupture, stitches or cesarean section, and mothers fear injuring their babies. The mother's knowledge factor in dealing with childbirth is a very important factor affecting the smoothness of the birth process. The purpose of this study was to determine whether there was a relationship between the participation of pregnant women in the pregnant class and the level of anxiety in facing childbirth among pregnant women in the working area of ​​the Oelolok Puskesmas. The study design used in this study was a quasi-experimental model. There is a relationship between the participation of pregnant women in pregnancy classes and the level of anxiety in facing childbirt

Improving the Creation of Hot Spot Policing Patrol Routes: Comparing Cognitive Heuristic Performance to an Automated Spatial Computation Approach

Hot spot policing involves the deployment of police patrols to places where high levels of crime have previously concentrated. The creation of patrol routes in these hot spots is mainly a manual process that involves using the results from an analysis of spatial patterns of crime to identify the areas and draw the routes that police officers are required to patrol. In this article we introduce a computational approach for automating the creation of hot spot policing patrol routes. The computational techniques we introduce created patrol routes that covered areas of higher levels of crime than an equivalent manual approach for creating hot spot policing patrol routes, and were more efficient in how they covered crime hot spots. Although the evidence on hot spot policing interventions shows they are effective in decreasing crime, the findings from the current research suggest that the impact of these interventions can potentially be greater when using the computational approaches that we introduce for creating hot spot policing patrol routes