An all-Mach number HLLC-based scheme for multi-phase flow with surface tension

This paper presents an all-Mach method for two-phase inviscid flow in the presence of surface tension. A modified version of the Hartens–Lax–van Leer Contact (HLLC) solver is developed and combined for the first time with a widely used volume-of-fluid (VoF) method: the compressive interface capturing scheme for arbitrary meshes (CICSAM). This novel combination yields a scheme with both HLLC shock capturing as well as accurate liquid–gas interface tracking characteristics. It is achieved by reconstructing non-conservative (primitive) variables in a consistent manner to yield both robustness and accuracy. Liquid–gas interface curvature is computed via height functions and the convolution method. We emphasize the use of VoF in the interest of interface accuracy when modelling surface tension effects. The method is validated using a range of test-cases available in the literature. The results show flow features that are in sensible agreement with previous experimental and numerical work. In particular, the use of the HLLC-VoF combination leads to a sharp volume fraction and energy field with improved accuracy

A comparison of warm and combined warm and low temperature processing routes for the equal-channel angular pressing of pure titanium.

Two different processing routes were used to investigate the microstructure and strength of commercial purity (CP) titanium of grade 4 processed by equal-channel angular pressing (ECAP). In the combined temperature (CT) route the specimens were pressed at 723 K in the first pass and at 373 K in the second pass but in the warm temperature (WT) route the specimens were pressed through two passes at 723 K. Both routes led to an inhomogeneous microstructure with average grain sizes of ~1.5 and ~1.7 um after the CT and WT routes, respectively. Both routes gave improved strengthening and higher hardness but the CT route with a lower temperature step gave the highest ultimate tensile strength of ~790 MPa. The inclusion of a lower temperature processing step may be important for optimizing the strength of CP Ti for use in medical implants

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Structural Ceramics

No abstract provided

The potential of chironomid (Insecta: Diptera) larvae in archaeological investigations of floodplain and lake settlements

The head capsules of chironomids (Insecta: Diptera) are well preserved in sediments and can be recognised to a high taxonomic level, usually genus and sometimes species. Work on lake sediments has shown that they can be accurate indicators of water temperature, oxygen regimes, and nutrient status (particularly total phosphorus and chlorophyll-a), as well as heavy metal pollution. No systematic chironomid analyses, however, have previously been undertaken on archaeological deposits. In order to address this we assessed the use of chironomids in three types of archaeological deposit; firstly, a lake core at the edge of a lake settlement (crannog), secondly, a palaeochannel infill adjacent to a multi-period settlement site and lastly, a Roman well deposit from a floodplain environment. The chironomid assemblages are shown to vary significantly both between and within the sites and reflect the immediate environment and the adjacent area. The lake sediment assemblage reflects the construction of the crannog through elevated levels of organic detritus, wood and woody debris. The palaeochannel assemblage reveals changing natural conditions and nutrient enrichment probably associated with settlement during the Saxon period. The well assemblage is taxonomically restricted and indicative of organic debris, dead plant material, animal dung and possibly human effluent deposited after abandonment of the well. Dry storage of the palaeochannel and well sediments for several years did not appear to affect the concentration or state of preservation of the head capsules. The chironomid reconstructions are shown to provide an additional indicator of human activity which has the potential to provide quantitative data on the character of aquatic environments associated with archaeological sites

Regional climate change from peat stratigraphy for the mid- to late Holocene in central Ireland

At the millennial scale bog surface wetness (BSW) records show a clear Holocene climate event stratigraphy,with major phases comparable with other regional climate proxies such as chironomid inferredtemperature records. Moving towards the centennial scale, however, and towards the limits of chronologicalcertainty within the records, regional differences are apparent which likely reflect the moreheterogeneous precipitation patterns which occur on shorter timescales. The BSW data presented in thispaper are reconstructed from testate amoebae assemblages from central Ireland and are compared withother regional records. The results suggest that this region is in phase with the North of Ireland in termsof timings and durations of climate change, but the comparisons are less clear with a stacked and tunedrecord from Northern Britain that shows an apparent offset compared to the Irish records. This mayreflect variations in past regional precipitation or be a function of the tuning and stacking process. Thebroad phases of comparison between the Irish records, and the extension of the central Irish record backto 6000 cal BP, allow comparisons with low frequency temperature reconstructions from chironomids,which also show a broad level of correlation, with cooler temperatures relating to wetter BSW atcentennial to millennial timescales

A sediment-based multiproxy palaeoecological approach to the environmental archaeology of lake dwellings (crannogs), Central Ireland

A multiproxy study of Ballywillin Crannog, Lough Kinale, central Ireland is presented. The methodology used reveals the wealth of information that a multiproxy approach can contribute in lake settlement studies. Plant macrofossils, pollen and spores, diatoms, chironomids and Coleoptera from a lake core are used to reconstruct local and regional vegetation change and lake history to establish the age and function of the crannog. The palaeoecological evidence suggests that Ballywillin Crannog was constructed around AD620, with its most intensive period of occupation after AD1150. Cereals and a range of gathered fruits and nuts were brought onto and cooked on the crannog, and cereal grains were possibly stored there

Mechanical properties and microstructure of AZ31B magnesium alloy processed by I-ECAP

Incremental equal channel angular pressing (I-ECAP) is a severe plastic deformation process used to refine grain size of metals, which allows processing very long billets. As described in the current article, an AZ31B magnesium alloy was processed for the first time by three different routes of I-ECAP, namely, A, Bc, and C, at 523 K (250 °C). The structure of the material was homogenized and refined to ~5 microns of the average grain size, irrespective of the route used. Mechanical properties of the I-ECAPed samples in tension and compression were investigated. Strong influence of the processing route on yield and fracture behavior of the material was established. It was found that texture controls the mechanical properties of AZ31B magnesium alloy subjected to I-ECAP. SEM and OM techniques were used to obtain microstructural images of the I-ECAPed samples subjected to tension and compression. Increased ductility after I-ECAP was attributed to twinning suppression and facilitation of slip on basal plane. Shear bands were revealed in the samples processed by I-ECAP and subjected to tension. Tension–compression yield stress asymmetry in the samples tested along extrusion direction was suppressed in the material processed by routes Bc and C. This effect was attributed to textural development and microstructural homogenization. Twinning activities in fine- and coarse-grained samples have also been studied