76 research outputs found

    Standards of practice in forensic age estimation with CT of the medial clavicular epiphysis-a systematic review.

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    The AGFAD (Arbeitsgemeinschaft für Forensische Alterdiagnostik, Study Group on Forensic Age Diagnostics) has published several recommendations regarding both technical aspects of computed tomography (CT) of the medial clavicular epiphysis (MCE) and the process of reading and interpreting the CT images for forensic age estimations (FAE). There are, however, no published recommendations regarding CT scan protocols and no dose reference values for CT of the MCE. The objective of this analysis was to assess adherence to AGFAD recommendations among practitioners of FAE and analyse reported dose-relevant CT scan parameters with the objective of helping to establish evidence-based dose reference values for FAE. A systematic literature search was conducted in PubMed and in Google Scholar with specific MeSH terms to identify original research articles on FAE with CT of the MCE from 1997 to 2022. A total of 48 studies were included. Adherence to AGFAD recommendations among practitioners of FAE is high regarding the use of Schmeling main stages (93%), bone window (79%), ≤ 1 mm CT slices (67%), axial/coronal CT images (65%), and Kellinghaus sub-stages (59%). The reporting of CT technique and CT dose-relevant scan parameters is heterogeneous and often incomplete in the current literature. Considering the success achieved by the AGFAD in creating standards of practice of FAE in living subjects, there is potential for the AGFAD to establish standards for radiation protection in FAE as well

    Thermal behaviour and microstructure evolution of new ternary eutectic alloy in Al-Cu-Si-Ni system

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    Data availability: The authors do not have permission to share data.Appendix A. Supplementary material: Word document (1MB) available online at https://www.sciencedirect.com/science/article/pii/S0925838823002451?via%3Dihub#sec0065 .Copyright © 2023 The Author(s). Eutectic alloys were fabricated from the quaternary Al-Cu-Si-Ni system via arc melting and suction casting. An invariant ternary eutectic reaction (α-Al+Si+θ-Al2(CuNi)) was found in the quaternary alloy system with a composition of Al67.2Cu24Si8Ni0.8 (wt.%). The dissolution of Ni (~1.7 at.%) into tetragonal θ-Al2Cu takes place during this ternary eutectic reaction. Density functional theory (DFT) calculations show that the configurational entropy stabilises this level of randomly substituted Ni with Cu sites in the θ-Al2Cu lattice at high temperatures. The as-solidified eutectic microstructure exhibits a lamellar θ-Al2(CuNi) phase showing fragmented lamellar morphology with a lamellar thickness of 130±30 nm and Si exhibits fibrous morphology with a fibre diameter below 100 nm. The thermal stability of the Al-Cu-Si-Ni eutectic alloy after post-solidification annealing was investigated, and the thermal stability of the ternary eutectic microstructure is better than the corresponding Al33Cu (wt.%) binary eutectic microstructure. It was found that Ni solution in θ-Al2(CuNi) phase contributes to the thermal stability of this ternary eutectic microstructure and β2-Al3(CuNi)2 (β1-(Cu2.9Ni0.1)Al type, Fm-3m) phase can transform from θ-Al2(CuNi) phase after annealing at different temperatures. The Al-Cu-Si-Ni eutectic alloy has excellent as-cast hardness together with thermal stability. It is potentially valuable for the design of new aluminium alloys for serving at elevated temperatures.Engineering and Physical Sciences Research Council (EPSRC) for the financial support on Future Liquid Metal Engineering (LiME) Hub (EP/N007638/1)

    A novel Al-Si-Ni-Fe near-eutectic alloy for elevated temperature applications

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    Supplementary materials are available online at https://www.sciencedirect.com/science/article/pii/S135964622300430X?via%3Dihub#sec0002 .Copyright © 2023 The Authors. A novel near-eutectic Al-15.0Si-4.1Ni-1.9Fe (wt%) alloy with a ternary eutectic reaction of Liquid→α-Al+Si+(Al,Si)5(Fe,Ni) was investigated. Eutectic Si and (Al,Si)5(Fe,Ni) phases exhibit short nanoscale fibrous morphologies with volume fractions of 14.3 ± 1.6% and 15.1 ± 1.9%, respectively. The (Al,Si)5(Fe,Ni) phase has a tetragonal Al2.7FeSi2.3-type crystal structure with excellent thermal stability, which contributes to high mechanical properties at room and elevated temperatures. First-principles density-functional theory (DFT) calculations reveal its chemical composition of tetragonal (Al4.75Si0.25)(Fe0.5Ni0.5) having Si solution at the Al sites with two Fe neighbours contributes to the lowest solution energy. The newly developed alloy has superior mechanical properties at room and elevated temperatures compared with other typical heat-resistant aluminium alloys, which has great potential for industrial applications.Engineering and Physical Sciences Research Council (EPSRC) under grant Future Liquid Metal Engineering (LiME) Hub (EP/N007638/1)

    Non-Water-Suppressed 1H MR Spectroscopy with Orientational Prior Knowledge Shows Potential for Separating Intra- and Extramyocellular Lipid Signals in Human Myocardium

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    Conditions such as type II diabetes are linked with elevated lipid levels in the heart, and significantly increased risk of heart failure; however, metabolic processes underlying the development of cardiac disease in type II diabetes are not fully understood. Here we present a non-invasive method for in vivo investigation of cardiac lipid metabolism: namely, IVS-McPRESS. This technique uses metabolite-cycled, non-water suppressed 1H cardiac magnetic resonance spectroscopy with prospective and retrospective motion correction. High-quality IVS-McPRESS data acquired from healthy volunteers allowed us to investigate the frequency shift of extramyocellular lipid signals, which depends on the myocardial fibre orientation. Assuming consistent voxel positioning relative to myofibres, the myofibre angle with the magnetic field was derived from the voxel orientation. For separation and individual analysis of intra- and extramyocellular lipid signals, the angle myocardial fibres in the spectroscopy voxel take with the magnetic field should be within ±24.5°. Metabolite and lipid concentrations were analysed with respect to BMI. Significant correlations between BMI and unsaturated fatty acids in intramyocellular lipids, and methylene groups in extramyocellular lipids were found. The proposed IVS-McPRESS technique enables non-invasive investigation of cardiac lipid metabolism and may thus be a useful tool to study healthy and pathological conditions

    Microstructure and Mechanical Properties of Ultrafine Quaternary Al-Cu-Si-Mg Eutectic Alloy

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    Copyright: © 2021 by the authors. The microstructure evolution and mechanical properties of quaternary Al-Cu-Si-Mg eutectic alloy prepared via arc melting and suction casting were studied. This alloy exhibits a single endothermic DSC peak with a melting temperature of 509 °C upon heating, suggesting a eutectic reaction. The cast alloy microstructure consisted of four phases, α-Al, Al2Cu (θ ), Si and Al4Cu2Mg8Si7 (Q), in the eutectic cells and also in the nano-scale anomalous eutectic in the intercellular regions. The eutectic cells show different morphologies in different parts of the sample. Well-defined orientation relationships between the α-Al, Al2Cu, and Q phases were found in the eutectic cell centres, while decoupled growth of Q phase occurred at the cell boundaries. The bimodal microstructure exhibits excellent compressive mechanical properties, including a yield strength of 835 ± 35 MPa, a fracture strength of ~1 GPa and a compressive fracture strain of 4.7 ± 1.1%. The high strength is attributed to a combination of a refined eutectic structure and strengthening from multiple hard phases.Engineering and Physical Sciences Research Council (EPSRC) for the financial support on Future Liquid Metal Engineering (LiME) Hub (EP/N007638/1)

    Seismic evidence for a lower-mantle origin of the Iceland plume

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    Iceland, one of the most thoroughly investigated hotspots1,2,3, is generally accepted to be the manifestation of an upwelling mantle plume4. Yet whether the plume originates from the lower mantle or from a convective instability at a thermal boundary layer between the upper and lower mantle near 660 km depth5,6 remains unconstrained. Tomographic inversions of body-wave delay times show that low seismic velocities extend to at least 400 km depth beneath central Iceland7,8, but cannot resolve structure at greater depth. Here we report lateral variations in the depths of compressional-to-shear wave conversions at the two seismic discontinuities marking the top and bottom of the mantle transition zone beneath Iceland. We find that the transition zone is 20 km thinner than in the average Earth9 beneath central and southern Iceland, but is of normal thickness beneath surrounding areas, a result indicative of a hot and narrow plume originating from the lower mantle.This work was supported by the US NSFPeer Reviewe

    Clients’ satisfaction with quality of childbirth services: A comparative study between public and private facilities in Limuru Sub-County, Kiambu, Kenya

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    Background: This study intended to compare the clients’ satisfaction with the quality of childbirth services in a private and public facility amongst mothers who have delivered within the last twenty four to seventy hours. Methods: This was a cross-sectional comparative research design with both quantitative and qualitative data collection and analysis methods. Data were collected through a focused group discussion guide and structured questionnaire collecting information on clients’ satisfaction with quality of childbirth services. The study was conducted amongst women of reproductive age (WRA) between 15-49 years in Tigoni District hospital (public hospital) and Limuru Nursing home (private hospital). For quantitative data we conducted descriptive analysis and Mann-Whitney test using SPSS version 20.0 while qualitative data was manually analyzed manually using thematic analysis. Results: A higher proportion of clients from private facility 98.1% were attended within 0-30 minutes of arrival to the facility as compared to 87% from public facility. The overall mean score showed that the respondents in public facility gave to satisfaction with the services was 4.46 out of a maximum of 5.00 score while private facility gave 4.60. The level of satisfaction amongst respondents in the public facility on pain relief after delivery was statistically significantly higher than the respondents in private facilities (U=8132.50, p<0.001) while the level of satisfaction amongst respondents in the public facility on functional equipment was statistically significantly higher than the respondents in private facilities (U=9206.50, p=0.001). Moreover, level of satisfaction with the way staff responded to questions and concerns during labour and delivery was statistically significantly higher than the respondents in private facilities (U=9964.50, p=0.022). Conclusion: In overall, majority of clients from both public and private facilities expressed satisfaction with quality of services from admission till discharge in both public and private facilities and were willing to recommend other to come and deliver in the respective facilities
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