Advanced hybrid joints, which incorporate a specially designed array of macro-scale pins that provide mechanical interlocking reinforcement, have been developed in order to address the challenges ...associated with joining fibre reinforced composites to metals. In the present work, important joint characteristics including strength, mechanical fatigue, damage tolerance and durability have been studied and discussed. The results indicate that with advanced hybrid joints it is possible to achieve the benefits of the respective bonded and bolted systems but with virtually zero net weight gain, or conceivably a weight reduction as the increased performance of the hybrid scheme could facilitate smaller joints. The authors also present initial results from a comprehensive manufacturing and scalability trial, and demonstrate that low-cost, large-scale manufacture of hybrid joints is now feasible.
Despite many decades of study the physical origin of 'dark matter' (DM) in the Universe remains elusive. In this letter we calculate the properties of a completely new DM candidate-Bose-Einstein ...condensates formed from a recently discovered bosonic particle in the light-quark sector, the d * ( 2380 ) hexaquark. In this first study, we show stable d ∗ ( 2380 ) Bose-Einstein condensates could form in the primordial early universe, with a production rate sufficiently large that they are a plausible new candidate for DM. Some possible astronomical signatures of such DM are also presented.
Positron Emission Tomography (PET) is a widely-used imaging modality for medical research and clinical diagnosis. Imaging of the radiotracer is obtained from the detected hit positions of the two ...positron annihilation photons in a detector array. The image is degraded by backgrounds from random coincidences and in-patient scatter events which require correction. In addition to the geometric information, the two annihilation photons are predicted to be produced in a quantum-entangled state, resulting in enhanced correlations between their subsequent interaction processes. To explore this, the predicted entanglement in linear polarisation for the two photons was incorporated into a simulation and tested by comparison with experimental data from a cadmium zinc telluride (CZT) PET demonstrator apparatus. Adapted apparati also enabled correlation measurements where one of the photons had undergone a prior scatter process. We show that the entangled simulation describes the measured correlations and, through simulation of a larger preclinical PET scanner, illustrate a simple method to quantify and remove the unwanted backgrounds in PET using the quantum entanglement information alone.
•Sources and particle sizes of biochars influenced biochar mineralization and stability.•Stability of biochar in soil is salient feature to evaluate its use as C sequestration tool.•Biochar processed ...into pellets and dust-sized had significant effect on its mineralization.•Site specific application is an effective use of biochar as a soil amendment.
Biochar produced during pyrolysis has the potential to enhance soil fertility and reduce greenhouse gas emissions. The influence of biochar properties (e.g., particle size) on both short- and long-term carbon (C) mineralization of biochar remains unclear. There is minimal information on the potential effects of biochar particle sizes on their breakdowns by soil microorganism, so it is unknown if the particle size of biochar influences C mineralization rate and/or stability in soils. In order to evaluate the effect of different sources (BS) and particle sizes (BF) of biochar on C loss and/or stability in soils, an incubation study on C mineralization of different biochar sources and particle sizes was established using two soils (ST): Norfolk soil (fine loamy, kaolinitic, thermic, typic Kandiudults) and Coxville soil (fine loamy kaolinitic, thermic, Paleaquults). In separate incubation vessels, these soils were amended with one of two manure-based biochars (poultry litters, PL; swine solids, SS) or one of two lignocellulosic-based biochars (switchgrass, SG; pine chips, PC) which were processed into two particle sizes (dust, <0.42mm; pellet, >2mm). The amount of CO2 evolved varied significantly between soils (p⩽0.0001); particle sizes (p⩽0.0001) and the interactions of biochar source (p⩽0.001) and forms of biochars (p⩽0.0001) with soil types. Averaged across soils and sources of biochar, CO2-C evolved from dust-sized biochar (281mgkg−1) was significantly higher than pellet-sized biochar (226mgkg−1). Coxville soils with SS biochar produced the greatest average CO2-C of 428mgkg−1 and Norfolk soils with PC had the lowest CO2-C production (93mgkg−1). Measured rates of carbon mineralization also varied with soils and sources of biochar (Norfolk: PL>SS>SG⩾PC; Coxville: PC>SG>SS>PL). The average net CO2-C evolved from the Coxville soils (385mgkg−1) was about threefold more than the CO2-C evolved from the Norfolk soils (123mgkg−1). Our results suggest different particle sizes and sources of biochar as well as soil type influence biochar stability.
Abstract
We study how environment regulates the star formation cycle of 33 Virgo Cluster satellite galaxies on 720 pc scales. We present the resolved star-forming main sequence for cluster galaxies, ...dividing the sample based on their global H
i
properties and comparing to a control sample of field galaxies. H
i
–poor cluster galaxies have reduced star formation rate (SFR) surface densities with respect to both H
i
–normal cluster and field galaxies (∼0.5 dex), suggesting that mechanisms regulating the global H
i
content are responsible for quenching local star formation. We demonstrate that the observed quenching in H
i
–poor galaxies is caused by environmental processes such as ram pressure stripping (RPS), simultaneously reducing the molecular gas surface density and star formation efficiency (SFE) compared to regions in H
i
–normal systems (by 0.38 and 0.22 dex, respectively). We observe systematically elevated SFRs that are driven by increased molecular gas surface densities at fixed stellar mass surface density in the outskirts of early stage RPS galaxies, while SFE remains unchanged with respect to the field sample. We quantify how RPS and starvation affect the star formation cycle of inner and outer galaxy disks as they are processed by the cluster. We show both are effective quenching mechanisms, with the key difference being that RPS acts upon the galaxy outskirts while starvation regulates the star formation cycle throughout disk, including within the truncation radius. For both processes, the quenching is caused by a simultaneous reduction in the molecular gas surface densities and SFE at fixed stellar mass surface density.
Accurate radiographic diagnosis of vertebral fractures is important. This multicenter, multinational study assessed radiographic diagnoses of vertebral fracture in 2451 postmenopausal women with ...osteoporosis. Comparison between local and central readings yielded a false‐negative rate of 34%. Underdiagnosis of vertebral fracture is a worldwide problem.
Introduction: Vertebral fractures are the most common complication of osteoporosis. Although they are associated with significant morbidity, they frequently do not come to clinical attention. Accurate radiographic diagnosis is important.
Materials and Methods: In a multicenter, multinational prospective study (the IMPACT trial), the accuracy of radiographic diagnosis of vertebral fracture was evaluated in postmenopausal women 65–80 years of age newly diagnosed with osteoporosis (based on BMD measurement). Lateral radiographs of the thoracolumbar spine were evaluated for identification of vertebral fractures, first locally and subsequently at a central reading center, using a validated semiquantitative method. False‐positive and false‐negative rates were calculated based on adjudicated discrepancies between the initial interpretation at the local site and the subsequent central reading, considered the “reference standard.”
Results: Of 2451 women with an evaluable radiograph both centrally and locally, 789 (32%) had at least one vertebral fracture. Adjudicated discrepancies (n = 350 patients) between local and central readings because of undetected vertebral fracture (68%) or equivocal terminology in the local radiology report (32%) yielded a false‐negative rate of 34%.
Conclusions: Underdiagnosis of vertebral fractures was observed in all geographic regions (false‐negative rates: North America, 45.2%; Latin America, 46.5%; Europe/South Africa/Australia, 29.5%). The false‐positive rate was 5% globally. Underdiagnosis of vertebral fracture is a worldwide problem attributable in part to a lack of radiographic detection, use of ambiguous terminology in the radiology report, or both. Efforts to improve accuracy and reduce variability in terminology and interpretation may increase the effectiveness of spinal radiography for detecting vertebral fractures in patients with osteoporosis.
The assimilation of AIRS radiance data at ECMWF Mcnally, A. P.; Watts, P. D.; A. Smith, J. ...
Quarterly journal of the Royal Meteorological Society,
April 2006 Part A, Letnik:
132, Številka:
616
Journal Article
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