102 research outputs found
Deformation Rate and Temperature Sensitivity in TWIP/TRIP VCrFeCoNi Multi-Principal Element Alloy
High-entropy alloys (HEAs) and medium-entropy alloys (MEAs), also sometimes referred to as multi-principal element alloys (MPEAs), present opportunities to develop new materials with outstanding mechanical properties. Through the careful selection of constituent elements along with optimized thermal processing for proper control of structure, grain size, and deformation mechanisms, many of the newly developed HEA systems exhibit superior strength and ductility levels across a wide range of temperatures, particularly at cryogenic deformation temperatures. Such a remarkable response has been attributed to the hardening capacity of many MPEAs that is achieved through the activation of deformation twinning. More recent compositions have considered phase transforming systems, which have the potential for enhanced strengthening and therefore high strength and ductility levels. However, the strain rate sensitivity of such transforming MPEAs is not well understood and requires further investigation. In this study, the tensile properties of the non-equiatomic V10Cr10Fe45Co30Ni5 MPEA were investigated at different deformation rates and temperatures ranging from 77 K (-196 degrees C) to 573 K (300 degrees C). Depending on the deformation temperature, the considered MPEA exhibits plasticity through either crystallographic slip, deformation twinning, or solid-state phase transformation. At 300 degrees C, only slip-mediated plasticity was observed for all the considered deformation rates. Deformation twinning was detected in samples deformed at room temperature, while face-centered cubic to body-centered cubic phase transformation became more favorable at cryogenic deformation temperatures. The trends are nonlinear with twinning-induced plasticity (TWIP) favored at the intermediate deformation rate, while transformation-induced plasticity (TRIP) was observed, although limited, only at the slowest deformation rate. For all the considered deformation rates at cryogenic deformation temperature, a significant TRIP activity was always detected. The extent of TRIP, however, was dependent on the deformation rate. Increasing the deformation rate is not conducive to TRIP and thus hinders the hardening capacity
FIBS: A Generic Framework for Classifying Interval-based Temporal Sequences
We study the problem of classifying interval-based temporal sequences
(IBTSs). Since common classification algorithms cannot be directly applied to
IBTSs, the main challenge is to define a set of features that effectively
represents the data such that classifiers can be applied. Most prior work
utilizes frequent pattern mining to define a feature set based on discovered
patterns. However, frequent pattern mining is computationally expensive and
often discovers many irrelevant patterns. To address this shortcoming, we
propose the FIBS framework for classifying IBTSs. FIBS extracts features
relevant to classification from IBTSs based on relative frequency and temporal
relations. To avoid selecting irrelevant features, a filter-based selection
strategy is incorporated into FIBS. Our empirical evaluation on eight
real-world datasets demonstrates the effectiveness of our methods in practice.
The results provide evidence that FIBS effectively represents IBTSs for
classification algorithms, which contributes to similar or significantly better
accuracy compared to state-of-the-art competitors. It also suggests that the
feature selection strategy is beneficial to FIBS's performance.Comment: In: Big Data Analytics and Knowledge Discovery. DaWaK 2020. Springer,
Cha
Coherent and squeezed states of quantum Heisenberg algebras
Starting from deformed quantum Heisenberg Lie algebras some realizations are
given in terms of the usual creation and annihilation operators of the standard
harmonic oscillator. Then the associated algebra eigenstates are computed and
give rise to new classes of deformed coherent and squeezed states. They are
parametrized by deformed algebra parameters and suitable redefinitions of them
as paragrassmann numbers. Some properties of these deformed states also are
analyzed.Comment: 32 pages, 3 figure
Banff 2022 liver group meeting report: monitoring long term allograft health.
The Banff Working Group on Liver Allograft Pathology met in September 2022. Participantsincluded hepatologists, surgeons, pathologists, immunologists and histocompatibility specialists.Presentations and discussions focused on the evaluation of long-term allograft health, including noninvasive and tissue monitoring, immunosuppression optimisation and long-term structural changes.Potential revision of the rejection classification scheme to better accommodate and communicate lateT cell-mediated rejection patterns and related structural changes, such as nodular regenerativehyperplasia, were discussed. Improved stratification of long-term maintenance immunosuppression tomatch the heterogeneity of patient settings will be central to improving long-term patient survival.Such personalised therapeutics are in turn contingent on better understanding and monitoring ofallograft status within a rational decision-making approach, likely to be facilitated in implementationwith emerging decision support tools. Proposed revisions to rejection classification emerging fromthe meeting include incorporation of interface hepatitis and fibrosis staging. These will be opened toonline testing, modified accordingly and subject to consensus discussion leading up to the next Banffconference
Strong protective effect of the APOL1 p.N264K variant against G2-associated focal segmental glomerulosclerosis and kidney disease
African Americans have a significantly higher risk of developing chronic kidney disease, especially focal segmental glomerulosclerosis -, than European Americans. Two coding variants (G1 and G2) in the APOL1 gene play a major role in this disparity. While 13% of African Americans carry the high-risk recessive genotypes, only a fraction of these individuals develops FSGS or kidney failure, indicating the involvement of additional disease modifiers. Here, we show that the presence of the APOL1 p.N264K missense variant, when co-inherited with the G2 APOL1 risk allele, substantially reduces the penetrance of the G1G2 and G2G2 high-risk genotypes by rendering these genotypes low-risk. These results align with prior functional evidence showing that the p.N264K variant reduces the toxicity of the APOL1 high-risk alleles. These findings have important implications for our understanding of the mechanisms of APOL1-associated nephropathy, as well as for the clinical management of individuals with high-risk genotypes that include the G2 allele
Operating a full tungsten actively cooled tokamak: overview of WEST first phase of operation
WEST is an MA class superconducting, actively cooled, full tungsten (W) tokamak, designed to operate in long pulses up to 1000 s. In support of ITER operation and DEMO conceptual activities, key missions of WEST are: (i) qualification of high heat flux plasma-facing components in integrating both technological and physics aspects in relevant heat and particle exhaust conditions, particularly for the tungsten monoblocks foreseen in ITER divertor; (ii) integrated steady-state operation at high confinement, with a focus on power exhaust issues. During the phase 1 of operation (2017–2020), a set of actively cooled ITER-grade plasma facing unit prototypes was integrated into the inertially cooled W coated startup lower divertor. Up to 8.8 MW of RF power has been coupled to the plasma and divertor heat flux of up to 6 MW m−2 were reached. Long pulse operation was started, using the upper actively cooled divertor, with a discharge of about 1 min achieved. This paper gives an overview of the results achieved in phase 1. Perspectives for phase 2, operating with the full capability of the device with the complete ITER-grade actively cooled lower divertor, are also described
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Background: Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. // Methods: We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung's disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. // Findings: We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung's disease) from 264 hospitals (89 in high-income countries, 166 in middle-income countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in low-income countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. // Interpretation: Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between low-income, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030
Reducing Bacterial Contamination in Fuel Ethanol Fermentations by Ozone Treatment of Uncooked Corn Mash
Ozonation of uncooked corn mash from the POET BPX process was investigated as a potential disinfection method for reducing bacterial contamination prior to ethanol fermentation. Corn mash (200 g) was prepared from POET ground corn and POET corn slurry and was ozonated in 250 mL polypropylene bottles. Lactic and acetic acid levels were monitored daily during the fermentation of ozonated, aerated, and nontreated corn mash samples to evaluate bacterial activity. Glycerol and ethanol contents of fermentation samples were checked daily to assess yeast activity. No yeast supplementation, no addition of other antimicrobial agents (such as antibiotics), and spiking with a common lactic acid bacterium found in corn ethanol plants,Lactobacillus plantarum, amplified the treatment effects. The laboratory-scale ozone dosages ranged from 26–188 mg/L, with very low estimated costs of 0.21–1.6/m3) of ethanol. Ozonation was found to decrease the initial pH of ground corn mash samples, which could reduce the sulfuric acid required to adjust the pH prior to ethanol fermentation. Lactic and acetic acid levels tended to be lower for samples subjected to increasing ozone dosages, indicating less bacterial activity. The lower ozone dosages in the range applied achieved higher ethanol yields. Preliminary experiments on ozonating POET corn slurry at low ozone dosages were not as effective as using POET ground corn, possibly because corn slurry samples contained recycled antimicrobials from the backset. The data suggest additional dissolved and suspended organic materials from the backset consumed the ozone or shielded the bacteria.Reprinted with permission from J. Agric. Food Chem., 2015, 63 (21), pp 5239–5248. doi: 10.1021/acs.jafc.5b00563. Copyright 2015 American Chemical Society.</p
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