Abstract
Despite a plethora of data being generated on the mechanical behavior of multi-principal element alloys, a systematic assessment remains inaccessible via Edisonian approaches. We approach ...this challenge by considering the specific case of alloy hardness, and present a machine-learning framework that captures the essential physical features contributing to hardness and allows high-throughput exploration of multi-dimensional compositional space. The model, tested on diverse datasets, was used to explore and successfully predict hardness in Al
x
Ti
y
(CrFeNi)
1-
x
-
y
, Hf
x
Co
y
(CrFeNi)
1-
x
-
y
and Al
x
(TiZrHf)
1-
x
systems supported by data from density-functional theory predicted phase stability and ordering behavior. The experimental validation of hardness was done on TiZrHfAl
x
. The selected systems pose diverse challenges due to the presence of ordering and clustering pairs, as well as vacancy-stabilized novel structures. We also present a detailed model analysis that integrates local partial-dependencies with a compositional-stimulus and model-response study to derive material-specific insights from the decision-making process.
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Efficient alloy design requires a knowledge of phase selection, phase-fractions and microstructure of the material. Prediction of the phase equilibria, though well-established for ...traditional alloys, is still an open challenge for novel materials and concentrated multicomponent systems such as the High-Entropy Alloys (HEAs). In this paper, we present a novel data-driven approach for learning the phase-equilibria in HEAs through the use of a stochastic ensemble averaging method. The proposed model employs a model-averaging technique on an ensemble of 150 artificial neural networks that have been trained on a 323 alloy dataset. A seven-label classification is presented using a three-element vector description of phases. This allows us to fit the classification boundaries to a relatively larger number of phase combination labels while using only three target parameters for training thereby improving accuracy. The phase prediction capabilities (i.e., formation of FCC, BCC, intermetallics or different combinations of these phases) were tested on 320 alloys outside of the training dataset. Additionally, quantitative estimate of the phase equilibria, i.e., relative phase-fractions, were estimated and compared with experimental measurements and CALPHAD predictions in three different high-entropy systems, viz., Fex-Niy-(AlCoCr0.5)1-x-y, Alx-Tiy-(CrFeNi)1-x-y and Crx-Moy-(VNbTi)1-x-y. The model’s capability of going a step beyond current state-of-the-art model allows greater insights into target composition spaces for the alloy designer and establishes the first such approach for HEAs.
The LIGO Scientific Collaboration and the Virgo Collaboration have cataloged eleven confidently detected gravitational-wave events during the first two observing runs of the advanced detector era. ...All eleven events were consistent with being from well-modeled mergers between compact stellar-mass objects: black holes or neutron stars. The data around the time of each of these events have been made publicly available through the gravitational-wave open science center. The entirety of the gravitational-wave strain data from the first and second observing runs have also now been made publicly available. There is considerable interest among the broad scientific community in understanding the data and methods used in the analyses. In this paper, we provide an overview of the detector noise properties and the data analysis techniques used to detect gravitational-wave signals and infer the source properties. We describe some of the checks that are performed to validate the analyses and results from the observations of gravitational-wave events. We also address concerns that have been raised about various properties of LIGO-Virgo detector noise and the correctness of our analyses as applied to the resulting data.
GW170817 is the very first observation of gravitational waves originating from the coalescence of two compact objects in the mass range of neutron stars, accompanied by electromagnetic counterparts, ...and offers an opportunity to directly probe the internal structure of neutron stars. We perform Bayesian model selection on a wide range of theoretical predictions for the neutron star equation of state. For the binary neutron star hypothesis, we find that we cannot rule out the majority of theoretical models considered. In addition, the gravitational-wave data alone does not rule out the possibility that one or both objects were low-mass black holes. We discuss the possible outcomes in the case of a binary neutron star merger, finding that all scenarios from prompt collapse to long-lived or even stable remnants are possible. For long-lived remnants, we place an upper limit of 1.9 kHz on the rotation rate. If a black hole was formed any time after merger and the coalescing stars were slowly rotating, then the maximum baryonic mass of non-rotating neutron stars is at most , and three equations of state considered here can be ruled out. We obtain a tighter limit of for the case that the merger results in a hypermassive neutron star.
Purpose: Coronavirus disease (COVID-19) remains a health concern with new emerging challenges as rise of opportunistic mucormycosis infections in COVID-19 patients has been found to increase ...morbidity and mortality. Even though rare, COVID-19 associated mucormycosis has been reported from across the world. We present a retrospective cases series of 132 patients diagnosed as COVID-19 associated mucormycosis in a tertiary care hospital in North India during May 9th to 30th 2021. Materials and Methods: Our 1500 bed tertiary care hospital is one of the partners in the Mycotic Infections in COVID-19 (MUNCO) registry, Albert Einstein College of Medicine, Bronx, New York. Data were collected in the REDCap database. Profile of the patients has been presented according to demographic profile, comorbidities, laboratory parameters, ICU admission, oxygen support and treatment outcomes. Analysis of risk factors for mortality has been undertaken along with a prediction model for mortality. Result: The proportion of males and females was 72.7% and 27.3% respectively. The mean age of the study subjects was 53.1 years. The major comorbidity was Diabetes (57.6%) followed by Hypertension (40.9%) and Coronary artery disease (11.4%). About 13% patients used long term corticosteroid. Further, 70.5% patients required an ICU admission and 47.0% patients required oxygen support whereas ventilator requirement was for 13.6% patients. Overall death rate of mucormycosis patients was 16.7%. The risk factors identified for death were raised levels of CRP >73, Ferritin >358, SGOT >39 and Creatinine >1.15 as well as oxygen requirement. Conclusion: Clinicians must examine the possibility of concomitant fungal infection in COVID-19 patients especially who are geriatric or comorbid with Diabetes Mellitus. Those with raised levels of CRP, Ferritin, SGOT and Creatinine levels as well as those needing oxygen need to be vigilantly monitored to minimize the risk of mortality.
The gravitational-wave signal GW190521 is consistent with a binary black hole (BBH) merger source at redshift 0.8 with unusually high component masses, M ⊙ and M ⊙, compared to previously reported ...events, and shows mild evidence for spin-induced orbital precession. The primary falls in the mass gap predicted by (pulsational) pair-instability supernova theory, in the approximate range 65–120 M ⊙. The probability that at least one of the black holes in GW190521 is in that range is 99.0%. The final mass of the merger ( M ⊙) classifies it as an intermediate-mass black hole. Under the assumption of a quasi-circular BBH coalescence, we detail the physical properties of GW190521’s source binary and its post-merger remnant, including component masses and spin vectors. Three different waveform models, as well as direct comparison to numerical solutions of general relativity, yield consistent estimates of these properties. Tests of strong-field general relativity targeting the merger-ringdown stages of the coalescence indicate consistency of the observed signal with theoretical predictions. We estimate the merger rate of similar systems to be . We discuss the astrophysical implications of GW190521 for stellar collapse and for the possible formation of black holes in the pair-instability mass gap through various channels: via (multiple) stellar coalescences, or via hierarchical mergers of lower-mass black holes in star clusters or in active galactic nuclei. We find it to be unlikely that GW190521 is a strongly lensed signal of a lower-mass black hole binary merger. We also discuss more exotic possible sources for GW190521, including a highly eccentric black hole binary, or a primordial black hole binary.
Abstract Objective The objective of this study was to evaluate left ventricular free wall and interventricular septal function by 2-dimensional transthoracic echocardiography and live/real-time ...3-dimensional transthoracic speckle tracking echocardiography before and after on-pump cardiac surgery and to assess the effect of mode of cardioplegia delivery. Methods A total of 22 patients were studied 1 day before and 4 to 5 days after surgery. Cold blood cardioplegia was delivered by intermittent antegrade infusion or by the integrated method. The latter includes a combination of intermittent antegrade and retrograde cardioplegia with a terminal warm amino acid–enriched reperfusion. Results The overall group displayed significant deterioration of septal function after surgery by 2-dimensional transthoracic echocardiography, as assessed by wall motion score index, yet subgroup analysis by 3-dimensional transthoracic speckle tracking echocardiography permitted distinction of outcomes achieved by antegrade or integrated delivery methods. Analysis after surgery showed that only the antegrade group displayed statistically significant deterioration in the strain parameters of some of the segments of the septum and free wall when strain was measured in the free wall and septum in the longitudinal, circumferential, and radial modes of deformation ( P < .05). In contrast, only the integrated group displayed significant improvement in global radial, circumferential, and longitudinal strain ( P < .05). Conclusions These findings by 3-dimensional transthoracic speckle tracking echocardiography indicate that integrated cardioplegia offers superior myocardial protection of the left ventricular free wall and septum compared with the antegrade mode of cardioplegia delivery.
We search for signatures of gravitational lensing in the gravitational-wave signals from compact binary coalescences detected by Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) ...and Advanced Virgo during O3a, the first half of their third observing run. We study: (1) the expected rate of lensing at current detector sensitivity and the implications of a non-observation of strong lensing or a stochastic gravitational-wave background on the merger-rate density at high redshift; (2) how the interpretation of individual high-mass events would change if they were found to be lensed; (3) the possibility of multiple images due to strong lensing by galaxies or galaxy clusters; and (4) possible wave-optics effects due to point-mass microlenses. Several pairs of signals in the multiple-image analysis show similar parameters and, in this sense, are nominally consistent with the strong lensing hypothesis. However, taking into account population priors, selection effects, and the prior odds against lensing, these events do not provide sufficient evidence for lensing. Overall, we find no compelling evidence for lensing in the observed gravitational-wave signals from any of these analyses.
A
bstract
We analyse a simple extension of the SM with just an additional scalar singlet coupled to the Higgs boson. We discuss the possible probes for electroweak baryogenesis in this model ...including collider searches, gravitational wave and direct dark matter detection signals. We show that a large portion of the model parameter space exists where the observation of gravitational waves would allow detection while the indirect collider searches would not.
Curcumin, a derived product from common spice turmeric that is safe and beneficial in several aliments was formulated into biodegradable nanoparticles with a view to improve its oral bioavailability. ...The curcumin encapsulated nanoparticles prepared by emulsion technique were spherical in shape with particle size of 264
nm (polydispersity index 0.31) and 76.9% entrapment at 15% loading. The curcumin encapsulated nanoparticles were able to withstand the International Conference on Harmonisation (ICH) accelerated stability test conditions for refrigerated products for the studied duration of 3 months. X-ray diffraction analysis revealed the amorphous nature of the encapsulated curcumin. The
in vitro release was predominantly by diffusion phenomenon and followed Higuchi's release pattern. The
in vivo pharmacokinetics revealed that curcumin entrapped nanoparticles demonstrate at least 9-fold increase in oral bioavailability when compared to curcumin administered with piperine as absorption enhancer. Together the results clearly indicate the promise of nanoparticles for oral delivery of poorly bioavailable molecules like curcumin.
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