922017 research outputs found
Sort by
A five-spin supramolecule for simulating quantum decoherence of Bell states
No full textWe report a supramolecule that contains five spins of two different types, and with, crucially, two different and predictable interaction energies between the spins. The supramolecule is characterised and the interaction energies demonstrated by EPR spectroscopy. Based on the measured parameters we propose experiments that would allow this designed supramolecule to be used to simulate quantum decoherence in maximally entangled Bell states that could be used in quantum teleportation
Scaleability of dielectric susceptibility ϵzz with the number of layers and additivity of ferroelectric polarization in van der Waals semiconductors
No full textWe study the dielectric response of few layered crystals of various transition metal dichalcogenides (TMDs) and hexagonal Boron Nitride (hBN). We showed that the out-of-plane polarizability of a multilayer crystal (which characterizes response to the external displacement field) scales linearly with the number of layers, αNL zz = Nα1L zz , independently of the stacking configuration in the film. We also established additivity of ferroelectric polarizations of consecutive interfaces in case when such interfaces have broken inversion symmetry. Then we used the obtained data of monolayer α1L zz to calculate the values of the dielectric susceptibilities for semiconductor TMDs and hBN bulk crystals
PHANGS-JWST First Results: Spurring on Star Formation:JWST Reveals Localised Star Formation in a Spiral Arm Spur of NGC 628
No full textWe combine JWST observations with ALMA CO and VLT-MUSE Hα data to examine off-spiral arm star formation in the face-on, grand-design spiral galaxy NGC 628. We focus on the northern spiral arm, around a galactocentric radius of 3-4 kpc, and study two spurs. These form an interesting contrast, as one is CO-rich and one CO-poor, and they have a maximum azimuthal offset in MIRI 21μm and MUSE Hα of around 40∘ (CO-rich) and 55∘ (CO-poor) from the spiral arm. The star formation rate is higher in the regions of the spurs near to spiral arms, but the star formation efficiency appears relatively constant. Given the spiral pattern speed and rotation curve of this galaxy and assuming material exiting the arms undergoes purely circular motion, these offsets would be reached in 100-150 Myr, significantly longer than the 21μm and Hα star formation timescales (bot
Genetically proxied TYK2 inhibition is associated with reduced sarcoidosis susceptibility
No full textPicturing Displaced Persons (DPs), Exhibiting French Prestige? Photographs of humanitarian aid for European DPs in French-occupied Germany, c. 1945-1952
No full textThis article explores how photography documenting humanitarian aid for European DPs in French-occupied Germany was mobilised to enhance France’s image in Allied occupied Germany, against the backdrop of increasing anxieties about its international standing. It draws on a selection of images found in the archives of the United Nations Relief and Rehabilitation Administration [UNRRA] and the French occupation zone at La Courneuve, which sat between the ‘official’ and the ‘private’. In doing so, this article calls for a recognition of the role of amateur and relief workers photographers in sustaining post-war visual discourses of internationalism and national-self fashioning. Although largely overlooked today, these images play a role in wider debates about what it meant to be ‘French’ in the aftermath of the Nazi occupation. In particular, relief workers and amateur photographers built on and reproduced aspects of the widely disseminated narrative about the universalism of resistance that was being circulated in metropolitan France and Britain at the same time to disrupt conventional images of the French zone as a refuge for French wartime collaborators. Ultimately, this article argues that this hitherto neglected aspect of humanitarian imagery offers fresh insights into the contribution of relief workers and amateur photographers to French post-war diplomatic and occupation strategies
Elucidating Heterogeneous Iron Biomineralization Patterns in a Denitrifying As(III)-Oxidizing Bacterium: Implications for Arsenic Immobilization
No full textAnaerobic nitrate-dependent iron(II) oxidation is a process common to many bacterial species, which promotes the formation of Fe(III) minerals that can influence the fate of soil and groundwater pollutants, such as arsenic. Herein, we investigated simultaneous nitrate-dependent Fe(II) and As(III) oxidation by Acidovorax sp. strain ST3 with the aim of studying the Fe biominerals formed, their As immobilization capabilities and the metabolic effect on cells. X-ray powder diffraction (XRD) and scanning transmission electron microscopy (STEM) nanodiffraction were applied for biomineral characterization in bulk and at the nanoscale, respectively. NanoSIMS (nanoscale secondary ion mass spectrometry) was used to map the intra and extracellular As and Fe distribution at the single-cell level and to trace metabolically active cells, by incorporation of a 13C-labeled substrate (acetate). Metabolic heterogeneity among bacterial cells was detected, with periplasmic Fe mineral encrustation deleterious to cell metabolism. Interestingly, Fe and As were not co-localized in all cells, indicating delocalized sites of As(III) and Fe(II) oxidation. The Fe(III) minerals lepidocrocite and goethite were identified in XRD, although only lepidocrocite was identified via STEM nanodiffraction. Extracellular amorphous nanoparticles were formed earlier and retained more As(III/V) than crystalline “flakes” of lepidocrocite, indicating that longer incubation periods promote the formation of more crystalline minerals with lower As retention capabilities. Thus, the addition of nitrate promotes Fe(II) oxidation and formation of Fe(III) biominerals by ST3 cells which retain As(III/V), and although this process was metabolically detrimental to some cells, it warrants further examination as a viable mechanism for As removal in anoxic environments by biostimulation with nitrate
Wit4Java: A Violation-Witness Validator for Java Verifiers
No full textWe describe and evaluate a violation-witness validator for Java verifiers called Wit4Java. It takes a Java program with a safety property and the respective violation-witness output by a Java verifier to generate a new Java program whose execution deterministically violates the property. We extract the value of the program variables from the counterexample represented by the violation witness and feed this information back into the original program. In addition, we have two implementations for instantiating source programs by injecting counterexamples. Experimental results show that Wit4Java can correctly validate the violation-witnesses produced by JBMC and GDart in a few seconds
Simultaneous Distillation-Extraction for Manufacturing Ultra-High-Purity Electronic-Grade Octamethylcyclotetrasiloxane (D4)
No full textUltra-high-purity (UHP) electronic-grade octamethylcyclotetrasiloxane (D4) is the key precursor of low-dielectric constant (low-k) SiCOH films to manufacture integrated circuits (IC), meeting the stringent requirements of the rapidly developing semiconductor industry. Commonly, metallic impurities in D4 were removed by multiple unit operations of adsorption, filtration, and distillation, which could reduce the concentration of a single metallic impurity below 1 ppb. However, D4 with higher purity is required by semiconductor production due to an increase in transistor density. Herein, a novel method based on the integrated simultaneous distillation-extraction (SDE) was developed for manufacturing UHP electronic-grade D4. The lab and pilot scale experiments showed that the purity of water and D4 has a positive correlation. Based on the experimental data, a double-column process, consisting of azeotropic/extractive distillation column and precision distillation column with UNIQUAC method, was established to access the feasibility of scaling up the SDE process. According to the simulation results, D4 with the purity >99.999 wt.% and total metallic impurities (TMI) content below 1 ppb could be obtained using ultra-pure water. Keywords: Octamethylcyclotetrasiloxane (D4), Process integration, Simultaneous distillation-extraction, Electronic-Grade<br/
Review of 'Harnessing Public Research for Innovation in the 21st Century: An International Assessment of Knowledge Transfer Policies. Edited by: Anthony Arundel, Suma Athreye and Sacha Wunsch-Vincent Cambridge and the World Intellectual Property Organization. Cambridge, United Kingdom. 2021. 502 pp. ISBN 9781108842792'
No full textCombining Topic Modeling with Grounded Theory: Case Studies of Project Collaboration
No full textThis paper proposes an Artificial Intelligence (AI) Grounded Theory for management studies. We argue that this novel and rigorous approach that embeds topic modelling will lead to the latent knowledge to be found. We illustrate this abductive method using 51 case studies of collaborative innovation published by Project Management Institute (PMI). Initial results are presented and discussed that include 40 topics, 6 categories, 4 of which are core categories, and two new theories of project collaboration