Viscous coalescence of droplets: a Lattice Boltzmann study

The coalescence of two resting liquid droplets in a saturated vapor phase is investigated by Lattice Boltzmann simulations in two and three dimensions. We find that, in the viscous regime, the bridge radius obeys a t^{1/2}-scaling law in time with the characteristic time scale given by the viscous time. Our results differ significantly from the predictions of existing analytical theories of viscous coalescence as well as from experimental observations. While the underlying reason for these deviations is presently unknown, a simple scaling argument is given that describes our results well.Comment: 12 pages, 10 figures; as published in Phys. Fluid

A Machine Learning Approach for Gearbox System Fault Diagnosis

This study proposes a fully automated gearbox fault diagnosis approach that does not require knowledge about the specific gearbox construction and its load. The proposed approach is based on evaluating an adaptive filter's prediction error. The obtained prediction error's standard deviation is further processed with a support-vector machine to classify the gearbox's condition. The proposed method was cross-validated on a public dataset, segmented into 1760 test samples, against two other reference methods. The accuracy achieved by the proposed method was better than the accuracies of the reference methods. The accuracy of the proposed method was on average 9% higher compared to both reference methods for different support vector settings

Thermal Kinetic Inductance Detectors for Millimeter-Wave Astrophysics

Thermal Kinetic Inductance Detectors (TKIDs) combine the excellent noise performance of traditional bolometers with a radio frequency (RF) multiplexing architecture that enables the large detector counts needed for the next generation of millimeter-wave instruments. Here we present dark prototype TKID pixels that demonstrate a noise equivalent power NEP = 2×10⁻¹⁷√W/Hz with a 1/f knee at 0.1 Hz, suitable for background-limited noise performance at 150 GHz from a ground-based site. We discuss the optimizations in the device design and fabrication techniques to realize optimal electrical performance and high quality factors at a bath temperature of 250 mK

Roughness gradient induced spontaneous motion of droplets on hydrophobic surfaces: A lattice Boltzmann study

The effect of a step wise change in the pillar density on the dynamics of droplets is investigated via three-dimensional lattice Boltzmann simulations. For the same pillar density gradient but different pillar arrangements, both motion over the gradient zone as well as complete arrest are observed. In the moving case, the droplet velocity scales approximately linearly with the texture gradient. A simple model is provided reproducing the observed linear behavior. The model also predicts a linear dependence of droplet velocity on surface tension. This prediction is clearly confirmed via our computer simulations for a wide range of surface tensions.Comment: 6 pages, 8 figure

Stochastic simulations of the quantum Zeno effect

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ESG Trends: Results of the 2022 HR@Moore Survey of CHROs

There has been incredible momentum in recent years for the expectation that major companies should be attentive to and deliver results on Environmental, Social, and Governance (ESG) issues. For their part, companies and their executive leadership teams (ELTs) seem responsive to these expectations, developing ESG strategies and devoting resources to making progress in these areas. Perhaps the most notable commitment along these lines came in 2019, when the Business Roundtable (BRT) issued a statement to “redefine the purpose of a corporation” to focus on all stakeholders rather than be predominantly centered on shareholders. Much of the conversation around corporations in the years since, through the pandemic, George Floyd’s murder, growing climate concerns, and more, has only accelerated the focus on ESG. Given these developments, we asked CHROs a series of ESG-related questions intended to gather insight into how their ELTs’ time and attention devoted to stakeholder issues is changing and on what activities they are spending that time. The majority of CHROs report an increase in their ELT’s time devoted to non-shareholder stakeholders in recent years, exemplifying the principles of the BRT statement. In other words, the CHROs we heard from broadly feel, on average, as though the BRT statement is a reality in their ELTs and at their companies. Our respondents also report a substantial variety of initiatives their ELTs are currently engaged in for each of the environmental, social, and governance domains. Perhaps unsurprisingly, emissions reduction and diversity, equity, and inclusion (DEI) dominated the responses in the environmental and social categories, respectively, with over 80% of CHROs citing their company’s efforts in these areas. But underneath those headliners was an assortment of initiatives on a wide range of ESG issues that ELTs are committed to making a positive impact. An interesting pattern of relationships emerged between these initiatives and the CHROs’ ratings of their company’s environmental, social, and employee-focused performance relative to their closest competitors. The category of environmental initiatives that was most strongly related to environmental performance was those seeking to address grand societal challenges, whereas those focused on internal capabilities and waste reduction were actually negatively related. These relationships suggest that CHROs of companies thinking (and acting) more broadly in their environmental initiatives are more optimistic about their company’s environmental impact. 4 HR@MOORE | sc.edu/moore/ces The relationships in the social domain were even more striking. Employee focused initiatives (e.g., DEI, employee engagement, safety) were only weakly related to CHRO ratings of the company’s performance in “attracting and retaining key employees” but were all negatively related to the ratings of social performance. In contrast, externally focused initiatives (e.g., community engagement, racial justice, community workforce development) were far more strongly related to CHRO ratings of company social performance and the company’s ability to attract and retain employees. These findings suggest there may be more “win-wins” created through social initiatives that seek to make an impact outside the company compared to those that are strictly focused on supporting employees. For this report, and as part of the 2022 HR@Moore Survey of Chief Human Resource Officers, we gathered information about the time and attention ELTs are paying towards ESG issues and the specific ESG initiatives occupying their time. We received responses on these items from 107 CHROs. We also asked CHROs for assessments of their company’s performance along a variety of dimensions relevant to ESG to provide further analysis on the connection between ESG initiatives and company impact

Wire scanners in low energy accelerators

Fast wire scanners are today considered as part of standard instrumentation in high energy synchrotrons. The extension of their use to synchrotrons working at lower energies, where Coulomb scattering can be important and the transverse beam size is large, introduces new complications considering beam heating of the wire, composition of the secondary particle shower and geometrical consideration in the detection set-up. A major problem in treating these effects is that the creation of secondaries in a thin carbon wire by a energetic primary beam is difficult to describe in an analytical way. We are here presenting new results from a full Monte Carlo simulation of this process yielding information on heat deposited in the wire, particle type and energy spectrum of secondaries and angular dependence as a function of primary beam energy. The results are used to derive limits for the use of wire scanners in low energy accelerators.Comment: 20 pages, 8 Postscript figures, uses elsart.cl

Psycholinguistic norms for more than 300 lexical signs in German Sign Language (DGS)

Sign language offers a unique perspective on the human faculty of language by illustrating that linguistic abilities are not bound to speech and writing. In studies of spoken and written language processing, lexical variables such as, for example, age of acquisition have been found to play an important role, but such information is not as yet available for German Sign Language (Deutsche Gebärdensprache, DGS). Here, we present a set of norms for frequency, age of acquisition, and iconicity for more than 300 lexical DGS signs, derived from subjective ratings by 32 deaf signers. We also provide additional norms for iconicity and transparency for the same set of signs derived from ratings by 30 hearing non-signers. In addition to empirical norming data, the dataset includes machine-readable information about a sign’s correspondence in German and English, as well as annotations of lexico-semantic and phonological properties: one-handed vs. two-handed, place of articulation, most likely lexical class, animacy, verb type, (potential) homonymy, and potential dialectal variation. Finally, we include information about sign onset and offset for all stimulus clips from automated motion-tracking data. All norms, stimulus clips, data, as well as code used for analysis are made available through the Open Science Framework in the hope that they may prove to be useful to other researchers: https://osf.io/mz8j4