Miracle-dz/UniFAR-FTUs huggingface dataset:
Electronic transport and consequences for material removal in ultrafast pulsed laser ablation of materials

Fast electronic transport is investigated theoretically based on a drift-diffusion approach for different classes of materials (metals, semiconductors, and dielectrics) under ultrafast, pulsed laser irradiation. The simulations are performed at intensities above the material removal threshold, characteristic for the ablation regime. The laser-induced charging of dielectric surfaces causes a subpicosecond electrostatic rupture of the superficial layers, an effect which, in comparison, is strongly inhibited for metals and semiconductors as a consequence of superior carrier transport properties.
Computer simulations of close encounters between single stars and hard binaries

We have simulated 5175 close encounters between hard binaries and single stars having masses M/sub 3/ ranging from 0.01 to 100 times the mass M/sub 1/ of the binary components. For all mass ratios the encounters lead to a net average fractional increase in the binding energy of the binary. For M/sub 3//M/sub 1/ approx. =0.7(M/sub 3//M/sub 1/). For M/sub 3//M/sub 1/> or approx. =3, approx. =3.1. The average recoil velocity of the single star after a close encounter increases from 0.84 of the initial orbital velocity of the binary for M/sub 3/ M/sub 1/. About two-thirds of the total recoil energy released in encounters at all impact parameters is produced by encounters in which the recoil velocity is less than the average recoil velocity at zero impact parameter. The probability that the impacting star will be a member of the post-encounter binary after a close encounter is virtually nonexistent if M/sub 3//M/sub 1/ 1.6. Except for a resonance-like peak in the transition zone between M/sub 3//M/sub 1/=0.2 and 1.6, the average post-encounter eccentricity increases monotonically with increasing values of M/sub 3//M/sub 1/. We usemore » the results of the computer simulations to compute improved cross sections governing the rate at which binaries feed kinetic energy into their parent star clusters. We compare these to earlier work. « less
A generalized heat conduction model in rarefied gas

After showing the failure of the traditional heat conduction law in describing correctly the heat flux phenomenon in a rarefied gas at the slip regime, a generalized heat conduction model is presented. The model predicts a heat conduction boundary layer near the wall with a thickness proportional to the Knudsen number. It reduces to the Fourier law when the Knudsen number is sufficiently small. An analytic solution from the present model shows satisfactory agreement with that from gas molecular-dynamics simulation.
From classical periodic orbits to the quantization of chaos

We present a quantitative analysis of Selberg’s trace formula viewed as an exact version of Gutzwiller’s semiclassical periodic-orbit theory for the quantization of classically chaotic systems. Two main applications of the trace formula are discussed in detail, (i) The periodic-orbit sum rules giving a smoothing of the quantal energy-level density. (ii) The Selberg zeta function as a prototype of a dynamical zeta function defined as an Euler product over the classical periodic orbits and its analytic continuation across the entropy barrier by means of a Dirichlet series. It is shown how the long periodic orbits can be effectively taken into account by a universal remainder term which is explicitly given as an integral over an ‘orbit-selection function’. Numerical results are presented for the free motion of a point particle on compact Riemann surfaces (Hadamard-Gutzwiller model), which is the primary testing ground for our ideas relating quantum mechanics and classical mechanics in the case of strong chaos. Our results demonstrate clearly the crucial role played by the long periodic orbits. An exact rule for quantizing chaos is derived for such systems where the Dirichlet series representing the Selberg zeta function converges on the critical line. Explicit formulae are given for the computation of the abscissae of absolute and conditional convergence, respectively, of these dynamical Dirichlet series. For the two Riemann surfaces considered, it turns out that one can cross the entropy barrier, but that the critical line cannot be reached by a convergent Dirichlet series. It would seem that this is the main reason why the Riemann-Siegel lookalike formula, recently conjectured by M. V. Berry and J. P. Keating, fails in generating the lower-lying quantal energies for these strongly chaotic systems.
Double-Jet Ejection of Cooling Air for Improved Film Cooling

Film cooling in gas turbines leads to aerodynamic mixing losses and reduced temperatures of the gas flow. Improvements of the gas turbine thermal efficiency can be achieved by reducing the cooling fluid amount and by establishing a more equal distribution of the cooling fluid along the surface. It is well known that vortex systems in the cooling jets are the origin of reduced film-cooling effectiveness. For the streamwise ejection case, kidney vortices result in a liftoff of the cooling jets; for the lateral ejection case, usually only one dominating vortex remains, leading to hot gas flow underneath the jet from one side. Based on the results of numerical analyses, a new cooling technology has been introduced by the authors, which reaches high film-cooling effectiveness as a result of a well-designed cooling hole arrangement for interaction of two neighboring cooling jets (double-jet film cooling (DJFC)). The results show that configurations exist, where an improved film-cooling effectiveness can be reached because an anti-kidney vortex pair is established in the double-jet. The paper aims at the following major contributions: (1) to introduce the DJFC as an alternative film-cooling technology to conventional film-cooling design; (2) to explain the major phenomena, which leads to the improvement of the film-cooling effectiveness by application of the DJFC; and (3) to prove basic applicability of the DJFC to a realistic blade cooling configuration and present the first test results under machine operating conditions.
Methods for Estimating Climate Anomaly Forcing Patterns

AbstractInverse methods for determining the anomalous mean forcing functions responsible for climate change are investigated. First, an iterative method is considered, and it is shown to successfully reproduce forcing functions for various idealized and observed climate states using quasigeostrophic simulations. Second, a new inverse method that is more computationally efficient is presented. This method closes the mean-field equations by representing the second-order statistical moments, the transient eddy heat and momentum (or potential vorticity) fluxes, as linear functions of the mean field. The coefficients of the linear parameterization are determined by least squares regression. It is shown that the new method also successfully reproduces the anomalous forcing functions responsible for climatic changes in quasigeostrophic simulations.
Evaluation of stress caused by drying-off dairy cows and its relation to milk yield and udder pressure

Most measurements of udder pressure are based on devices connected to the gland cistern via cannulas. These devices are either inserted in the teat canal or surgically implanted into the udder tissue. In this study, instead of invasively measuring intramammary udder pressure, we measured the udder firmness noninvasively on the udder surface via a dynamometer. These are commonly used in food research to determine crispiness and firmness of fruits. The objective of this study was to validate a hand-held dynamometer for measuring udder firmness in dairy cows. Specifically we set out to determine interinvestigator repeatability considering potential confounders such as investigator, location, and cow. Through modifications in the standard operating procedure for the measurements, interinvestigator repeatability increased from correlation coefficient = 0.80 (n = 275) to correlation coefficient = 0.94 (n = 634). Measurements in different locations within the left hind quarter revealed a firmness gradient from the upper to the lower measuring point. Measurements between the 4 quarters within a cow displayed differences, except between both hind quarters. In 94.8% of the udders, firmness decreased due to milking. The correlation coefficient, however, between firmness changes and milk yield was low (r = 0.42, n = 153). Our data provide evidence that the dynamometer, although imperfect, does provide a reasonable measure of udder firmness and can be a useful tool in research related to animal health and welfare. However, a standardized operating protocol should be followed to minimize confounding by investigator, location, and quarter.
Influence of Polymer Processing on the Double Electrical Percolation Threshold in PLA/PCL/GNP Nanocomposites

For the first time, the double electrical percolation threshold was obtained in polylactide (PLA)/polycaprolactone (PCL)/graphene nanoplatelet (GNP) composite systems, prepared by compression moulding and fused filament fabrication (FFF). Using scanning electron microscopy (SEM) and atomic force microscopy (AFM), the localisation of the GNP, as well as the morphology of PLA and PCL phases, were evaluated and correlated with the electrical conductivity results estimated by the four-point probe method electrical measurements. The solvent extraction method was used to confirm and quantify the co-continuity in these samples. At 10 wt. % of the GNP, compression-moulded samples possessed a wide co-continuity range, varying from PLA55/PCL45 to PLA70/PCL30. The best electrical conductivity results were found for compression-moulded and 3D-printed PLA65/PCL35/GNP that have the fully co-continuous structure, based on the experimental and theoretical findings. This composite owns the highest storage modulus and complex viscosity at low angular frequency range, according to the melt shear rheology. Moreover, it exhibited the highest char formation and polymers degrees of crystallinity after the thermal investigation by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. The effect of the GNP content, compression moulding time, and multiple twin-screw extrusion blending steps on the co-continuity were also evaluated. The results showed that increasing the GNP content decreased the continuity of the polymer phases. Therefore, this work concluded that polymer processing methods impact the electrical percolation threshold and that the 3D printing of polymer composites entails higher electrical resistance as compared to compression moulding.
Associations between Suicidal Ideation and Relatives’ Physical and Mental Health among Community Residents: Differences between Family Members and Lineal Consanguinity

(1) Background: Despite the verified relationship between relatives’ characteristics and individual suicidal ideation, few studies have discussed the role of family members and lineal consanguinity independently according to whether they live together with the individuals or not. (2) Methods: The data in this study were collected in November 2019 and identified rural adults over 18 years old in Shandong as the survey objects, with a total of 879 valid cases included in this survey. Logistic regression analysis was employed to examine the risk factors affecting adults’ suicidal ideation and differentiate the effects of a family member and lineal consanguinity’s physical and mental health. Relatives’ physical and mental health were estimated by three aspects: whether they were suffering from chronic diseases, mental illness, or alcoholism. (3) Results: The study showed that a family member’s physical (OR = 2.303, p < 0.01) and mental health (OR = 5.877, p < 0.05) was related to suicidal ideation, but the association between lineal consanguinities’ physical and mental health and suicidal ideation were not supported. People over 40 years old (OR = 6.528, p < 0.05), from only-child families (OR = 4.335, p < 0.01), with household indebtedness (OR = 2.992, p < 0.001), or difficulty falling asleep (OR = 3.165, p < 0.001) had risk factors of suicidal ideation. (4) Conclusions: The physical and mental health of individuals’ family members are related to their suicidal ideation, and their lineal consanguinities’ physical and mental health are not related to suicidal ideation. These findings imply the different associations between family environment, genetic factors, and suicidal ideation. Family members’ health should be considered as a factor to prevent and control suicidal behaviors, including suicidal ideation.
Significance of the Work Environment and Personal Resources for Employees’ Well-Being at Work in the Hospitality Sector

The aim of the study was to investigate whether different elements of the work environment (manifested by job demands, job control, and social support) and personal resources were linked to employees’ well-being at work. Based on data gathered from 574 employees in the hospitality industry in Serbia, it was also tested if personal resources, expressed through self-efficacy, hope, optimism, and resilience, could moderate the relationship between work environment and employees’ well-being at work. Correlation analyses showed that high job demands had negative effects on employees’ well-being, causing negative emotional reactions to their job, while job control and social support developed positive relationships with positive employees’ well-being. The moderating effect analysis found that personal resources can fully moderate the relationship between job demands and well-being at work, and job control and well-being at work. On the other side, personal resources were not a significant moderator in the relationship between social support and well-being at work, indicating that even when employees have adequate personal resources, they are not enough to decrease the negative effects of lack of social support on employees’ well-being at work. This shows how important the support of supervisors and colleagues is for employees in hospitality.
Leave Graphs Alone: Addressing Over-Squashing without Rewiring

Recent works have investigated the role of graph bottlenecks in preventing long-range information propagation in message-passing graph neural networks, causing the so-called `over-squashing' phenomenon. As a remedy, graph rewiring mechanisms have been proposed as preprocessing steps. Graph Echo State Networks (GESNs) are a reservoir computing model for graphs, where node embeddings are recursively computed by an untrained message-passing function. In this paper, we show that GESNs can achieve a significantly better accuracy on six heterophilic node classification tasks without altering the graph connectivity, thus suggesting a different route for addressing the over-squashing problem.
Diffuse auroral electron scattering by electron cyclotron harmonic and whistler mode waves during an isolated substorm

There are two main theories for the origin of diffuse auroral electron precipitation: precipitation by electrostatic ECH waves and precipitation by whistler mode waves. Here we analyze a case event where whistler mode hiss, chorus, and ECH waves are intensified during a weak substorm injection event to identify the source of particle precipitation. Examination of the particle data shows that there are three sources of free energy: a temperature anisotropy, a loss cone, and a pancake distribution. Instability analysis shows that the temperature anisotropy excites whistler mode hiss whereas both the temperature anisotropy and the pancake distribution contribute to the excitation of chorus. ECH waves are driven unstable by the loss cone. Wave propagation studies show that the path integrated gain of hiss and chorus is almost unaffected by changes in the depth of the loss cone, whereas ECH waves are very sensitive. Analysis of the changes in the resonant energy during propagation shows that the hiss resonates with electrons above a few keV while chorus resonates below a few hundred eV. As a result, neither hiss nor chorus are likely to cause significant electron precipitation from a few hundred eV to a few keV for this event. On the other hand, ECH waves resonate with electrons in the energy range between that for chorus and hiss. ECH waves can scatter electrons with pitch angles of up to 80 degrees into the loss cone. We conclude that ECH waves are responsible for the formation of the pancake distribution and are probably the main component of diffuse auroral precipitation during this event. We suggest that substorm-injected electrons are responsible for the intensification of hiss and ECH waves and that rapid scattering of electrons by ECH waves forms the pancake distribution which then excites chorus. We also suggest that rapid pitch angle scattering by ECH waves could be responsible for double frequency banded chorus emissions.
Inhibitory Actions of Clinical Analgesics, Analgesic Adjuvants, and Plant-Derived Analgesics on Nerve Action Potential Conduction

The action potential (AP) conduction in nerve fibers plays a crucial role in transmitting nociceptive information from the periphery to the cerebral cortex. Nerve AP conduction inhibition possibly results in analgesia. It is well-known that many analgesics suppress nerve AP conduction and voltage-dependent sodium and potassium channels that are involved in producing APs. The compound action potential (CAP) recorded from a bundle of nerve fibers is a guide for knowing if analgesics affect nerve AP conduction. This entry mentions the inhibitory effects of clinically used analgesics, analgesic adjuvants, and plant-derived analgesics on fast-conducting CAPs and voltage-dependent sodium and potassium channels. The efficacies of their effects were compared among the compounds, and it was revealed that some of the compounds have similar efficacies in suppressing CAPs. It is suggested that analgesics-induced nerve AP conduction inhibition may contribute to at least a part of their analgesic effects.
Network Architecture Search and Expert Designed CNNs for Multi-target Concrete Defect Detection

—In this project, we focus at the problem of bridge crack detection in CODEBRIM dataset for assessing the structural integrity in multi-target scenario. We compare two branches of convolutional neural networks (CNNs): expert-designed complex CNNs (e.g. VGG, ResNet, AlexNet) and automatically generated lightweight CNNs from network architecture search (NAS). For the latter, we introduce three NAS methods driven by different data source: in-domain models searched in CODEBRIM dataset, transferred models searched in ImageNet dataset and data-free zero-shot models. Further, we show that cross-domain transfer learning greatly boost our models’ performance (ZenNAS-1 model from 69.5% to 75.6%), which surpassed all expert-designed models with much fewer parameters (134.28M from VGG-D to 5.43M from ZenNAS-1). We validate such performance gain via studying the attention distribution of convolutional ﬁlters using Grad-CAM on image samples of different cracks.
Generalized few-shot node classification: toward an uncertainty-based solution

For real-world graph data, the node class distribution is inherently imbalanced and long-tailed, which naturally leads to a few-shot learning scenario with limited nodes labeled for newly emerging classes. There are many carefully designed solutions for such a few-shot learning problem via methods such as data augmentation, learning transferable initialization, learning prototypes, and many more. However, most, if not all, of them are based on a strong assumption that all the test nodes exclusively come from novel classes, which is impractical in real-world applications. In this paper, we study a broader and more realistic problem named generalized few-shot node classification , where the test samples can be from both novel classes and base classes. Compared with the standard few-shot node classification, this new problem imposes several unique challenges, including asymmetric classification and inconsistent preference . To counter those challenges, we propose a shot-aware neural node classifier ( Stager ) equipped with an uncertainty-based weight assigner module for adaptive propagation. As the existing meta-learning solutions cannot handle this new problem, we propose a novel training paradigm named imbalanced episodic training to ensure the label distribution is consistent between the meta-training and meta-test scenarios. Comprehensive experiments on four real-world datasets demonstrate the effectiveness of our proposed model and training paradigm.
When are capital structure decisions nonseparable from production planning? : the case of generalized royalty-based hybrid finance

The well-known result that capital structure is irrelevant for firm value follows from a set of assumptions conducive to theoretical analysis. In this note we explore the implications of relaxing one of these assumptions: the independence of cash flows from capital structure. Unlike debt and equity, funding that is accompanied by a royalty payment obligation has the effect of increasing marginal cost, to which a profit-maximizing firm responds by reducing output, violating the independence assumption. We study the effect on optimal production plans of generalized royalty payment obligations in which the royalty rate need not be constant across partitions of cumulative output, resulting in piece-wise linear cumulative royalty schedules that are not everywhere differentiable. The associated optimization problem for intertemporal production planning is nonstandard as it is not time separable. Here we solve this nonstandard problem by formulating an equivalent problem that in turn can be solved by the Pontryagin Maximum Principle using numerical techniques. When generalized royalty-based finance is included in the financing mix, the optimal production plan is non-trivially related to capital structure and capital structure is relevant to firm value. Unless the financing mix is restricted to debt and equity, financing decisions and production planning decisions cannot be undertaken independently in general.
Signature effects in two Quasi-Particle rotational bands of Odd-Odd Deformed Nuclei

The two quasi-particle (2qp) excitations in odd-odd deformed nuclei exhibit varieties of high spin features such as back bending, band crossing, band termination, signature splitting and signature inversion etc. The signature effects exhibited by these bands have attracted a considerable attention from theoretical as well as from experimental aspects, which lead to the emergence of different possible explanations for these effects [1-4]. In present thesis, we adopted axially symmetric Two Quasi-Particle plus Rotor Model (TQPRM) [4] to investigate the role of Coriolis and particle-particle mixing in explaining signature effects observed in 2qp rotational bands of odd-odd deformed nuclei.