Miracle-dz/UniFAR-FTUs huggingface dataset:
Stacked slantwise convective circulations

It is well known that classical (ana) cold fronts tend to be characterized by mesoscale circulations in which upright line convection feeds a layer of concentrated rearward slantwise ascent. Occasionally, however, as in the case‐study presented in this paper, two and sometimes more of these mesoscale circulations coexist within the same cold‐frontal zone. The two slantwise circulations described were observed to be stacked one above the other with a vertical wavelength of less than 2 km. Although it is often suspected that the circulations at ana‐cold fronts are enhanced by mesoscale processes such as conditional symmetric instability (CSI) or ΔM‐adjustment, it is notoriously difficult to discriminate between these circulations and the larger‐scale transverse circulation within which they are embedded. The occurrence in this study of multiple circulations with small vertical scale helps to distinguish them from the large‐scale circulation, and this has motivated the detailed examination of this case.
Design of a detection coil system for a biaxial vibrating sample magnetometer and some applications

A theoretical expression for the sensitivity of a detection coil for a vibrating sample magnetometer (VSM) is derived. This expression is used to design a detection coil system for a biaxial VSM for measuring the magnetization components in the direction of the applied field (x direction) and perpendicular to the applied field (y direction). This detection coil system is optimized with respect to the sensitivity, cross talk, and their position dependences. Both an eight‐coil detection system and a 12‐coil detection system are described. With the eight‐coil detection system, experiments have been performed showing that, in an electromagnet VSM, images contribute significantly to the measured signals. The 12‐coil configuration has the lowest position dependences and cross talk. An example shows that the average position dependences in the xy plane can be five times better compared to the eight‐coil configuration with comparable sensitivities. For both detection directions the signal varies less than 1% with.
Ultrafast internal thermalization of photoexcited carriers in polar semiconductors

We present a combined experimental and theoretical study of the ultrafast internal thermalization of high energy carriers created by laser excitation. Luminescence up-conversion is used to monitor the spectral and temporal evolution of the photoexcited carrier distributions with a time resolution of about 100 fs. A Monte Carlo simulation joined with a molecular dynamics approach is then used to interpret the experimental results. We show that the coulomb interaction among carriers is responsible for the initial ultrafast thermalization. The simulation allow us to distinguish between binary carrier-carrier collisions and plasmon losses and reconcile the results obtained with time resolved vs. c.w. hot (e, angstroms) luminescence.
Parameter Estimation for Bivariate Shock Models with Singular Distribution for Censored Data with Concomitant Order Statistics

When two‐component parallel systems are tested, the data consist of Type‐II censored data X(i), i= 1, n, from one component, and their concomitants Y [i] randomly censored at X(r), the stopping time of the experiment. Marshall & Olkin's (1967) bivariate exponential distribution is used to illustrate statistical inference procedures developed for this data type. Although this data type is motivated practically, the likelihood is complicated, and maximum likelihood estimation is difficult, especially in the case where the parameter space is a non‐open set. An iterative algorithm is proposed for finding maximum likelihood estimates. This article derives several properties of the maximum likelihood estimator (MLE) including existence, uniqueness, strong consistency and asymptotic distribution. It also develops an alternative estimation method with closed‐form expressions based on marginal distributions, and derives its asymptotic properties. Compared with variances of the MLEs in the finite and large sample situations, the alternative estimator performs very well, especially when the correlation between X and Y is small.
A kinematic model of a ducted flame

A premixed ducted flame, burning in the wake of a bluff-body flame-holder, is considered. For such a flame, interaction between acoustic waves and unsteady combustion can lead to self-excited oscillations. The concept of a time-invariant turbulent flame speed is used to develop a kinematic model of the response of the flame to flow disturbances. Variations in the oncoming flow velocity at the flame-holder drive perturbations in the flame initiation surface and hence in the instantaneous rate of heat release. For linear fluctuations, the transfer function between heat release and velocity can be determined analytically from the model and is in good agreement with experiment across a wide frequency range. For nonlinear fluctuations, the model reproduces the flame surface distortions seen in schlieren films. Coupling this kinematic flame model with an analysis of the acoustic waves generated in the duct by the unsteady combustion enables the time evolution of disturbances to be calculated. Self-excited oscillations occur above a critical fuel–air ratio. The frequency and amplitude of the resulting limit cycles are in satisfactory agreement with experiment. Flow reversal is predicted to occur during part of the limit-cycle oscillation and the flame then moves upstream of the flame-holder, just as in experimental visualizations. The main nonlinearity is identified in the rate of heat release, which essentially ‘saturates’ once the amplitude of the velocity fluctuation exceeds its mean. We show that, for this type of nonlinearity, describing function analysis can be used to give a good estimate of the limit-cycle frequency and amplitude from a quasi-nonlinear theory.
The fading problem and the population of the Oort cloud

Context. The discovery efficiency of the dynamically new comets has been assumed to be approximately the same as that of all long-period (LP) comets when estimating the population of the Oort cloud. On the other hand, studies of the so-called fading problem have implied a strong difference in the discovery efficiencies of both new and old comets. Some authors have attempted to explain this discrepancy by suggesting that old comets disappeared due to the extinction or disintegration of their nuclei. Aims. We attempt to answer the question of whether the absolute brightness of old comets steeply decreases in time or whether their nuclei become extinct, dormant, or disintegrated. Moreover, we analyse the impact of the highly different discovery efficiencies on an estimate of the Oort-cloud population. Methods. The dominance of the fading over the extinction, dormant-phase, or disintegration is demonstrated with the help of the distributions of the reciprocal semi-major axes of the original orbits of the LP comets and a more moderate decrease in discoveries of new comets with increasing perihelion distance. The comet discoveries within the LINEAR sky survey are also used to support our conclusion. Results. The demonstrated dominance of the fading implies the relatively higher discovery efficiency of new comets. Its ignorance causes an overestimation of the actual intrinsic flux of new comets through the zone of visibility compared to the corresponding intrinsic flux of all LP comets. This overestimate is also documented by a significantly smaller amount of new comets with perihelia $q \loa 3\,$AU discovered within the LINEAR. Conclusions. The actual intrinsic flux of new comets must be about one order of magnitude lower than has been derived before. Its reduction implies a one-order-of-magnitude less numerous population for the Oort cloud. Moreover, such the reduction also solves (or, at least, weakens) the problem of too high a mass of the comet cloud, as well as the problem of too numerous a population of predicted Halley-type objects or too high a space density of interstellar comets.
Bianchi cosmologies: the role of spatial topology

The role of spatial topology in the Hamiltonian description of Bianchi models is analysed. It turns out that, in general, the number of degrees of freedom of these models is not uniquely determined by the isometry group but depends in addition on the choice of topology. Consequently, the quantum theory is quite sensitive to this choice. Contrary to one's initial expectation, subtleties arise in the spatially open models-say with topology R3-rather than closed. Finally, it is shown that class B models cannot occur with closed topologies.
Errors in simultaneous measurements of temperature and velocity in the outer part of a heated jet

Simultaneous measurements of velocity and temperature fluctuations in the outer part of a heated circular jet discharged into still air may be in error as a result of reverse flow regions and the inevitable contamination of the cold (temperature) wire signal by the thermal wake of the hot wire. The error in mean and rms temperature is estimated for the case of two standard hot wire‐cold wire arrangements. At the half‐temperature radius, the mean and rms temperature are overestimated by about 16% and 46%, respectively. Conditional measurements of velocity fluctuations are also presented as a first attempt to obtain velocity statistics without the effect of reverse flow regions. Measured normalized moments of the velocity fluctuation are larger than the ’’corrected’’ values, the difference increasing with the order of the moment and with radial distance in the outer part of the jet.
Optimal sensor and actuator location for unstable systems

Accurate and reliable process measurements play a key role in the success of process control. In addition to selecting the instrumentation hardware, it is important to determine which variables should be measured in a process. Therefore it is important to study techniques for placing sensors on the processes. Dually the problem of placing actuators on the processes is equally important. In this paper, the problem of determining optimal sensor and actuator locations for the linear systems is addressed. The problem of the sensor locations is viewed as the problem of maximizing the output energy generated by a given state and for the actuator locations is viewed as the problem of minimizing the input energy required to reach a given state. Such design problems occur in many applications, and therefore have been studied extensively. Unfortunately, the results in this context, which have been proposed so far, only support stable systems. However, in industrial practices it is often the case that the system, which is needed to be controlled, is not stable. The method which is proposed in this paper is a general method in the sense that it supports both stable and unstable systems. The technique is successfully used for determining the optimal sensor locations of the linearized Continuous Stirred-Tank Reactor unstable model.
Educator's blueprint: A how‐to guide for collecting validity evidence in survey‐ based research

Surveys are descriptive assessment tools. Like other assessment tools, the validity and reliability of the data obtained from surveys depend, in large part, on the rigor of the development process. Without validity evidence, data from surveys may lack meaning, leading to uncertainty as to how well the survey truly measures the intended constructs. In documenting the evidence for the validity of survey results and their intended use, it is incumbent on the survey creator to have a firm understanding of validity frameworks. Having an understanding of validity evidence and how each step in the survey development process can support the validity argument makes it easier for the researcher to develop, implement, and publish a high‐quality survey.
Diagnosis of Scoliosis Using Chest Radiographs with a Semi-Supervised Generative Adversarial Network

Purpose To develop and validate a deep learning-based screening tool for the early diagnosis of scoliosis using chest radiographs with a semi-supervised generative adversarial network (GAN). Materials and Methods Using a semi-supervised learning framework with a GAN, a screening tool for diagnosing scoliosis was developed and validated through the chest PA radiographs of patients at two different tertiary hospitals. Our proposed method used training GAN with mild to severe scoliosis only in a semi-supervised manner, as an upstream task to learn scoliosis representations and a downstream task to perform simple classification for differentiating between normal and scoliosis states sensitively. Results The area under the receiver operating characteristic curve, negative predictive value (NPV), positive predictive value, sensitivity, and specificity were 0.856, 0.950, 0.579, 0.985, and 0.285, respectively. Conclusion Our deep learning-based artificial intelligence software in a semi-supervised manner achieved excellent performance in diagnosing scoliosis using the chest PA radiographs of young individuals; thus, it could be used as a screening tool with high NPV and sensitivity and reduce the burden on radiologists for diagnosing scoliosis through health screening chest radiographs.
Improving polymer light-emitting diodes efficiency using interlayers based on cross-linkable polymers

The efficiency of light-emitting diodes based on poly[(2-methoxy)-5-(2′-ethyl-hexyloxy)-1,4-phenylenevinylene] increases upon formation of interlayers, on top of poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonic acid (PEDOT:PSS), made of acid-initiated cross-linkable polyfluorenes. The use of this type of polymers allows for the formation of thicker interlayers leading to higher efficiencies when comparing with similar devices with interlayers formed by the parent non-cross-linkable polymers. This efficiency increase is attributed to a combination of electron and exciton confinement away from PEDOT:PSS.
WEIGHTED SUMS OF CERTAIN DEPENDENT RANDOM VARIABLES

1. Let be a probability space and,be an increasing family of sub o'-fields of(we put(c) Let (xn)n=1, 2, •c be a sequence of bounded martingale differences on , that is,xn(ƒÖ) is bounded almost surely (a.s.) ands. for n =1, 2,. It is easily seen that this sequence has the following properties[G] and [M], which have been introduced by Y. S. Chow ([1]) in an analogous form and by G. Alexits ([4]), respectively, and may be of independent interest.
Protective effects and therapeutic applications of ellagic acid against natural and synthetic toxicants: A review article

Traditional herbal drugs are widely used for the treatment of various diseases. Ellagic acid (EA) as an herbal polyphenol metabolite exists in many medicinal plants. EA has an important role against natural and chemical toxicities due to its antioxidant and anti-inflammatory properties. For this review, several search engines or databases such as PubMed, Scopus, the Web of Science, and Google Scholar were used, and the most relevant published papers till February 2022 were included. The protective effects of EA against natural and chemical compounds are mediated through molecular mechanisms including scavenging of free radicals, modulation of proinflammatory cytokine synthesis, and reduction of lipid peroxidation. These properties make EA a highly fascinating compound that may contribute to different aspects of health; whereas, more studies are needed, especially on the pharmacokinetic profile of EA. In this review, we selected articles that include the protective effect of EA against several synthetic and natural toxins such as aflatoxin, lipopolysaccharide, acrylamide, and rotenone.
A Self-Adaptive Strategy for the Time Integration of Navier-Stokes Equations

An efficient self-adaptive strategy for the explicit time integration of Navier-Stokes equations is presented. Unlike the conventional explicit integration schemes, it is not based on a standard CFL condition. Instead, the eigenvalues of the dynamical system are analytically bounded and the linear stability domain of the time-integration scheme is adapted in order to maximize the time step. The method works independently of the underlying spatial mesh; therefore, it can be easily integrated into structured or unstructured codes. The additional computational cost is minimal, and a significant increase of the time step is achieved without losing accuracy. The effectiveness and robustness of the method are demonstrated on both a Cartesian staggered and an unstructured collocated formulation. In practice, CPU cost reductions up to more than 4 with respect to the conventional approach have been measured.
An Elementary Approach to Local Solvability for Constant Coefficient Partial Differential Equations

We give an elementary proof of local solvability for constant coefficient partial differential equations, P(D)u=f, for square-integrable functions/. The proof uses only PlancherePs theorem and elementary facts about Hubert spaces. We then deduce the best lower bounds for the L norm of P (D) for test functions . 1980 Mathematics Subject Classification (1985 Revision): 35A07 §
Body mass index and childhood symptoms of depression, anxiety, and attention-deficit hyperactivity disorder: A within-family Mendelian randomization study

Background: Higher BMI in childhood is associated with emotional and behavioural problems, but these associations may not be causal. Results of previous genetic studies imply causal effects but may reflect influence of demography and the family environment. Methods: This study used data on 40,949 8-year-old children and their parents from the Norwegian Mother, Father and Child Cohort Study (MoBa) and Medical Birth Registry of Norway (MBRN). We investigated the impact of BMI on symptoms of depression, anxiety, and attention-deficit hyperactivity disorder (ADHD) at age 8. We applied within-family Mendelian randomization, which accounts for familial effects by controlling for parental genotype. Results: Within-family Mendelian randomization estimates using genetic variants associated with BMI in adults suggested that a child’s own BMI increased their depressive symptoms (per 5 kg/m2 increase in BMI, beta = 0.26 S.D., CI = −0.01,0.52, p=0.06) and ADHD symptoms (beta = 0.38 S.D., CI = 0.09,0.63, p=0.009). These estimates also suggested maternal BMI, or related factors, may independently affect a child’s depressive symptoms (per 5 kg/m2 increase in maternal BMI, beta = 0.11 S.D., CI:0.02,0.09, p=0.01). However, within-family Mendelian randomization using genetic variants associated with retrospectively-reported childhood body size did not support an impact of BMI on these outcomes. There was little evidence from any estimate that the parents’ BMI affected the child’s ADHD symptoms, or that the child’s or parents’ BMI affected the child’s anxiety symptoms. Conclusions: We found inconsistent evidence that a child’s BMI affected their depressive and ADHD symptoms, and little evidence that a child’s BMI affected their anxiety symptoms. There was limited evidence of an influence of parents’ BMI. Genetic studies in samples of unrelated individuals, or using genetic variants associated with adult BMI, may have overestimated the causal effects of a child’s own BMI. Funding: This research was funded by the Health Foundation. It is part of the HARVEST collaboration, supported by the Research Council of Norway. Individual co-author funding: the European Research Council, the South-Eastern Norway Regional Health Authority, the Research Council of Norway, Helse Vest, the Novo Nordisk Foundation, the University of Bergen, the South-Eastern Norway Regional Health Authority, the Trond Mohn Foundation, the Western Norway Regional Health Authority, the Norwegian Diabetes Association, the UK Medical Research Council. The Medical Research Council (MRC) and the University of Bristol support the MRC Integrative Epidemiology Unit.
An immersed-boundary finite-volume method for simulations of flow in complex geometries

Abstract A new immersed-boundary method for simulating flows over or inside complex geometries is developed by introducing a mass source/sink as well as a momentum forcing. The present method is based on a finite-volume approach on a staggered mesh together with a fractional-step method. Both momentum forcing and mass source are applied on the body surface or inside the body to satisfy the no-slip boundary condition on the immersed boundary and also to satisfy the continuity for the cell containing the immersed boundary. In the immersed-boundary method, the choice of an accurate interpolation scheme satisfying the no-slip condition on the immersed boundary is important because the grid lines generally do not coincide with the immersed boundary. Therefore, a stable second-order interpolation scheme for evaluating the momentum forcing on the body surface or inside the body is proposed. Three different flow problems (decaying vortices and flows over a cylinder and a sphere) are simulated using the immersed-boundary method proposed in this study and the results agree very well with previous numerical and experimental results, verifying the accuracy of the present method.
Opposing effects of trans‐ and cis‐cinnamic acid during rice coleoptile elongation

Abstract The phenylpropanoid cinnamic acid (CA) is a plant metabolite that can occur under a trans‐ or cis‐form. In contrast to the proven bioactivity of the cis‐form (c‐CA), the activity of trans‐CA (t‐CA) is still a matter of debate. We tested both compounds using a submerged rice coleoptile assay and demonstrated that they have opposite effects on cell elongation. Notably, in the tip of rice coleoptile t‐CA showed an inhibiting and c‐CA a stimulating activity. By combining transcriptomics and (untargeted) metabolomics with activity assays and genetic and pharmacological experiments, we aimed to explain the underlying mechanistic processes. We propose a model in which c‐CA treatment activates proton pumps and stimulates acidification of the apoplast, which in turn leads to the loosening of the cell wall, necessary for elongation. We hypothesize that c‐CA also inactivates auxin efflux transporters, which might cause a local auxin accumulation in the tip of the coleoptile. For t‐CA, the phenotype can partially be explained by a stimulation of cell wall polysaccharide feruloylation, leading to a more rigid cell wall. Metabolite profiling also demonstrated that salicylic acid (SA) derivatives are increased upon t‐CA treatment. As SA is a known antagonist of auxin, the shift in SA homeostasis provides an additional explanation of the observed t‐CA‐mediated restriction on cell growth.
New generation of human machine interfaces for controlling UAV through depth-based gesture recognition

New forms of natural interactions between human operators and UAVs (Unmanned Aerial Vehicle) are demanded by the military industry to achieve a better balance of the UAV control and the burden of the human operator. In this work, a human machine interface (HMI) based on a novel gesture recognition system using depth imagery is proposed for the control of UAVs. Hand gesture recognition based on depth imagery is a promising approach for HMIs because it is more intuitive, natural, and non-intrusive than other alternatives using complex controllers. The proposed system is based on a Support Vector Machine (SVM) classifier that uses spatio-temporal depth descriptors as input features. The designed descriptor is based on a variation of the Local Binary Pattern (LBP) technique to efficiently work with depth video sequences. Other major consideration is the especial hand sign language used for the UAV control. A tradeoff between the use of natural hand signs and the minimization of the inter-sign interference has been established. Promising results have been achieved in a depth based database of hand gestures especially developed for the validation of the proposed system.