Miracle-dz/UniFAR-FTUs huggingface dataset:
On the porous‐continuum modeling of gravity‐driven fingers in unsaturated materials: Extension of standard theory with a hold‐back‐pile‐up effect

The traditional Richards equation (RE) in combination with standard monotonic properties (constitutive relations and hysteretic equations of state) has been shown to lack critical physics required to model gravity‐driven fingering (GDF). We extend the RE with an experimentally observed hold‐back‐pile‐up (HBPU) effect not captured in the standard porous‐continuum RE formulation. We postulate the HBPU effect is tied to wetting front sharpness and can be mathematically formulated in a variety of ways to include hypodiffusive, hyperbolic, and mixed spatial‐temporal forms involving respectively a Laplacian, a second‐order derivative in time, and a Laplacian of a first‐order derivative in time of the state variables. For each, we can infer an extended flux relation comprised of the Darcy‐Buckingham flux plus an additional component due to the HBPU effect. Extended flux relations that are mathematically similar to each can be found in the single‐phase and multiphase flow literature, however, all with very different underlying conceptualizations of the possible physics.
Universal principles for Kazdan-Warner and Pohozaev-Schoen type identities

The classical Pohozaev identity constrains potential solutions of certain semilinear PDE boundary value problems. The Kazdan-Warner identity is a similar necessary condition important for the Nirenberg problem of conformally prescribing scalar curvature on the sphere. For dimensions $n\geq 3$ both identities are captured and extended by a single identity, due to Schoen in 1988. In each of the three cases the identity requires and involves an infinitesimal conformal symmetry. For structures with such a conformal vector field, we develop a very wide, and essentially complete, extension of this picture. Any conformally variational natural scalar invariant is shown to satisfy a Kazdan-Warner type identity, and a similar result holds for scalars that are the trace of a locally conserved 2-tensor. Scalars of the latter type are also seen to satisfy a Pohozaev-Schoen type identity on manifolds with boundary, and there are further extensions. These phenomena are explained and unified through the study of total and conformal variational theory, and in particular the gauge invariances of the functionals concerned. Our generalisation of the Pohozaev-Schoen identity is shown to be a complement to a standard conservation law from physics and general relativity.
CEO mandate and age in the comparability of financial statements

The present study analyses the influence of mandate time and Chief Executive Officer (CEO) age on comparability in Brazilian market publicly traded companies. In a yearly basis, 58 companies were analyzed from 2013 to 2019. Data were submitted to panel data regression which indicated mandate influences comparability in a positive way. It was also found that CEO age does not exert a direct influence on comparability although it is a personal characteristic acting indirectly as a moderator factor in the relation between mandate and comparability. Younger CEOs tend to decrease comparability of accounting information during their mandate. The study is important since it demonstrates that changes on accounting choices are more aggressive in the beginning and slow down as mandate increases. Another important aspect, in practical field, refers to the evidence that CEO age potentiates mandate influence on comparability.
Delays of optical bursts in simultaneous optical and X-ray observations of MXB 1636-53

Observations of simultaneous optical and X-ray bursts from 4U/MXB 1636-53 were made using the Hakucho burst monitor system and optical telescopes at the European Southern Observatory during 1979 and 1980. The six best cases among the 10 coinciding observations are analyzed in terms of a model in which the optical emission is the result of reprocessing of X-rays (through blackbody heating). From this analysis, the temperature (spatially averaged) and size of a reprocessor, and the smearing and delay of the optical bursts are obtained. For the maximum temperatures of the optical reprocessor, the values differ from burst to burst, ranging from about 3 x 10 to the 4th to about 10 to the 5th K. The present analysis suggests that the size of the reprocessor varies by a factor of a few. For the smearing of the optical bursts an upper limit of a few seconds is derived. The most important result of this analysis is that the delay times are not the same for all bursts. The possible constraints which these results put on a low-mass binary model of this burst source are discussed.
Persistence of earnings and the fair value in non-financial companies: evidence from Latin America

Previous studies that linked earnings persistence to the presence of assets measured at fair value investigated financial companies in more developed markets, who found evidence that the use of fair value improves earnings persistence. In this study, the relationship between earnings persistence and the presence of assets measured at fair value of non-financial companies in Latin America was investigated, confirming the originality of the research. Regressions with panel data were applied to a sample of non-financial companies from 2010 to 2018. The results of this work indicate that there is a lower persistence of earnings for non-financial companies that use fair value, regardless of the level of the hierarchy, resulting in loss of predictive ability of earnings when associated with fair value. These results can be useful to analysts, investors, and other stakeholders who use accounting for performance forecasting purposes. Finally, this study can further encourage the discussion about the use of fair value in accounting.
AN ELEMENTARY AND CONSTRUCTIVE SOLUTION TO HILBERT'S 17TH PROBLEM FOR MATRICES

We give a short and elementary proof of a theorem of Procesi, Schacher and (independently) Gondard, Ribenboim that generalizes a famous result of Artin. Let A be an n x n symmetric matrix with entries in the polynomial ring R[x 1 ,. ,x m ]. The result is that if A is positive semidefinite for all substitutions (x 1 ,.,x m ) ∈ R m , then A can be expressed as a sum of squares of symmetric matrices with entries in R(x 1 ,.,x m ). Moreover, our proof is constructive and gives explicit representations modulo the scalar case.
Extracting Attributes for Twitter Hashtag Communities

—Various organisations often need to understand discussions on social media, such as what trending topics are and characteristics of the people engaged in the discussion. A number of approaches have been proposed to extract attributes that would characterise a discussion group. However, these approaches are largely based on supervised learning, and as such they require a large amount of labelled data. We propose an approach in this paper that does not require labelled data, but rely on lexical sources to detect meaningful attributes for online discussion groups. Our ﬁndings show an acceptable level of accuracy in detecting attributes for Twitter discussion groups.
RRU_A_307541 251..256

1Department of Radiology, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam; 2Department of Surgery, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam; 3Department of Histology, Embryology, Pathology and Forensic Medicine, Hue University of Medicine and Pharmacy, Hue University, Hue, Vietnam Abstract: The coexistence of multiple synchronous primary malignancies is uncommon. The coexistence of hepatocellular carcinoma (HCC) and renal cell carcinoma (RCC) is even rarer. We present a case of a 44-year-old male patient with a history of chronic hepatitis B and a right renal mass treated by radical nephrectomy. At the 2-month follow-up, a new lesion was detected in the left lobe of the liver. Postsurgery histologic evaluation with immunohistochemical study of both lesions confirmed the renal and hepatic lesions to be RCC and HCC, respectively.
The Long-Term Performance of Capital Expenditure from a Fundamental Perspective: Evidence from Indonesia

This study aims to identify the effect of capital expenditure on the long-term performance on companies listed on the Indonesia Stock Exchange (IDX). Fundamental measurements were used as the internal perspective of performance; This study also tries to fill the gap due to the lack of studies that discuss capital expenditure in Indonesia by providing empirical evidence regarding capital expenditure in the context of Indonesia's stock market. Capital expenditure is represented by the growth of fixed assets for the current period. The long-term performance utilizes earnings persistence and is measured using the regression of ROA and ROE for the past six years, and then the coefficients are determined using the lags of ROA and ROE in the three years after capital expenditure. The sample comprises 60 “big cap” companies listed on the IDX at the beginning of the sample period (in 2016) and for four years of the sampling period (2016–2019) with a total of 240 observations. The companies sampled should fulfill the criteria of having complete financial data for the six years before the sampling period. The hypothesis testing proves that capital expenditure impacts long-term performance, with no evidence to the contrary. Additional testing utilizing the control variables generated additional interesting results with important implications.
Weighted norm inequalities for fractional maximal operators--a Bellman function approach

We study classical weighted $L^p\to L^q$ inequalities for the fractional maximal operators on $\R^d$, proved originally by Muckenhoupt and Wheeden in the 70's. We establish a slightly stronger version of this inequality with the use of a novel extension of Bellman function method. More precisely, the estimate is deduced from the existence of a certain special function which enjoys appropriate majorization and concavity. From this result and an explicit version of the ``$A_{p-\varepsilon}$ theorem," derived also with Bellman functions, we obtain the sharp inequality of Lacey, Moen, P\'erez and Torres.
Radiation dynamics in X-ray binaries. III: Extremely compact objects

We calculate the spectral modifications which arise from the scattering of photons by accretion disks around nonmagnetic neutron stars. We find that extremely compact stars (which lie inside the marginally stable orbit) must exhibit a copious hard X-ray flux, and that the radiation field entirely dominates the dynamical behavior of disks around these objects. Based on these findings, we reinterpret the black hole candidates as extremely compact stars
Neurological Health Symptoms Associated with Pesticide Exposure among Farmers in Sharkia Governorate Districts

Background: Pesticides are widely utilized in agriculture, even pesticides have been outlawed in Western nations for owing to safety concerns remain extensively utilized in Egypt. Even though there are few researches on the neurological symptoms linked to pesticide exposure in Egypt. Recently, around 40% of the workforce in Egypt is worked in agriculture, with a risk of exposure to pesticides. Objective: This study's objective was to assess the neurological health effects of pesticide exposure among Egyptian farmers in the districts of Sharkia governorate. Patients and Methods: A case control study was held on 95 farmers and comparable non-exposed controls from different farms in four districts out of thirteen in Sharkia governorate were selected using multistage random sampling technique. Then, during the period between March and July 2020, interviews were conducted to gather demographic information, occupational history, and neurological health problems related to pesticide exposure. Blood samples underwent to acetyl-cholinesterase test to assess the extent of pesticide exposure. Results: Ninety-four percent of pesticide users claimed to have contact with organophosphate insecticides. The most common neurological symptom reported was a headache (69.5%), which was followed by poor attention (64.2%), a short memory (57.9%), and fatigue (55.8 percent). There was a statistically significant higher depression of AChE activity and its adjusted value (Q level) AChE/Hb level among farmers than their controls. Conclusion: A high prevalence of neurological symptoms was reported among Egyptian farmers using pesticides, which attributed to pesticide exposure causing severe depression in cholinesterase test. It`s recommended to conduct more informative researches to assess risk factors and improve awareness. Pesticide exposure, Farmers and acetyl-choline esterase activity.
Performance evaluation of lead vapor heat-pipe as a stimulated Raman converter for XeCl lasers

High power (6.6 W at 43 pps) stimulated Raman scattering at 459 nm was obtained by down shifting the radiation of a XeCl excimer laser in a lead vapor heat-pipe. Experiments were conducted with different buffer gas species. Photon conversion efficiency as high as 66 percent and energy slope efficiency of 53 percent obtained with Xe as the buffer gas at 1300°C. The apparatus was in daily use for a period of six months without maintenance.
Directional approach to spatial structure of solutions to the Navier–Stokes equations in the plane

We investigate a steady flow of incompressible fluid in the plane. The motion is governed by the Navier–Stokes equations with prescribed velocity u∞ at infinity. The main result shows the existence of unique solutions for arbitrary force, provided sufficient largeness of u∞. Furthermore a spatial structure of the solution is obtained in comparison with the Oseen flow. A key element of our new approach is based on a setting which treats the direction of the flow as the time direction. The analysis is done in the framework of the Fourier transform taken in one (perpendicular) direction and a special choice of function spaces which take into account the inhomogeneous character of the symbol of the Oseen system. From that point of view our technique can be used as an effective tool in examining spatial asymptotics of solutions to other systems modelled by elliptic equations.
Dynamical complexity and controlled operator K-theory

In this paper, we introduce a property of topological dynamical systems that we call finite dynamical complexity. For systems with this property, one can in principle compute the $K$-theory of the associated crossed product $C^*$-algebra by splitting it up into simpler pieces and using the methods of controlled $K$-theory. The main part of the paper illustrates this idea by giving a new proof of the Baum-Connes conjecture for actions with finite dynamical complexity. We have tried to keep the paper as self-contained as possible: we hope the main part will be accessible to someone with the equivalent of a first course in operator $K$-theory. In particular, we do not assume prior knowledge of controlled $K$-theory, and use a new and concrete model for the Baum-Connes conjecture with coefficients that requires no bivariant $K$-theory to set up.
A note on $n$-centralizer finite rings

Let $R$ be a finite ring and let $\Cent(R)$ denote the set of all distinct centralizers of $R$. $R$ is called an $n$-centralizer ring if $|Cent(R)| = n$. In this paper, we characterize $n$-centralizer finite rings for $n \leq 7$.
Lexical Density as Improvement Indicator in the Written Performance of EFL Majors

This study assesses lexical density in the written performance of a controlled sample of Saudi undergraduates majoring in English as a Foreign Language (EFL). It explores the relationship between lexical density and the quality of written performance by measuring lexical density in sample texts of learner's final exams. Linguistic content analysis was used on these texts to categorize terms and to find links between them. Each document’s functional and content terms were counted and divided by the total words in the text to compute lexical density. The study reveals that the lexical density in the written performance of Saudi EFL undergraduates is categorized as less dense than that of their higher-level peers, indicating an increase in lexical density as students are upgraded to higher levels of study. The lexical density varies according to a learner’s proficiency because the data obtained show differences between the lexical density scores of the two samples. The findings also suggest that the length of a text does not always imply that the content is lexically rich. The study provides evidence of the possibility of improving EFL learners’ reasoning performance when this performance is characterized by lexical density. The study urges that raising teachers’ awareness about lexical density and how it affects writing could also be a pedagogical implication of the current study.
Distinguishing Tournaments with Small Label Classes

A $d$-distinguishing vertex (arc) labeling of a digraph is a vertex (arc) labeling using $d$ labels that is not preserved by any nontrivial automorphism. Let $\rho(T)$ ($\rho'(T)$) be the minimum size of a label class in a 2-distinguishing vertex (arc) labeling of a tournament $T$. Gluck's Theorem implies that $\rho(T) \le \lfloor n/2 \rfloor$ for any tournament $T$ of order $n$. In this paper we construct a family of tournaments $\cal H$ such that $\rho(T) \ge \lfloor n/2 \rfloor$ for any order $n$ tournament in $\cal H$. Additionally, we prove that $\rho'(T) \le \lfloor 7n/36 \rfloor + 3$ for any tournament $T$ of order $n$ and $\rho'(T) \ge \lceil n/6 \rceil$ when $T \in {\cal H}$ and has order $n$. These results answer some open questions stated by Boutin.
Sources and variation of self-efficacy in cases of student teaching practicum

The purpose of the study was to determine student teachers’ personal self-efficacy beliefs and their views on what type of “sources” were behind self-efficacy in a lesson that they had just undertaken. Very little research-based understanding exists on how student teacher self-efficacy is formed, based on individual teaching situations. In this study, 10 student teachers’ interview data associated with the lesson, along with observation data with field notes, were collected. The interviews of four student teachers focusing on the lesson highlighted small (N=2) or somewhat larger (N=2) variations in levels of self-efficacy. Six student teachers had stable self-efficacy (N=6). The findings suggest that, in contrast to the expression of rather stable self-efficacy, a proportion of student teachers had feelings suggesting lower self-efficacy from time to time, although in general their thinking was dominated by average or high teaching efficacy.
Cauchy Tetrahedron Argument and the Proofs for the Existence of Stress Tensor, a Comprehensive Review, Challenges, and Improvements

In 1822, Cauchy presented the idea of traction vector that contains both the normal and tangential components of the internal surface forces per unit area and gave the tetrahedron argument to prove the existence of stress tensor. These great achievements form the main part of the foundation of continuum mechanics. For about two centuries, some versions of tetrahedron argument and a few other proofs of the existence of stress tensor are presented in every text on continuum mechanics, fluid mechanics, and the relevant subjects. In this article, we show the birth, importance, and location of these Cauchy's achievements, then by presenting the formal tetrahedron argument in detail, for the first time, we extract some fundamental challenges. These conceptual challenges are related to the result of applying the conservation of linear momentum to any mass element, the order of magnitude of the surface and volume terms, the definition of traction vectors on the surfaces that pass through the same point, the approximate processes in the derivation of stress tensor, and some others. In a comprehensive review, we present the different tetrahedron arguments and the proofs of the existence of stress tensor, discuss the challenges in each one, and classify them in two general approaches. In the first approach that is followed in most texts, the traction vectors do not exactly define on the surfaces that pass through the same point, so most of the challenges hold. But in the second approach, the traction vectors are defined on the surfaces that pass exactly through the same point, therefore some of the relevant challenges are removed. We also study the improved works of Hamel and Backus, and indicate that the original work of Backus removes most of the challenges. This article shows that the foundation of continuum mechanics is not a finished subject and there are still some fundamental challenges.
The Curie line in protoplanetary disks and the formation of Mercury-like planets

In laboratory experiments, we heated chondritic material up to 1400K in a hydrogen atmosphere. Moessbauer spectroscopy and magnetometry reveal that, at high temperatures, metallic iron forms from silicates. The transition temperature is about 1200K after 1 h of tempering, likely decreasing to about 1000K for longer tempering. This implies that in a region of high temperatures within protoplanetary disks, inward drifting solids will generally be a reservoir of metallic iron. Magnetic aggregation of iron-rich matter then occurs within the magnetic field of the disk. However, the Curie temperature of iron, 1041 K, is a rather sharp discriminator that separates the disk into a region of strong magnetic interactions of ferromagnetic particles and a region of weak paramagnetic properties. We call this position in the disk the Curie line. Magnetic aggregation will be turned on and off here. On the outer, ferromagnetic side of the Curie line, large clusters of iron-rich particles grow and might be prone to streaming instabilities. To the inside of the Curie line, these clusters dissolve, but that generates a large number density that might also be beneficial for planetesimal formation by gravitational instability. One way or the other, the Curie line may define a preferred region for the formation of iron-rich bodies.
Pegasus Project: Re-Questioning the Legality of the Cyber-Surveillance Mechanism

States have recently indulged in purchasing surveillance spyware such as Pegasus from big corporations such as the NSO Group to track the activities of its people to curb dissidents. Unfortunately, such incidences are not new in the international domain. Thus, it is imperative to analyze the legality of such spyware used by the states with the assistance of foreign corporates under the international framework. In view of the same, the paper while majorly focusing on the significance of right to privacy, traces the standing limitations in the legal mechanism and tries to propose a shared responsibility regime for states and surveillance companies indulging in human rights violations by drawing parallels with the ICoCA mechanism.
Summing Planar Diagrams by an Integrable Bootstrap II

In Reference [1] (henceforth referred to as I), we found some form factors of the renormalized field Φ, of the (1+ 1)dimensional principal chiral model in ’t Hooft’s planar lim t [2]. In particular, we obtained the oneand three-excita tion form factors (the two-excitation form factor is zero). These for m factors yield expressions for the correlation functions o f the renormalized field, for large separations. In this paper we extend our results to all form factors of Φ. We thereby obtain exact expressions for correlation functions. Thus the planar dia grams arecompletely resummed. Our technique is a combination of the form-factor axioms [3] and the 1/N-expansion of the exact S matrix [4], [5], [6]. A related development is the determination of the 1 /N-expansion of the twoand four-excitation form factors of c urrent operators, by A. Cortés Cubero [7]. We do not assume the reader is well-versed in form-factor lor e, but take for granted acquaintance with integrability and two-dimensional S-matrix theory. The bare field of the principal chiral model is a matrix U(x) ∈ SU(N), N ≥ 2, wherex0 and x1 are the time and space coordinates, respectively. The action is