Miracle-dz/UniFAR-FTUs huggingface dataset:
Fluid dynamic numerical simulation of a gas phase polymerization reactor

This article presents preliminary fluid dynamic simulation results of ethylene polymerization dense fluidized bed using the two‐phase flow numerical code ESTET‐ASTRID developed by Electricité de France for CFB boilers and based on the two‐fluid modelling approach. The continuous phase consists of gas and the dispersed phase consists of catalyst particles. The particle fluctuating motion is modelled using two‐separate transport equations, on the particle kinetic energy and the fluid–particle covariance, developed in the frame of kinetic theory of granular medium accounting for particle–particle and fluid–particle interactions. Time‐dependent 2D and 3D simulations have been performed for industrial and pilot reactor operating conditions. The numerical predictions are in good qualitative agreement with the observed behaviour in terms of bed height, pressure drop and mean flow organization, such as the down falling of the PE particle layer along the walls. Moreover, these simulations help to provide information about instantaneous and time‐averaged solid concentration and velocity fields. Characteristic mechanisms and influence of model closure assumptions on flow predictions are also investigated. Finally, such numerical simulations look very powerful, when validated on exhaustive data collection, to improve design and performance of industrial facilities and to provide insight into the complex physical mechanisms involved. Copyright © 2003 John Wiley & Sons, Ltd.
Functional Compounds of Cold-Pressed Pomegranate Seed Oil: Fatty Acids and Phytosterols Profile as Quality Biomarkers for Origin Discrimination

Cold-pressed pomegranate seed oil (PSO) is a product of the extraction of non-edible pomegranate seeds. Its unique chemical composition in terms of both polyunsaturated fatty acids, especially punicic acid (PA), and secondary metabolites, such as phytosterols, tocopherols and phenols, make it an interesting functional ingredient for food enrichment. It is not clear if the biomarkers profile of PSO depends to factors connected to the geographical origin of seeds. This work presents a statistical comparative analysis, concerning biomolecules composition and geographical origin of 32 commercial cold-pressed PSOs, performed by principal component analysis. The study discriminates between Turkish and Italian PSOs, on the base of the fatty acid profile and phytosterols, and not on the tocopherols and phenols. These results confirmed PA as the main characteristic biomarker of oil genuineness and, for the first time, disclosed a statistically relevant variability of phytosterols, which can be proposed as quality biomarkers for discrimination of geographical origins.
Prioritization Based Task Offloading in UAV-Assisted Edge Networks

Under demanding operational conditions such as traffic surges, coverage issues, and low latency requirements, terrestrial networks may become inadequate to provide the expected service levels to users and applications. Moreover, when natural disasters or physical calamities occur, the existing network infrastructure may collapse, leading to formidable challenges for emergency communications in the area served. In order to provide wireless connectivity as well as facilitate a capacity boost under transient high service load situations, a substitute or auxiliary fast-deployable network is needed. Unmanned Aerial Vehicle (UAV) networks are well suited for such needs thanks to their high mobility and flexibility. In this work, we consider an edge network consisting of UAVs equipped with wireless access points. These software-defined network nodes serve a latency-sensitive workload of mobile users in an edge-to-cloud continuum setting. We investigate prioritization-based task offloading to support prioritized services in this on-demand aerial network. To serve this end, we construct an offloading management optimization model to minimize the overall penalty due to priority-weighted delay against task deadlines. Since the defined assignment problem is NP-hard, we also propose three heuristic algorithms as well as a branch and bound style quasi-optimal task offloading algorithm and investigate how the system performs under different operating conditions by conducting simulation-based experiments. Moreover, we made an open-source contribution to Mininet-WiFi to have independent Wi-Fi mediums, which were compulsory for simultaneous packet transfers on different Wi-Fi mediums.
Order Reduction of Large-Scale Linear Dynamic Systems Using Balanced Truncation with Modified Cauer Continued Fraction

This article discusses a new technique to reduce the order of high-dimensional, continuous, linear time-invariant dynamic systems. The proposed approach utilizes the merits of the balanced truncation method, and modified Cauer continued fraction expansion. The reduced model denominator was retrieved via the concept of Lyapunov balancing, and state truncation and numerator coefficients were obtained by using a modified Cauer continued fraction. The proposed technique circumvents the steady-state gain discrepancy and steady-state error mismatch of the conventional balanced truncation method, and the instability issue of continued fraction expansion. The proposed method assures steady-state gain approximation, few moments, Markov parameters, stability, and other essential control features of a high-order system. The efficacy and applicability of the proposed technique are demonstrated using some typical test systems adopted from the literature. This method gives improved performance indices like minimum H∞ norm, H2 norm, a minimum ISE (integral squared error), IAE (integral absolute error), and retains approximately the full IRE (impulse response energy) of the existing system in the reduced model. The simulation findings of the proposed technique are compared with other current model reduction methods in recent literature using MATLAB.
On the Problem of Permissible Covariance and Variogram Models

The covariance and variogram models (ordinary or generalized) are important statistical tools used in various estimation and simulation techniques which have been recently applied to diverse hydrologic problems. For example, the efficacy of kriging, a method for interpolating, filtering, or averaging spatial phenomena, depends, to a large extent, on the covariance or variogram model chosen. The aim of this article is to provide the users of these techniques with convenient criteria that may help them to judge whether a function which arises in a particular problem, and is not included among the known covariance or variogram models, is permissible as such a model. This is done by investigating the properties of the candidate model in both the space and frequency domains. In the present article this investigation covers stationary random functions as well as intrinsic random functions (i.e., nonstationary functions for which increments of some order are stationary). Then, based on the theoretical results obtained, a procedure is outlined and successfully applied to a number of candidate models. In order to give to this procedure a more practical context, we employ “stereological” equations that essentially transfer the investigations to one-dimensional space, together with approximations in terms of polygonal functions and Fourier-Bessel series expansions. There are many benefits and applications of such a procedure. Polygonal models can be fit arbitrarily closely to the data. Also, the approximation of a particular model in the frequency domain by a Fourier-Bessel series expansion can be very effective. This is shown by theory and by example.
The ΩM-ΩΛ Dependence of the Apparent Cluster Ω

The Canadian Network for Observational Cosmology cluster data are used to constrain the ΩM-ΩΛ pair to the region ΩM ≃ 0.24e± 0.3(1-0.4ΩΛ) for 0≤ΩΛ ≤ 1. The constraint is based on estimating the apparent mass density of the universe, Ωe(z), as the product of cluster mass-to-light ratios, M/L, with the field luminosity density at the same redshift. The luminosity density contains a volume element, which for measurements at z > 0 causes Ωe(z) to depend on both the density parameter ΩM and the cosmological constant, ΩΛ. The ΩΛ-dependence of the Ωe(z) measurement is about 25% less than the volume-redshift relation but about 50% greater than the luminosity-redshift relation. Most usefully this constraint is approximately orthogonal to the luminosity-redshift relation in the ΩM-ΩΛ plane. The practical application to measuring cosmological parameters has the considerable benefit that all quantities are used in a differential sense, so that common selection effects and galaxy evolution effects will cancel. The residual differential galaxy evolution between field, and the clustered galaxies can be estimated from the sample data. The inferred ΩM has an inverse correlation with ΩΛ, giving a constraint complementary to both the cosmic microwave background and the supernovae distances. Monte Carlo simulations, calibrated with observational data, show that 100 clusters spread over the 0-1 redshift range, each having M/L values of about 25% accuracy, will measure ΩΛ to about 7% statistical error.
Substitutional and interstitial oxygen in wurtzite GaN

First-principles theoretical results are presented for substitutional and interstitial carbon in wurtzite GaN. Carbon is found to be a shallow acceptor when substituted for nitrogen (CN) and a shallow donor when substituted for gallium (CGa). Interstitial carbon (CI) is found to assume different configurations depending on the Fermi level: A site at the center of the c-axis channel is favored when the Fermi level is below 0.9 eV (relative to the valence band maximum) and a split-interstitial configuration is favored otherwise. Both configurations produce partly filled energy levels near the middle of the gap, and CI should therefore exhibit deep donor behavior in p-type GaN and deep acceptor behavior in n-type GaN. Formation energies for CN, CGa, and CI are similar, making it likely that CN acceptors will be compensated by other carbon species. CGa is predicted to be the primary compensating species when growth occurs under N-rich conditions while channel CI is predicted to be the primary compensating spe.
Congenital Pulmonary Airway Malformations With a Reconsideration and Current Perspective on the Stocker Classification

Congenital cystic pulmonary lesions (CCPLs) are represented by the following entities: congenital pulmonary airway malformation (CPAM), formerly congenital cystic adenomatoid malformation, extra- and intralobar sequestration (EIS), congenital lobar emphysema (overexpansion), and bronchogenic cyst. The developmental model of CPAM histogenesis by Stocker proposed perturbations designated as CPAM type 0 to type 4 without known or specific pathogenetic mechanisms along the airway from the bronchus to the alveolus. This review highlights mutational events either at the somatic level in KRAS (CPAM types 1 and possibly 3) or germline variants in congenital acinar dysplasia, formerly CPAM type 0, and pleuropulmonary blastoma (PPB), type I, formerly CPAM type 4. The potential for overt malignant progression exists in the case of PPB type I and CPAM type 1 in some cases to well-differentiated mucinous adenocarcinoma. On the other hand, CPAM type 2 is an acquired lesion resulting from interruption in lung development secondary to bronchial atresia. The latter is also regarded as the etiology of EIS whose pathologic features are similar, if not identical, to CPAM type 2. These observations have provided important insights into the pathogenetic mechanisms in the development of the CPAMs since the Stocker classification.
MAGNETIC PROPERTIES OF S-SHAPED SPLIT-RING RESONATORS

We present a theoretical analysis of the radiation of an S-shaped split ring resonator (S-SRR) for the realization of a metamaterial exhibiting left-handed properties. It is shown that the structure is resonant due to its internal capacitances and inductances, which can be adjusted such that the electric plasma frequency and magnetic plasma frequency, both due to the S-SRR only, appear within the same frequency band. Using the same idea, we also present some extended S-shaped split-ring resonator structures with improved performance.
Can Fintech Alleviate the Financing Constraints of Enterprises?—Evidence from the Chinese Securities Market

Whether Fintech enabled by big data technology can improve the efficiency of credit allocation and how it would do has always been the focus in the capital market, especially the intermediary mechanism, which has not yet been convincingly explained. This paper empirically tests the logical relationship and micro mechanism between Fintech and the corporate financing constraint dilemma by using the data of China’s A-share non-financial listed companies from 2011 to 2018. The research found that Fintech has a significant mitigation effect on corporate financing constraints, and the coverage capability of Fintech has a stronger mitigation effect compared to the depth of use. Mechanism research shows that the “technology enabling” role of Fintech can alleviate the financing constraints of enterprises by reducing the degree of information asymmetry between capital supply and demand sides and reducing financing costs. Heterogeneity research shows that the mitigation effect of Fintech on corporate financing constraints is more significant in enterprises with private property, non-main board listing, senior executives with high financial literacy, and enterprises with strong competitive positions in the industry. Further research shows that, in order to identify the impact of Fintech on corporate financing types under an environment without internal control defects, Fintech enables enterprises facing financing constraints to obtain more commercial credit and bank loans; at a time when it is difficult to obtain bank loans, commercial credit has become an alternative financing method of bank loans, promoting the transfer of credit resources from traditional mortgage guarantees to enterprise commercial credit. This study provides a perspective for the research on how Fintech alleviates corporate financing constraints, and it reveals the characteristics of digital empowerment in the development of China’s capital market, providing a theoretical basis and evidence supporting the formulation of relevant policies.
Wind variability of B supergiants. IV. A survey of IUE time-series data of 11 B0 to B3 stars

We present the most suitable data sets available in the International Ultraviolet Explorer (IUE) archive for the study of time-dependent stellar winds in early B supergiants. The UV line prole variability in 11 B0 to B3 stars is analysed, compared and discussed, based on 16 separate data sets comprising over 600 homogeneously reduced high-resolution spectrograms. The targets include \normal" stars with moderate rotation rates and examples of rapid rotators. A gallery of grey-scale images (dynamic spectra) is presented, which demonstrates the richness and range of wind variability and highlights dierent structures in the winds of these stars. This work emphasises the suitability of B supergiants for wind studies, under-pinned by the fact that they exhibit unsaturated wind lines for a wide range of ionization. The wind activity of B supergiants is substantial and has highly varied characteristics. The variability evident in individual stars is classied and described in terms of discrete absorption components, spontaneous absorption, bowed structures, recurrence, and ionization variability and stratication. Similar structures can occur in stars of dierent fundamental parameters, but also dierent structures may occur in the same star at a given epoch. We discuss the physical phenomena that may be associated with the spectral signatures. The diversity of wind patterns evident likely reflects the role of stellar rotation and viewing angle in determining the observational characteristics of azimuthally extended structure rooted at the stellar surface. In addition, SEI line-synthesis modelling of the UV wind lines is used to provide further information about the state of the winds in our program stars. Typically the range, implied by the line prole variability, in the product of mass-loss rate and ion fraction ( _ Mq i) is a factor of 1.5, when integrated between 0.2 and 0.9 v1 ;i t can however be several times larger over localised velocity regions. At a given eective temperature the mean relative ion ratios can dier by a factor of 5. The general excess in predicted (forward-scattered) emission in the low velocity regime is discussed in terms of structured outflows. Mean ion fractions are estimated over the B0 to B1 spectral classes, and trends in the ionic ratios as a function of wind velocity are described. The low values obtained for the ion fractions of UV resonance lines may reflect the role of clumping in the wind.
Semen Quality of the First and Second Ejaculates Collected from Breeding Inactive Stallions after Cooling and Freezing

Simple Summary To determine the semen quality after cooling and freezing, the first and second ejaculates of the season were collected 1 h apart. After collection, the gel-free semen volume, concentration, total number of sperm, and sperm morphology were determined. An aliquot of the ejaculate was extended and cooled for 48 h; a second aliquot was processed, centrifuged, and then cooled for 48 h; and a third aliquot was processed and then frozen. The sperm parameters were assessed pre-(0 h), 24 h, and 48 h post-cooling and before and after freezing. The first and second ejaculates of the season collected 1 h apart varied in quantity but not in quality. Centrifugation prevented a reduction in the sperm quality after cooling. The semen freezing did not vary between the first and second ejaculates. Abstract This study aimed to assess the semen quality after the cooling and freezing of the first and second ejaculates of the season, which were collected 1 h apart. After collection (n = 40 ejaculates), the gel-free semen volume, concentration, total number of sperm, and sperm morphology were determined. An aliquot of each ejaculate was extended and cooled for 48 h; a second aliquot was cushion-centrifuged and cooled for 48 h; and a third aliquot was processed and then frozen. The total motility (TM) and progressive motility (PM), plasma membrane integrity (PMI), and high mitochondrial membrane potential (HMMP) were assessed pre-(0 h), 24 h, and 48 h post-cooling and before and after freezing. The second ejaculate had a lower gel-free semen volume (p = 0.026). The sperm concentration was greater in the first than in the second ejaculate (p < 0.001). The sperm morphology was similar between the ejaculates (p > 0.05). Cushion-centrifugation prevented a reduction in the TM, PM, and PMI over time (p < 0.05). The TM, PM, and PMI decreased after freezing but not between the ejaculates (p > 0.05). The first and second ejaculates of the season, which were collected 1 h apart, varied in quantity but not in quality after cooling and freezing.
Lower bounds on the stable range of polynomial rings.

THEOREM A. Let K be any commutative ring. For every integer n^l let K(n) = K[ZU •••, Zn] be the polynomial ring over K in indeterminates Zly •••, Zn. Then ( 1 ) The stable range of K(ί) is at least 2 ( 2 ) The stable range of K(n) is at least [n/2] + 1 if n ^ 2. ( 3 ) (Vasershtein, [6, Theorem 8]). If there is a ring homomorphism from K to a sub field of real numbers, then the stable range of K{n) is at least n + l
The Impact of Artificial Intelligence on Workers' Skills: Upskilling and Reskilling in Organisations

Aim/Purpose: This paper aims to investigate the recent developments in research and practice on the transformation of professional skills by artificial intelligence (AI) and to identify solutions to the challenges that arise. Background: The implementation of AI in various organisational sectors has the potential to automate tasks that are currently performed by humans or to reduce cognitive workload. While this can lead to increased productivity and efficiency, these rapid changes have significant implications for organisations and workers, as AI can also be perceived as leading to job losses. Successfully adapting to this transformation will lead companies and institutions to new working and organisational models, which requires implementing measures and strategies to upskill or reskill workers. Organisations, therefore, face considerable challenges such as guiding employees towards the change process, dealing with the cost of training, and ensuring fairness and inclusion posed by age, gender, and cultural diversity. Methodology: A narrative review has been conducted to analyse research and practice on the impact of AI on human skills in organisations. Contribution: This work contributes to the body of knowledge by examining recent trends in research and practice on how AI will transform professional skills and workplaces, highlighting the crucial role played by transversal skills and identifying strategies that can support organisations and guide workers toward the upskilling and reskilling challenges. Findings: This work found that introducing AI in organisations combines many organisational strategies simultaneously. First, it is critical to map the transversal skills needed by workers to mitigate the current skills gap within the workplace. Secondly, organisations can help workers identify the skills required for AI adoption, improve current skills, and develop new skills. In addition, the findings show that companies need to implement processes to support workers by providing ad hoc training and development opportunities to ensure that workers’ attitudes and mental models towards AI are open and ready for the changing labour market and its related challenges. Recommendation for Researchers: AI is a complex and multifaceted field that encompasses a wide range of disciplines, including computer science, mathematics, engineering, and behavioural and social sciences. Researchers should take a transdisciplinary approach to enable the integration of knowledge and perspectives from different fields that are essential to understanding the full range of implications and applications of AI. Future Research: Further research is needed to understand the impact of AI on human skills and the role of soft skills in the adoption of AI in organisations. Future studies should also consider the challenges presented by Industry 5.0, which is likely to involve the integration of new technologies and automation on an even greater scale.