Miracle-dz/UniFAR-FTUs huggingface dataset:
Stable carbon and oxygen isotope geochemistry as provenance indicator for the picture stones on Gotland (Sweden)

ABSTRACT The picture stones from Gotland are one of the most famous and exceptional groups of monuments known from Swedish Prehistory. These carved memorial stones and their extraordinarily rich imagery are a unique source for the study of Late Iron and Viking Age culture and in particular Scandinavian pre-Christian religions. The Gotlandic picture stones are mainly made from the thickly layered limestones surrounding the reefs and bioherms of Gotland’s carbonate platform from the middle part of the Silurian (latest Llandovery to Ludlow, Telychian – Ludfordian). However, the exact origins of the picture stones’ raw materials on Gotland have remained undetermined. In this paper, we investigate the geological origin of the raw material by isotope geochemistry. Whereas the oxygen (δ18O) and strontium isotope ratio (87Sr/86Sr) were strongly altered by diagenesis the carbon isotope ratio (δ13C) is quite stable. Because the different geological units on Gotland show specific isotope signatures, the δ13C values from picture stones can be used to assign them to the respective geological unit, and thus to the source area of the raw material. This also allows for an estimation of transport distance minima between the raw material source area and the find place of each sampled picture stone. Most of the picture stones seem to be produced from local material with short transport distances, less than 10 km and only a few were transported at a far distance exceeding 10 km. In summary, the transport distance was dependent mostly on the local availability of picture-stone-suitable rocks.
Flow with a free surface in a Hele-Shaw cell: experiments and theory

ABSTRACT The solution of Boussinesq's equation that describes the free surface of water flowing steadily through a dam on an impervious bottom can be generalized to quasi steady propagation of water into an initially dry dam. If the water level in the reservoir rises with constant speed from zero, a closed solution of Boussinesq nonlinear equation can be found since the problem lacks characteristic length. The solution shows that the advance rate of the saturated zone is constant. Experiments in a vertical Hele-Shaw cell, resting on an impervious bottom and connected with a reservoir filled with glycerine have been made. The results show that if the level in the reservoir rises linearly with time from zero, the horizontal advancement of the glycerine increases linearly with time.
A posteriori error estimator based on derivative recovery for the discontinuous Galerkin method for nonlinear hyperbolic conservation laws on Cartesian grids

In this article, we develop and analyze a new recovery‐based a posteriori error estimator for the discontinuous Galerkin (DG) method for nonlinear hyperbolic conservation laws on Cartesian grids, when the upwind flux is used. We prove, under some suitable initial and boundary discretizations, that the L 2 ‐norm of the solution is of order p + 1 , when tensor product polynomials of degree at most p are used. We further propose a very simple derivative recovery formula which gives a superconvergent approximation to the directional derivative. The order of convergence is showed to be p + 1 / 2 . We use our derivative recovery result to develop a robust recovery‐type a posteriori error estimator for the directional derivative approximation which is based on an enhanced recovery technique. The proposed error estimators of the recovery‐type are easy to implement, computationally simple, asymptotically exact, and are useful in adaptive computations. Finally, we show that the proposed recovery‐type a posteriori error estimates, at a fixed time, converge to the true errors in the L 2 ‐norm under mesh refinement. The order of convergence is proved to be p + 1 / 2 . Our theoretical results are valid for piecewise polynomials of degree p ≥ 1 and under the condition that each component, | f i ′ ( u ) | , i = 1 , 2 , of the flux function possesses a uniform positive lower bound. Several numerical examples are provided to support our theoretical results and to show the effectiveness of our recovery‐based a posteriori error estimator. © 2016 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 33: 1224–1265, 2017
A New Multistep Technique Based on the Nonuniform Rational Basis Spline Curves for Nonlinear Transient Heat Transfer Analysis of Functionally Graded Truncated Cone

ABSTRACT A novel multistep method based on the nonuniform rational basis spline curves is developed for the solution of a system of nonlinear differential equations. Efficiency of the presented method in terms of convergence and accuracy is demonstrated through the two-dimensional nonlinear transient heat transfer analysis of multilayered functionally graded truncated cone subjected to an internal thermal load with radiative–convective boundary condition at outer surface. In order to discretize the governing equations in the spatial domain, a layerwise-differential quadrature method is implemented. This transforms the partial differential equations into a system of nonlinear ordinary differential equations in the temporal domain, which is then solved using the presented technique. Comparative studies between predictions of the presented multistep technique and various existing numerical methods demonstrate superior computational efficiency of the method with low computational cost. High efficiency of this method indicated that the presented multistep approach can be successfully employed in various nonlinear problems. Finally, the effects of different parameters on the transient temperature of the truncated cone are studied. It is expected that the presented multistep method will be applied on various practical engineering problems in future studies.
On the Pareto Compliance of the Averaged Hausdorff Distance as a Performance Indicator

The averaged Hausdorff distance ∆p is an inframetric, recently introduced in evolutionary multiobjective optimization (EMO) as a tool to measure the optimality of finite size approximations to the Pareto front associated to a multiobjective optimization problem (MOP). Tools of this kind are called performance indicators, and their quality depends on the useful criteria they provide to evaluate the suitability of different candidate solutions to a given MOP. We present here a purely theoretical study of the compliance of the ∆p -indicator to the notion of Pareto optimality. Since ∆p is defined in terms of a modified version of other well- known indicators, namely the generational distance GDp , and the inverted generational distance IGDp , specific criteria for the Pareto compliance of each one of them is discussed in detail. In doing so, we review some previously available knowledge on the behavior of these indicators, correcting inaccuracies found in the literature, and establish new and more general results, including detailed proofs and examples of illustrative situations.
Bifurcating Mach Shock Reflections with Application to Detonation Structure

Numerical simulations of Mach shock reflections have shown that the Mach stem can bifurcate as a result of the slip line jetting forward. Numerical simulations were conducted in this study which determined that these bifurcations occur when the Mach number is high, the ramp angle is high, and specific heat ratio is low. It was clarified that the bifurcation is a result of a sufficiently large velocity difference across the slip line which drives the jet. This bifurcation phenomenon has also been observed after triple point collisions in detonation simulations. A triple point reflection was modelled as an inert shock reflecting off a wedge, and the accuracy of the model at early times after reflection indicates that bifurcations in detonations are a result of the shock reflection process. Further investigations revealed that bifurcations likely contribute to the irregular structure observed in certain detonations.
Rate-Adaptive Neural Network for Image Compressive Sensing

Deep learning-based image compressive sensing (CS) methods have achieved great success in the past few years. However, most of them are content-independent, with a spatially uniform sampling rate allocation for the entire image. Such practises may potentially degrade the performance of image CS with block-based sampling, since the content of different blocks in an image is different. In this article, we propose a novel rate-adaptive image CS neural network (dubbed RACSNet) to achieve adaptive sampling rate allocation based on the content characteristics of the image with a single model. Specifically, a measurement domain-based reconstruction distortion is first used to guide the sampling rate allocation for different blocks in an image without access to the ground truth image. Then, a step-wise training strategy is designed to train a reusable sampling matrix, which is capable of sampling image blocks to generate the compressed measurements under arbitrary sampling rates. Subsequently, a pyramid-shaped initial reconstruction sub-network and a hierarchical deep reconstruction sub-network that fuse the measurement information of different scales are put forward to reconstruct image blocks from the compressed measurements. Finally, a reconstruction distortion map and an improved loss function are developed to eliminate the blocking artifacts and further enhance the CS reconstruction. Experimental results on both objective metrics and subjective visual qualities show that the proposed RACSNet achieves significant improvements over the state-of-the-art methods.
Active Cellulose Acetate/Chitosan Composite Films Prepared Using Solution Blow Spinning: Structure and Electrokinetic Properties

Cellulose acetate (CA), a very promising derivative of cellulose, has come into the focus of research due to its highly desired good film-forming ability for food packaging applications. Frequently, this derivative is used in combination with other compounds (polymers, nanoparticles) in order to obtain active materials. Here, we report the preparation of thin films made of cellulose acetate loaded with chitosan (CS) using the solution blow spinning (SBS) method. Films are prepared by SBS processing of the polymers mixture solution, considering the following variables: (i) the concentration of cellulose acetate and chitosan in the solution and (ii) the solvent system consisting of acetic or formic acid. The prepared materials are characterized in terms of physical properties, roughness (optical profilometer), porosity, wettability (contact angle measurements), chemical structure (Fourier transform infrared spectrometry), and electrokinetic properties (zeta potential). SBS enables the preparation of CA/CS films with high water vapor permeability, high porosity, and also higher water contact angle compared with pure CA films. The electrokinetic properties of composites are influenced by the inclusion of chitosan, which causes a shift of the isoelectric point (IEP) towards higher pH values, but the magnitude of the shift is not in correlation with chitosan concentration. Adsorption kinetic studies using bovine serum albumin (BSA) as a model protein reveal that chitosan modified cellulose acetate films manifest low affinity towards proteins that suggests prevention of biofilm formation on its surface.
The Prediction of Residual Electrical Life in Alternating Current Circuit Breakers Based on Savitzky-Golay-Long Short-Term

In order to improve the accuracy of predicting the remaining electrical life of AC circuit breakers, ensure the safe operation of electrical equipment, and reduce economic losses caused by equipment failures, this paper studies a method based on the Savitzky–Golay convolution smoothing long short-term memory neural network for predicting the electrical life of AC circuit breakers. First, a full lifespan test is conducted to obtain degradation data throughout the entire life cycle of the AC circuit breaker, from which feature parameters that effectively reflect its operational state are extracted. Next, principal component analysis and the maximum information coefficient are used to remove redundancy in the feature parameters and choose the best subset of features. Subsequently, the Savitzky–Golay convolutional smoothing algorithm is employed to smooth the feature sequence, reducing the impact of noise and outliers on the feature sequence while preserving its main trends. Then, a secondary feature extraction is performed on the smoothed feature subset to obtain the optimal secondary feature subset. Finally, the remaining electrical lifespan of the AC circuit breaker is treated as a long-term sequence problem and the long short-term memory neural network method is used for precise time-series forecasting. The proposed model outperforms backpropagation neural networks and the gate recurrent unit in terms of prediction precision, achieving an impressive 97.4% accuracy. This demonstrates the feasibility of using time-series forecasting for predicting the residual electrical lifespan of electrical equipment and provides a reference for optimizing the method of predicting remaining electrical life.
A Comprehensive Analysis of Swift/XRT Data: IV. Single Power-Law Decaying XRT lightcurves and Implications for the Unified Origin of the X-rays

By systematically analyzing the Swift/XRT lightcurves detected before 2008 October, we find 17 lightcurves that monotonously decay as a single power law (SPL) with an index of 1 ∼ 1.7 from tens (or hundreds) of seconds to ∼ 10 seconds post the GRB trigger. They are apparently different from the canonical lightcurves that are characterized by a shallow-to-normal decay transition. We compare the distributions of the observables of the prompt gamma-rays in the Swift/BAT band for the two groups of GRBs, but no statistical difference is found. The spectral characteristics of the X-rays, including the integrated Xray spectral index, the column density of neutral hydrogen (NH) of the host galaxies, and the spectral evolution feature, between the two groups of GRBs are also consistent with each other. Interestingly, the SPL XRT lightcurves in the burst frame gradually merge into a conflux, and their luminosities at 10 seconds are normally distributed at log L/ergs s = 45.5 ± 0.7. For the GRBs with canonical (shallow-to-normal) lightcurves, the normal decay segment has the similar feature. These results likely suggest that both the prompt gammarays and the X-rays for the two groups of GRBs may share the similar physical origins, and the apparent difference between the XRT lightcurves of two groups of GRBs may not be intrinsic. If the shallow decay is due to energy injection into the fireball, this suggests that the total energy budget after injection for both types of GRBs is similar. More intriguingly, the picture is consistent with the scenario that the apparent shallow-to-normal behavior is an artifact because of the improper choice of the zero time point (T0), as suggested by Yamazaki. To Department of Physics, Guangxi University, Nanning 530004, China;lew@gxu.edu. cn Department of Physics and Astronomy, University of Nevada, Las Vegas, NV 89154; zhang@physics.unlv. edu
A Narrative Review Discussing the Obstetric Repercussions Due to Alterations of Personalized Bacterial Sites Developed within the Vagina, Cervix, and Endometrium

Background: The reproductive tract microbiota that evolved as an integrative component has been studied intensively in the last decade. As a result, novel research, clinical opportunities, and perspectives have been derived following the close investigation of this microecological environment. This has paved the way for an update to and improvement of the management strategies and therapeutic approaches. However, obscurities, contradictions, and controversies arise regarding the ascension route from the vagina to the endometrium via the cervix, with finality in adverse obstetric outcomes. Methods: Starting from these considerations, we aimed to gather all existing data and information from four major academic databases (PubMed, ISI Web of Knowledge, Scopus, and ScienceDirect) published in the last 13 years (2010–2023) using a controlled vocabulary and dedicated terminology to enhance the coverage, identification, and sorting of potentially eligible studies. Results: Despite the high number of returned entries (n = 804), only a slight percentage (2.73%) of all manuscripts were deemed eligible following two rounds of evaluation. Cumulatively, a low level of Lactobacillus spp. and of other core microbiota members is mandatory, with a possible eubiosis-to-dysbiosis transition leading to an impairment of metabolic and endocrine network homeostasis. This transposes into a change in the pro-inflammatory landscape and activation of signaling pathways due to activity exerted by the bacterial lipopolysaccharides (LPSs)/endotoxins that further reflect a high risk of miscarriage in various stages. While the presence of some pathogenic entities may be suggestive of an adverse obstetric predisposition, there are still pros and cons of the role of specific strains, as only the vagina and cervix have been targeted as opposed to the endometrium, which recently started to be viewed as the key player in the vagina–cervix–endometrium route. Consequently, based on an individual’s profile, diet, and regime, antibiotics and probiotics might be practical or not. Conclusions: Resident bacteria have a dual facet and are beneficial for women’s health, but, at the same time, relaying on the abundance, richness, and evenness that are definitory indexes standing as intermediaries of a miscarriage.
Development, physicochemical characterization and in-vitro biocompatibility study of dromedary camel dentine derived hydroxyapatite for bone repair

This study aimed to produce hydroxyapatite from the dentine portion of camel teeth using a defatting and deproteinizing procedure and characterize its physicochemical and biocompatibility properties. Biowaste such as waste camel teeth is a valuable source of hydroxyapatite, the main inorganic constituent of human bone and teeth which is frequently used as bone grafts in the biomedical field. Fourier Transform infrared (FTIR), and micro-Raman spectroscopy confirmed the functional groups as-sociated with hydroxyapatite. X-ray diffraction (XRD) studies showed camel dentine-derived hydroxyapatite (CDHA) corresponded with hydroxyapatite spectra. Scanning electron micros-copy (SEM) demonstrated the presence of dentinal tubules measuring from 1.69–2.91 µm. The inorganic phases of CDHA were primarily constituted of calcium and phosphorus, with trace levels of sodium, magnesium, potassium, and strontium, according to energy dispersive X-ray analysis (EDX) and inductively coupled plasma mass spectrometry (ICP-MS). After 28 days of incubation in simulated body fluid (SBF), the pH of the CDHA scaffold elevated to 9.2. in-vitro biocompatibility studies showed that the CDHA enabled Saos-2 cells to proliferate and express the bone marker osteonectin after 14 days of culture. For applications such as bone augmentation and filling bone gaps, CDHA offers a promising material. However, to evaluate the clinical feasibility of the CDHA, further in-vivo studies are required.
Inferences Based on Robust Regression Estimators When There Is Multicolinearity

The paper deals with the goal of testing hypotheses about the slope parameters of a linear regression model when there is multicolinearity. A heteroscedastic method was recently derived based on a ridge estimator, but it does not guard against the deleterious impact of outliers. Several robust analogs of the ridge estimator have been proposed that might deal with this concern. The goal here is to find a robust method that performs reasonably well in simulations.
Melt pool size of optical glass irradiated by semiconductor laser

ABSTRACT Using a continuous laser to soften glass locally is a novel way of selective glass forming. Due to gaussian distribution of laser power density, a temperature gradient will be generated on glass treated with localized irradiation by laser, which brings about the coexistence of a glass state and a viscoelastic state. This situation creates a bulge on the surface of the softened area. Based on this phenomenon, we propose a measurement approach and a calculation model for the softening zone width of glass irradiated locally by laser and verify the calculation model through simulations and experiments. The maximum temperature deviation of the proposed temperature field prediction model is 4.7°C, while the minimum deviation is 0.53°C; making the deviation between the calculation model of the softening zone width and the experimental measurement result less than 0.319%.
Probing the optical characteristics of MoS2 under external electrical fields using polarized Raman spectroscopy

Raman spectroscopy effectively revealed a strain-induced electronic structure change during polarization-dependent studies on molybdenum disulfide (MoS2). Initially, we used a polarized Raman system to obtain the polarization-dependent Raman spectra of single-, bi-, and tri-layer MoS2 and analyzed their vibration modes. We determined that the in-plane () mode of vibration was double-degenerate whereas the out-of-plane (A1g) mode of vibration was not. We also observed the mode to be independent of polarization, and the A1g mode to be quadratically dependent on the cosine of the polarization angle. The experimental data agreed strongly with the theoretical models. We present the Raman spectra collected with applied top gate voltages and operational frequencies for an MoS2 transistor. The Raman signal intensities, peak positions, and linewidths of two active modes were calculated under different applied top gate voltages and operational frequencies. The broadening of linewidth for the out-of-plane mode was a result of the strengthening of electron–phonon coupling with increasing gate voltage. Owing to the electric potential across the metal-MoS2 interface, a dramatic frequency shift can be observed. For the AC operational mode, the Raman signals can be regarded as constant in the proper operational frequency region.
Crack Tip Flipping Under Mode I/III Tearing

Summary Crack tip ﬂipping, where the fracture surface alternates from side to side in 45 ◦ shear bands, seems to be an overlooked propagation mode in Mode I sheet tearing often disregarded as “transitional” or tied to randomness in the material. In fact, such observations rarely make it to the literature. However, crack tip ﬂipping is a true propagation mode, but unlike those already established: i) it never settles in a steady-state as the near tip stress/strain ﬁeld continuously change, and ii) the mechanism governing failure evolves behind the leading crack tip. Recent research has revealed new insight into this intriguing behavior of a crack propagating by the void nucleation and growth mechanism, and the work presented compiles both published and unpublished experimental and numerical ﬁndings. E.g. in a recent attempt to gain control of the ﬂipping crack a slight Mode III was imposed with interesting results.