bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermo-mechanical and opto-electrical study of Cr-doped-ZnO-based polyvinyl chloride nanocomposites
Authors: Ahmed Hanaa. M. , Abd El-Fattah Zakaria M. , Anad Noori. S. , Attallah Mohamed , El-Bahnasawy Hany. H. 
Published: January 2023

AbstractPolymer nanocomposites exhibit unique physical properties inaccessible from their individual constituents, which are tunable through the type of the polymer matrix, the type and size of the incorporated nanoparticles, and the doping level, and therefore, can be utilized in a wide range of potential applications. Here, we report the fabrication of pure Polyvinyl chloride (PVC) and PVC-based nanocomposites containing different loadings of pure and Cr-doped ZnO nanoparticles, using solvent casting method. Scanning electron microscopy images of the obtained nanocomposite films confirmed the successful incorporation of nanoparticles within the PVC matrix, with higher dispersion quality for the Cr-doped ZnO samples. The prepared nanocomposite samples were found to possess higher thermo-mechanical stability, compared to pure PVC, resulting from the strong interaction between the nanoparticles and polymeric chains, as inferred from their thermogravimetric and dynamic mechanical analysis (TGA and DMA) profiles. Specifically, the temperatures corresponding to the onset and 50% weight loss as well as the glass transition temperature are increased by ~ 88, ~ 34, and ~ 16 °C, respectively, after loading selected amounts of the nanoparticles. In addition to the thermo-mechanical stability, the nanocomposites revealed potentially relevant dielectric response, where the dielectric permittivity exhibits remarkable enhancement, by 400%, compared to pristine PVC. The optical transmission of the PVC is strongly suppressed over the entire visible spectral regime, upon loading the nanoparticles, and its optical band gap (~ 4.1 eV) is red shifted toward the value of pristine ZnO nanoparticles (~ 3.3 eV), while the distinct Cr3+ and Cr6+ optical transitions are preserved for the nanocomposites. The obtained thermo-mechanical stability, required for working devices, together with the here reported improvements in the dielectric response for the nanocomposite samples may alter the typical applications of PVC polymers from being insulating materials to be utilized in energy storage and capacitors manufacture, while the preserved optical properties of the incorporated nanoparticles render these nanocomposites suitable candidates for optoelectronic devices.
An efficient hidden marking approach for forensic and contents verification of digital images
Authors: El-Bendary Mohsen A. M. , Faragallah Osama S. , Nassar Sabry S. 
Published: January 2023

AbstractRecently, forensic tools have been presented for detecting the forged image and illegal image manipulations. This paper presents an efficient and simple image contents verifying approach acting as a forensic technique. The presented approach mechanism is built by adding a hidden mark in a secret images, this mark achieves image integrity verification and detecting the tampering or forgery in the secret/authentic images. The secret/authentic/authentic image is divided to two main partitions, each portion is segmented to small blocks. These blocks in one partition are used to mark the blocks of the second partition using data transform technique. Firstly, the sensitive image is marked according to a self-embedding method. Then, a transform domain is utilized in order to embed a block-based signature into another block of the same image. Common discrete transform domains like DWT, DCT, and DFT are examined individually. Different analyses and comparison measurements are employed. The DCT is proved to be the most suitable and efficient transform domain to be used with the proposed scheme. At the receiver side, the reverse process is performed to verify image integrity. As proved from the experiments, this mark-algorithm is not visible or observable and robust against various attacks.
Modeling and Global Sensitivity Analysis of Strategies to Mitigate Covid-19 Transmission on a Structured College Campus
Authors: Zhao Lihong , Santiago Fabian , Rutter Erica M. , Khatri Shilpa , Sindi Suzanne S. 
Published: January 2023

AbstractIn response to the COVID-19 pandemic, many higher educational institutions moved their courses on-line in hopes of slowing disease spread. The advent of multiple highly-effective vaccines offers the promise of a return to “normal” in-person operations, but it is not clear if—or for how long—campuses should employ non-pharmaceutical interventions such as requiring masks or capping the size of in-person courses. In this study, we develop and fine-tune a model of COVID-19 spread to UC Merced’s student and faculty population. We perform a global sensitivity analysis to consider how both pharmaceutical and non-pharmaceutical interventions impact disease spread. Our work reveals that vaccines alone may not be sufficient to eradicate disease dynamics and that significant contact with an infectious surrounding community will maintain infections on-campus. Our work provides a foundation for higher-education planning allowing campuses to balance the benefits of in-person instruction with the ability to quarantine/isolate infectious individuals.
Valorization of orange peels in a biorefinery loop: recovery of limonene and production of volatile fatty acids and activated carbon
Authors: Rizzioli Fabio , Benedetti Vittoria , Patuzzi Francesco , Baratieri Marco , Bolzonella David , Battista Federico 
Published: January 2023

AbstractOrange peels (OPs) were valorized in a lab-scale biorefinery loop for the recovery of limonene and the subsequent production of volatile fatty acids (VFAs) and activated carbon (AC). Solid/liquid extraction of limonene was optimized using n-hexane at 85 °C with an OPs-to-solvent ratio of 2:1, allowing for a limonene recovery yield of 1.20% w/w. Then, post-extraction OPs were used for the production of both VFAs and AC. For VFA production, a hydraulic retention time (HRT) of 5 days and a total solid (TS) inlet content of 10% w/w were adopted leading to a VFA yield of about 43% gVFAs/gTS. Adsorption tests revealed that, among all the solid matrixes tested, only powdered activated carbon (PAC) was able to discriminate no-VFA compounds and allowed for VFA purification. For AC production, post-extraction OPs were firstly converted into biochar through slow pyrolysis at 550 °C for 1 h and then physically activated with CO2 at 880 °C for 1 h. Extraction did not appreciably affect OP properties, while pyrolysis increased the carbon content (from 43 to 83%) and the heating value (from 17 to 29 MJ/kg) of the material. Physical activation of OP biochar increased its surface area by almost ten times, from 40 to 326 m2/g, proving the effectiveness of the treatment.
Dynamic network sampling for community detection
Authors: Mu Cong , Park Youngser , Priebe Carey E. 
Published: January 2023

AbstractWe propose a dynamic network sampling scheme to optimize block recovery for stochastic blockmodel in the case where it is prohibitively expensive to observe the entire graph. Theoretically, we provide justification of our proposed Chernoff-optimal dynamic sampling scheme via the Chernoff information. Practically, we evaluate the performance, in terms of block recovery, of our method on several real datasets from different domains. Both theoretically and practically results suggest that our method can identify vertices that have the most impact on block structure so that one can only check whether there are edges between them to save significant resources but still recover the block structure.
Examining the importance of existing relationships for co-offending: a temporal network analysis in Bogotá, Colombia (2005–2018)
Authors: Nieto Alberto , Davies Toby , Borrion Hervé 
Published: January 2023

AbstractThis study aims to improve our understanding of criminal accomplice selection by studying the evolution of co-offending networks—i.e., networks that connect those who commit crimes together. To this end, we tested four growth mechanisms (popularity, reinforcement, reciprocity, and triadic closure) on three components observed in a network connecting criminal investigations ($$M = 286$$M=286K) with adult offenders ($$N = 274$$N=274K) in Bogotá (Colombia) between 2005 and 2018. The first component had 4286 offenders (component ‘A’), the second 227 (‘B’), and the third component 211 (‘C’). The evolution of these components was examined using temporal information in tandem with discrete choice models and simulations to understand the mechanisms that could explain how these components grew. The results show that they evolved differently during the period of interest. Popularity yielded negative statistically significant coefficients for ‘A’, suggesting that having more connections reduced the odds of connecting with incoming offenders in this network. Reciprocity and reinforcement yielded mixed results as we observed negative statistically significant coefficients in ‘C’ and positive statistically significant coefficients in ‘A’. Moreover, triadic closure produced positive, statistically significant coefficients in all the networks. The results suggest that a combination of growth mechanisms might explain how co-offending networks grow, highlighting the importance of considering offenders’ network-related characteristics when studying accomplice selection. Besides adding evidence about triadic closure as a universal property of social networks, this result indicates that further analyses are needed to understand better how accomplices shape criminal careers.
RETRACTED ARTICLE: Research on effectiveness of college english blended teaching mode under small private online course based on machine learning
Authors: Wang Ruishu 
Published: January 2023

AbstractMachine learning-based learning effectiveness analysis is an important part of the current analysis of college students’ learning effectiveness and it is directly related to the learning effect. It plays a very important role in the analysis of college students’ learning, and enhances the learning effect of students to the greatest extent. The study aimed to investigate the students’ English learning effectiveness under small private online course (SPOC) teaching mode based on machine learning. The study designed and implemented the blended teaching mode of college English based on SPOC. Next, the study investigated the students’ English learning effectiveness under SPOC teaching mode by an empirical study and analyzed the students’ English learning effectiveness under SPOC teaching mode based on machine learning. The results showed that the students were satisfied with the blended teaching mode of college English based on SPOC and students’ academic English skills, research skills and learning effectiveness were improved in the SPOC-based teaching mode. In order to improve the effect of the blended English teaching mode, teachers need to reconstruct the teaching mode of college English based on the SPOC platform, improve the evaluation mechanism, take advantage of the continuous integration of information technology and college English teaching, and build an innovative English teaching mode in order to improve the quality of college English teaching.
Nanobiochar for the remediation of contaminated soil and water: challenges and opportunities
Authors: Jiang Mengyuan , He Lizhi , Niazi Nabeel Khan , Wang Hailong , Gustave Williamson , Vithanage Meththika , Geng Kun , Shang Hua , Zhang Xiaokai , Wang Zhenyu 
Published: January 2023

AbstractAlthough research on biochar has received increasing attention for environmental and agricultural applications, the significance of nanobiochar for environmental pollutant remediation is poorly understood. In contrast to bulk biochar, nanobiochar has superior physicochemical properties such as high catalytic activity, unique nanostructure, large specific surface area and high mobility in the soil environment. These unique characteristics make nanobiochar an ideal candidate for pollution remediation. Thus far, the research on nanobiochar is still in its infancy and most of the previous studies have only been conducted for exploring its properties and environmental functions. The lack of in-depth summary of nanobiochar’s research direction makes it a challenge for scientists and researchers globally. Hence in this review, we established some key fabrication methods for nanobiochar with a focus on its performance for the removal of pollutants from the environment. We also provided up-to-date information on nanobiochar’s role in environmental remediation and insights into different mechanisms involved in the pollutant removal. Although, nanobiochar application is increasing, the associated drawbacks to the soil ecosystem have not received enough research attention. Therefore, further research is warranted to evaluate the potential environmental risks of nanobiochar before large scale application.
Graphical Abstract
The Death of Myth on Roman Sarcophagi
Authors: Allen Mont 
Published: January 2023

A strange thing happened to Roman sarcophagi in the third century: their Greek mythic imagery vanished. Since the beginning of their production a century earlier, these beautifully carved coffins had featured bold mythological scenes. How do we make sense of this imagery's own death on later sarcophagi, when mythological narratives were truncated, gods and heroes were excised, and genres featuring no mythic content whatsoever came to the fore? What is the significance of such a profound tectonic shift in the Roman funerary imagination for our understanding of Roman history and culture, for the development of its arts, for the passage from the High to the Late Empire and the coming of Christianity, but above all, for the individual Roman women and men who chose this imagery, and who took it with them to the grave? In this book, Mont Allen offers the clues that aid in resolving this mystery.
Recognizability of morphisms
Authors: BÉAL MARIE-PIERRE , PERRIN DOMINIQUE , RESTIVO ANTONIO 
Published: January 2023

AbstractWe investigate several questions related to the notion of recognizable morphism. The main result is a new proof of Mossé’s theorem and actually of a generalization to a more general class of morphisms due to Berthé et al [Recognizability for sequences of morphisms. Ergod. Th. & Dynam. Sys.39(11) (2019), 2896–2931]. We actually prove the result of Berthé et al for the most general class of morphisms, including ones with erasable letters. Our result is derived from a result concerning elementary morphisms for which we also provide a new proof. We also prove some new results which allow us to formulate the property of recognizability in terms of finite automata. We use this characterization to show that for an injective morphism, the property of being recognizable on the full shift for aperiodic points is decidable.
ON THE NUMBER OF ALGEBRAIC POINTS ON THE GRAPH OF THE WEIERSTRASS SIGMA FUNCTIONS
Authors: SENA GOREKH PRASAD , KUMAR K. SENTHIL 
Published: January 2023

AbstractLet
$\Omega =\mathbb {Z}\omega _1+\mathbb {Z}\omega _2$
be a lattice in
$\mathbb {C}$
with invariants
$g_2,g_3$
and
$\sigma _{\Omega }(z)$
the associated Weierstrass
$\sigma $
-function. Let
$\eta _1$
and
$\eta _2$
be the quasi-periods associated to
$\omega _1$
and
$\omega _2$
, respectively. Assuming
$\eta _2/\eta _1$
is a nonzero real number, we give an upper bound for the number of algebraic points on the graph of
$\sigma _{\Omega }(z)$
of bounded degrees and bounded absolute Weil heights in some unbounded region of
$\mathbb {C}$
in the following three cases: (i)
$\omega _1$
and
$\omega _2$
algebraic; (ii)
$g_2$
and
$g_3$
algebraic; (iii) the algebraic points are far from the lattice points.
From savages to snowflakes: Race and the enemies of free speech
Authors: Leigh Darcy 
Published: January 2023

AbstractRight-wing free speech advocacy is increasingly shaping global politics. In IR, free speech has generally been viewed within human rights and international legal frameworks. However, this article shows that contemporary free speech advocates often ignore or oppose human rights and international law, focusing instead on (what they describe as) a defence of the nation state against the enemies of free speech. This article examines this articulation of free speech's enemies: first historically as the ‘savage’ in John Stuart Mill's influential formulation of free speech; and then contemporarily as the ‘snowflake’, ‘mob’, and ‘cultural Marxist’ by elected officials and lobbyists in the UK and US. The article argues that John Stuart Mill's savage is figured within a racialised civilisational hierarchy of degrees of humanity. Today, right-wing free speech advocates extend and reconfigure this hierarchy, imagining the ‘snowflake’, ‘mob’, and ‘cultural Marxist’ as lesser human, subhuman, and extra-human, respectively. Thus, in contrast to rights-based analyses of free speech advocacy – which assume or assess the promotion of rights as a ‘public good’ – the article argues that narratives of free speech's enemies are deployed by right-wing free speech advocates to underwrite racialised policy responses and global hierarchies.
How effective is second language incidental vocabulary learning? A meta-analysis
Authors: Webb Stuart , Uchihara Takumi , Yanagisawa Akifumi 
Published: January 2023

AbstractThere is a great deal of variation in gains found between studies of second language (L2) incidental vocabulary learning, as well as many factors that affect learning. This meta-analysis investigated the effects of exposure to L2 meaning-focused input on incidental vocabulary learning with an aim to clarify the proportional gains that occur through meaning-focused learning. Twenty-four primary studies were retrieved providing 29 different effect sizes and a total sample size of 2,771 participants (1,517 in experimental groups vs. 1,254 in control groups). Results showed large overall effects for incidental vocabulary learning on first and follow-up posttests. Mean proportions of target words learned ranged from 9–18% on immediate posttests, and 6–17% on delayed posttests. Incidental L2 vocabulary learning gains were similar across reading (17%, 15%), listening (15%, 13%), and reading while listening (13%, 17%) conditions on immediate and delayed posttest. In contrast, the proportion of words learned in viewing conditions on immediate posttests was smaller (7%, 5%). Findings also revealed that the amount of incidental learning varies according to a range of moderator variables including learner characteristics (L2 proficiency, institutional levels), materials (text type and audience), learning activities (spacing, mode of input), and methodological features (approaches to controlling prior word knowledge).
Regulatory Chill and Domestic Law: Mining in the Santurbán Páramo
Authors: Sands Anna 
Published: January 2023

AbstractA persisting question about investment treaties is whether they lead to regulatory chill – the reluctance to regulate on environmental and social issues due to fear of investment claims. The literature on this topic has been predominantly focussed on how the state responds to international pressures, and little has been written about what happens within the state itself. This article aims to fill that gap by analysing the interplay of domestic laws and institutions in the context of potential investment claims, based on the case study of mining in the Santurbán páramo region in Colombia. The article shows that even though Colombia had created laws and institutions that internalized international investment law, it did not bring about regulatory chill in the case of Santurbán; this is due to the role of domestic constitutional law and the Constitutional Court. This case study also adds to the understanding of how the Liberal International Order is shifting from international to domestic governance, by showing how domestic laws and institutions can have diverging priorities when determining how the risk of investment claims is dealt with.
Fate of Rainfall Over the North Indian States in the 1.5 and 2°C Warming Scenarios
Authors: Pattnayak Kanhu Charan , Awasthi Amit , Sharma Kuldeep , Pattnayak Bibhuti Bhusan 
Published: January 2023

AbstractRise in mean temperature put a great deal of uncertainty about how weather and climate extremes may play out, particularly in India's varied climatic zones. Consequently, it is important to understand the possible changes in both magnitude and direction of weather and climate extremes like rainfall for different warming levels of 1.5 and 2°C scenarios concerning preindustrial and present levels. Hence in the present study, the precipitation behavior of seven North Indian states that is, Haryana, Himachal Pradesh, J&K, Punjab, Rajasthan, Uttar Pradesh, and Uttarakhand carefully studied using CMIP5 models. Future projections of precipitation has been done for the Paris Agreement global warming level of 1.5 and 2°C scenarios. Along with model validation and future projections of precipitation, the return period of extreme rainfall is also discussed to understand the behavior of the occurrence of extreme precipitation. Statistical analysis shows that the ensemble means have the least error as compared to the other six CMIP5 models. Therefore, future analysis has been done with the ensemble mean. Our findings show that the precipitation is likely to decrease in the 1.5°C scenarios, while it is likely to increase in the 2°C scenarios. The occurrence and intensity of extreme rainfall events are likely to be more frequent in all the models. The return period of the extreme rainfall events is likely to increase in all the states in both the warming scenarios. A three‐fold rise is likely to increase extreme rainfall events in the 2°C scenario.
Triggering of Whistler‐Mode Rising and Falling Tone Emissions in a Homogeneous Magnetic Field
Authors: Fujiwara Yuya , Omura Yoshiharu , Nogi Takeshi 
Published: January 2023

AbstractWe perform a self‐consistent one‐dimensional electromagnetic particle simulation with a uniform magnetic field and open boundaries. The plasma environment consists of cold isotropic electrons, energetic electrons, and immobile ions. The energetic electrons are initialized with a subtracted‐Maxwellian distribution with temperature anisotropy. By oscillating external currents with a constant frequency 0.2 fce, where fce is the electron cyclotron frequency, a whistler‐mode wave is injected as a triggering wave from the center of the simulation system, and we investigated the process of interactions between the triggering wave and energetic electrons. We find that both rising‐tone and falling‐tone emissions are triggered through the formation of an electron hole and an electron hill in the velocity phase space consisting of a parallel velocity and the gyro‐phase angle of the perpendicular velocities. The rising‐tone emission varies from 0.2 fce to 0.4 fce, while the falling‐tone varies from 0.2 fce to 0.15 fce. The generation region of the rising‐tone triggered emission starts near the injection point of the triggering wave and moves upstream generating new subpackets. The generation region of the falling‐tone triggered emission also moves upstream generating new subpackets. The simultaneous formation of the electron hole and hill is identified by separating small and large wavenumber components corresponding to lower and higher frequencies, respectively, by applying the discrete Fourier transformation to the waveforms in space. Based on the simulation results of the whistler‐mode triggered emissions, we conclude that the mechanism of frequency variation of whistler‐mode chorus emissions works even in a uniform magnetic field.