Miracle-dz/UniFAR-FTUs huggingface dataset:
Investigation of Electrocatalytic behavior of mesoporous strontium selenide nanowires for hydrogen evolution reaction

Tremendous efforts have been directed to synthesize electrocatalysts for hydrogen evolution reaction but the electrocatalytic behavior of alkaline metal‐based selenides has been rarely reported. Herein, SrSe nanowires have been synthesized using the solvo‐hydrothermal process at various temperatures, and the synthesis has been confirmed using different techniques. The employed temperature affects the structure of the strontium selenides and has significantly influenced the hydrogen evolution reaction. Owing to the mesoporous nature and the greater specific and electrochemical surface area, the SrSe nanowires synthesized at 200°C exhibit a greater number of active sites and show an overpotential of 127 mV to approach the current density of 10 mA cm−2 in 1 M KOH electrolyte. The SrSe nanowires also exhibit a greater turnover frequency of 41.20 ms−1 at the fixed reversible hydrogen electrode potential of 500 mV. The electrocatalyst SrSe nanowires reveal a Tafel slope of 135 mV dec−1, which is better than synthesis at other temperatures. The SrSe nanowires maintained the current density for 24 h chronoamperometry test in 1 M KOH electrolyte. The test results inspire further investigation and indicate the leading potential of SrSe nanowires for hydrogen evolution application.
A Zero-Transient Dual-Frequency Control for Class-E Resonant DC–DC Converters

In this article, a dual-frequency control method for regulating the output power in class-E resonant dc–dc converters has been introduced. As in the standard on–off control or other recently proposed dual-frequency controls, the approach is based on the ability of the converter to alternately operate in a high- and a low-power state. The proposed solution has a twofold advantage: on the one hand, soft-switching capabilities (i.e., zero-voltage and zero-voltage-derivative switching) are preserved in both operating states; on the other hand, it is possible to reduce to zero the transient time required to switch from one state to the other one. The most straightforward consequence is the possibility to increase to very large values the frequency at which the two operating states are switched, up to the same order of magnitude as the main switching frequency of the converter. In this way, the additional ripple introduced by the proposed dual-frequency control can be decreased to a negligible value. The approach has been validated by measurements on a prototype operating between 4 and 8 MHz and in which it has been possible to increase the control frequency up to 500 kHz.
Variable Frequency Isolated Bidirectional CLLC Resonant Converter With Voltage Controlled Variable Capacitors

This article proposes a novel variable frequency isolated bidirectional CLLC resonant converter with voltage-controlled variable capacitors (VCVCs) and auxiliary clamp circuits (ACCs). By employing the class II ceramic capacitors as VCVCs, the converter's modes in one switching cycle and the transient process to set up the dc voltage bias on VCVCs are analyzed in detail to explain the fundamental principles and lossless characteristics of ACCs in the steady state. Suitable ranges of capacitor voltage stress and current stress and gain characteristics of the converter are also given to design the resonant parameters. The converter's soft-switching characteristics, fast transient process, and high efficiency are well demonstrated by the experimental results obtained on a 500 W prototype. The high-efficiency range of the proposed converter with the VCVCs is 20%–100%, which is at least 10% wider than the others without VCVCs.
Tensile-Force-Resilient Biomedical Front-End Circuits Employing Auto-Calibrated Omni-Directional Thin-Film Transistors

Flexible electronics based on thin film transistors (TFTs) are expected to deliver important benefits in the mobile healthcare field. Nevertheless, the mechanical strain caused by the respiration or movement of organisms seriously affects the characteristics of the TFTs, and thus deteriorates the performance of TFT-based circuits and systems. Taking indium-gallium-zinc-oxide (IGZO) TFT as an example, this paper proposes a tensile-force-resilient biomedical front-end system based on omni-directional thin film transistors (OD TFTs). The proposed OD TFT is a combination of dual gate TFTs with optimized layout, whose force-insensitive axis can be adjusted by the biasing of top gate. Based on this, an auto calibration technique in front-end system is introduced, which can automatically adjust the top gate biasing of OD TFTs according to the Poisson's ratio of substrate and the direction of external force, so as to align the force-insensitive axis along the direction of external force. Employing the OD TFTs in circuits and the auto calibration technique, the force resilience of the flexible electronic system is significantly improved in practical applications. The simulations of front-end system on acquiring electrocardiogram (ECG) and electromyogram (EMG) signals are performed. The results show that the proposed front-end system with auto calibration provides an increase of SNR from initial −19.91 dB and −25.89 dB without calibration to 17.53 dB and 1.32 dB in two cases, respectively.
A Model Stacking Approach for Forecasting Mortality

This article adopts a machine learning method called stacked generalization for forecasting mortality. The main idea is to combine the forecasts from different projection models or algorithms in a certain way in order to increase the prediction accuracy. In particular, the article considers not just the traditionally used mortality projection models, such as the Lee–Carter and CBD models and their extensions, but also some learning algorithms called feedforward and recurrent neural networks that are starting to gain attention in the actuarial literature. For blending the different forecasts, the article examines a number of choices, including simple averaging, weighted averaging, linear regression, and neural network. Using U.S. mortality data, it is found that the proposed stacking approach often outperforms the cases where a projection model or algorithm is applied individually, and that neural networks tend to generate better results than many of the traditional models.
A Study to Understand Parents' Perceptions and Societal Attitudes on Bharat Biotech’s Covaxin for Children

he recent COVID-19 pandemic has reshaped the perceptions of vaccines worldwide. Presently, vaccines are the most efficacious resource that holds the strength to reduce the risk of the disease. In contrast, public health authorities are concerned about vaccine apprehension among the general public. The distribution and consumption of these vaccines began by segregating the age groups. The eligibility of Covaxin vaccines manufactured by Bharat Biotech for children over 12 years of age makes it critical to investigate its credibility among the parents and public views regarding children receiving these vaccines. Moreover, limited information on public acceptability and trustable opinions contribute to vaccine hesitancy among parents. Consequently, the major deciding factors are getting accurate data about the Covaxin’s clinical trial by Bharat Biotech, the persistence and nature of the child's immune response, and reassurance from society. This research study aims to learn more about parents' perspectives and societal attitudes towards immunity building in children by the Covaxin vaccines. The methodology adopted here leads to a precise understanding if there is any ambiguity or acceptance towards Covaxin for children in the minds of the general public. Keywords Bharat Biotech, Children, Clinical Trial, Covaxin, COVID-19, Immunity, Perception.
The Study on Resolution Factors of LPBF Technology for Manufacturing Superelastic NiTi Endodontic Files

Laser Powder Bed Fusion (LPBF) technology is a new trend in manufacturing complex geometric structures from metals. This technology allows producing topologically optimized parts for aerospace, medical and industrial sectors where a high performance-to-weight ratio is required. Commonly the feature size for such applications is higher than 300–400 microns. However, for several possible applications of LPBF technology, for example, microfluidic devices, stents for coronary vessels, porous filters, dentistry, etc., a significant increase in the resolution is required. This work is aimed to study the resolution factors of LPBF technology for the manufacturing of superelastic instruments for endodontic treatment, namely Self-Adjusting Files (SAF). Samples of thin walls with different incline angles and SAF samples were manufactured from Nickel-Titanium pre-alloyed powder with a 15–45 μm fraction. The printing procedure was done using an LPBF set-up equipped with a conventional ytterbium fiber laser with a nominal laser spot diameter of 55 microns. The results reveal physical, apparatus, and software factors limiting the resolution of the LPBF technology. Additionally, XRD and DSC tests were done to study the effect of single track based scanning mode manufacturing on the phase composition and phase transformation temperatures. Found combination of optimal process parameters including laser power of 100 W, scanning speed of 850 mm/s, and layer thickness of 20 μm was suitable for manufacturing SAF files with the required resolution. The results will be helpful for the production of NiTi micro objects based on periodic structures both by the LPBF and μLPBF methods.
Covalent Adaptable Microstructures via Combining Two‐Photon Laser Printing and Alkoxyamine Chemistry: Toward Living 3D Microstructures

Manufacturing programmable materials, whose mechanical properties can be adapted on demand, is highly desired for their application in areas ranging from robotics, to biomedicine, or microfluidics. Herein, the inclusion of dynamic and living bonds, such as alkoxyamines, in a printable formulation suitable for two‐photon 3D laser printing is exploited. On one hand, taking advantage of the dynamic covalent character of alkoxyamines, the nitroxide exchange reaction is investigated. As a consequence, a reduction of the Young´s Modulus by 50%, is measured by nanoindentation. On the other hand, due to its “living” characteristic, the chain extension becomes possible via nitroxide mediated polymerization. In particular, living nitroxide mediated polymerization of styrene results not only in a dramatic increase of the volume (≈8 times) of the 3D printed microstructure but also an increase of the Young's Modulus by two orders of magnitude (from 14 MPa to 2.7 GPa), while maintaining the shape including fine structural details. Thus, the approach introduces a new dimension by enabling to create microstructures with dynamically tunable size and mechanical properties.
Boolean constraints in SICStus Prolog

This report documents the implementation of a Boolean constraint solver and its integration with a Prolog engine. The solver comprises built-in predicates for checking consistency and entailment of a new constraint w.r. t. accumulated constraints and for generating particular solutions to a set of constraints, and extensions to the Prolog top-level for displaying answer constraints. Boolean unification was chosen as the strategy for the consistency check. Boolean unification fits well with the Prolog execution model, and allows the accumulated constraints to be associated in a natural way with the variables being eliminated. The answer constraints are computed by existentially quantifying in the accumulated set of constraints all variables not occurring in the user query. The simplified set of constraints constitutes the answer constraints. Boolean formulas are internally represented as DAGs. Details are provided on this representation and the support for it provides by Prolog Engine. We have investigated various optimizations of the Boolean unification algorithm, and a preliminary performance evaluation is included.
Statistical inference for molecular shapes

This thesis is concerned with developing statistical methods for evaluating and comparing molecular shapes. Techniques from statistical shape analysis serve as a basis for our methods. However, as molecules are fuzzy objects of electron clouds which constantly undergo vibrational motions and conformational changes, these techniques should be modified to be more suitable for the distinctive features of molecular shape. The first part of this thesis is concerned with the continuous nature of molecules. Based on molecular properties which have been measured at the atom positions, a continuous field--based representation of a molecule is obtained using methods from spatial statistics. Within the framework of reproducing kernel Hilbert spaces, a similarity index for two molecular shapes is proposed which can then be used for the pairwise alignment of molecules. The alignment is carried out using Markov chain Monte Carlo methods and posterior inference. In the Bayesian setting, it is also possible to introduce additional parameters (mask vectors) which allow for the fact that only part of the molecules may be similar. We apply our methods to a dataset of 31 steroid molecules which fall into three activity classes with respect to the binding activity to a common receptor protein. To investigate which molecular features distinguish the activity classes, we also propose a generalisation of the pairwise method to the simultaneous alignment of several molecules. The second part of this thesis is concerned with the dynamic aspect of molecular shapes. Here, we consider a dataset containing time series of DNA configurations which have been obtained using molecular dynamic simulations. For each considered DNA duplex, both a damaged and an undamaged version are available, and the objective is to investigate whether or not the damage induces a significant difference to the the mean shape of the molecule. To do so, we consider bootstrap hypothesis tests for the equality of mean shapes. In particular, we investigate the use of a computationally inexpensive algorithm which is based on the Procrustes tangent space. Two versions of this algorithm are proposed. The first version is designed for independent configuration matrices while the second version is specifically designed to accommodate temporal dependence of the configurations within each group and is hence more suitable for the DNA data.
Scientometrics and Science Studies

Scientométrie et étude de sciences. Les auteurs ne peuvent être réduits aux textes et les textes ne peuvent se réduire aux auteurs. C'est dans le développement de réseaux complexes de textes et d'auteurs se répondant les uns les autres que la connaissance émerge et qu'elle peut être repérée. L'objet de la scientométrie est l'étude de l'évolution dans le temps de ces réseaux selon toute leur complexité. Pour décrire et/ou mesurer la science afin de rendre visible la connaissance acquise, il faut rendre compte des conditions suivantes: en premier lieu, utiliser des statistiques non-paramétriques car il est difficile d'envisager des paramètres qui rendraient compte de l'apport de connaissance. Cette connaissance n'est donnée et reproduite qu'en termes d'interactions socio-cognitives (le "modèle statique"). En second lieu, ces interactions sont évalués dans leur dimension temporelle selon ce qu'elles signifient par rapport aux institutions d'une part, et en référence au développement cognitif à l'échelon du réseau d'autre part (les "dynamiques de la science"). La médiation entre les deux points de vue a été améliorée par la codification de la science, par exemple en termes de pratiques de citations ou de réalisation de résumés. Cette codification dans plusieurs directions permet d'envisager un développement de systèmes de bases de connaissances auto-organisés.
Vitamin D and Weight Change: A Mendelian Randomization, Prospective Study

The association between 25-hydroxyvitamin D and 5-, 10-, or 15-year weight change were assessed in a population-based, prospective study conducted in Lausanne, Switzerland. Data from the first (2009–2012, N = 3527, 51.3% women), second (2014–2017, N = 3237, 53.8% women), and third (2018–2021, N = 2567, 54.2% women) follow-ups were used. A weighted genetic risk score (GRS) of 115 SNPs associated with vitamin D levels was constructed. At baseline, the GRS correlated positively with 25-hydroxyvitamin D levels based on a Spearman rank correlation and 95% confidence interval: 0.198 (0.166; 0.231), p < 0.001; and with body mass index: 0.036 (0.004; 0.068), p = 0.028. No association was found between quartiles of GRS and weight changes at 5, 10, or 15 years: multivariate-adjusted weight changes ± SEM at 5-years follow-up were 1.39 ± 0.17, 1.13 ± 0.17, 1.24 ± 0.17, and 1.00 ± 0.17 kg for the first to the fourth quartile of the GRS, respectively (p = 0.401). Two-step linear regression showed a significant but clinically meaningless association between GRS-derived vitamin D and weight change at 5- and 15-years: slope and 95% confidence interval for a 5 nmol/L increase in GRS-derived 25-hydroxyvitamin D levels: 0.082 (0.013; 0.150) and 0.130 (0.018; 0.243) kg, respectively. We conclude that there is little association between genetically determined 25-hydroxyvitamin D levels and weight gain.
Weighted ridge and Liu estimators for linear regression model

In linear regression model, ridge regression and two‐parameter Liu estimator (LE) are the most widely used methods in recent decade to overcome the problem of multicollinearity especially for ill conditioned cases. In this article, we propose new weighted ridge and Liu estimators which remain positive for each level of multicollinearity and also give smaller mean squared error (MSE) than the existing ridge regression and existing Liu estimators. In addition, a new adaptive LE for k which accounts for the error variance is also proposed to assess the ill condition cases. Furthermore, new weighted ridge estimator of Kibria arithmetic mean method and two parameter Liu estimator with Liu method are also proposed. Extensive Monte‐Carlo simulations are used to evaluate the performance of proposed estimators. Based on MSE criterion, the proposed estimators perform better than the existing estimators in many situations including severe multicollinearity and small signal‐to‐ noise ratio. Two real life applications are also provided to illustrate the usefulness of new estimators.
Global Trends and Characteristics of Offshore Wind Farm Research over the Past Three Decades: A Bibliometric Analysis

Offshore wind power is a valuable renewable energy source. However, the development of offshore wind farms is facing many challenges, including understanding their impacts on ecosystems and society, as well as knowledge gaps in research. In this study, a bibliometric analysis was performed with the aim of providing a comprehensive understanding of current global progress in offshore wind farm research. Three stages of development were considered for the analysis and comparison of research characteristics and outcomes. Based on the total number of scientific publications and the international collaboration ratio (ICR), Europe has been leading research in and the development of offshore wind power since the early 1990s. However, a fast-growing period of offshore wind farm development occurred after 2000, during which Europe and Asia in particular showed increases in ICR. The installation of offshore wind turbines may have non-negligible adverse impacts on marine ecosystems, especially in ecologically vulnerable regions or developing countries. Research and relevant studies should be integrated to investigate and reduce the ecological and environmental damage that results from offshore wind farm development. This paper presents a systematic evaluation of the global developmental trends in offshore wind farm research, which could help to characterize and guide future trends within this field.
The stability of planetesimal niches in the outer solar system: a numerical investigation

Planetesimals are objects, such as asteroids and comets, that formed from the early solar nebula and represent an early stage in the planetary accretion process. Planetesimals appear to be absent from the zones between the jovian planets. This could be due to observational bias, an ab initio depletion in the early solar nebula, or perturbations from the jovian planets which destabilize these inter-planet niches over time scales shorter than the age of the Solar System. We computationally tested the third hypothesis, and reconsidered the possible existence of dynamically stable niches in the Jupiter/Saturn, Saturn/Uranus, and Uranus/Neptune zones. Previous computational surveys of these zones have been coarse, employing statistically small numbers of test particles, and introducing many simplifying physical assumptions. We employed a modified 13th order Stormer integrator together with "significance ordered computation" for roundoff error management. We first validated our new numerical techniques, and compared them with popular symplectic mapping methods--confirming their much improved accuracy, albeit at the expense of significantly more computer time. By employing $10\sp5$ particles in the Jupiter/Saturn zone (two orders of magnitude more than in previous studies)--and $10\sp4$ in each of the Saturn/Uranus and Uranus/Neptune zones--on both inclined and eccentric orbits, we performed a more comprehensive search for test particle stability as a function of initial orbital elements. Our increased number of test particles also facilitated robust statistical inference and comparison with results derived from statistical mechanics and kinetic theory. We found that most planetesimals are removed over $10\sp5$ years in the Jupiter/Saturn zone, and $10\sp7$ years in the Saturn/Uranus and Uranus/Neptune zones. Five long-lived regions persisted for $10\sp8$ years, but few planetesimals survived one billion years. Finally, we turned to the issue of the fates of individual particles that were expelled from these jovian niches. We developed two new integration schemes, a time-adaptive multistep method and a new symplectic mapping that exploited the integrability of the Stark effect. Our expectation is that these new tools will be employed in the next generation of Solar System evolution investigations.
Physics at Super B Factory

This report presents the results of studies that investigate the physics reach at a Super B factory, an asymmetric-energy e^+e^- collider with a design luminosity of 5 x 10^35 cm^-2s^-1, which is around 40 times as large as the peak luminosity achieved by the KEKB collider. The studies focus on flavor physics and CP violation measurements that could be carried out in the LHC era. The physics motivation, key observables, measurement methods and expected precisions are presented. The sensitivity studies are a part of the activities associated with the preparation of a Letter of Intent for SuperKEKB, which has been submitted recently. Comment: 191 pages, results of studies by the SuperKEKB Physics Working Group