bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic coarse-graining of polymer systems using mobility functions
Authors: Li Bing , Daoulas Kostas , Schmid Friederike 
Published: March 2021

Abstract
We propose a dynamic coarse-graining (CG) scheme for mapping heterogeneous polymer fluids onto extremely CG models in a dynamically consistent manner. The idea is to use as target function for the mapping a wave-vector dependent mobility function derived from the single-chain dynamic structure factor, which is calculated in the microscopic reference system. In previous work, we have shown that dynamic density functional calculations based on this mobility function can accurately reproduce the order/disorder kinetics in polymer melts, thus it is a suitable starting point for dynamic mapping. To enable the mapping over a range of relevant wave vectors, we propose to modify the CG dynamics by introducing internal friction parameters that slow down the CG monomer dynamics on local scales, without affecting the static equilibrium structure of the system. We illustrate and discuss the method using the example of infinitely long linear Rouse polymers mapped onto ultrashort CG chains. We show that our method can be used to construct dynamically consistent CG models for homopolymers with CG chain length N = 4, whereas for copolymers, longer CG chain lengths are necessary.
Density-functional-theory approach to the Hamiltonian adaptive resolution simulation method
Authors: Baptista L A , Dutta R C , Sevilla M , Heidari M , Potestio R , Kremer K , Cortes-Huerto R 
Published: March 2021

Abstract
In the Hamiltonian adaptive resolution simulation method (H–AdResS) it is possible to simulate coexisting atomistic (AT) and ideal gas representations of a physical system that belong to different subdomains within the simulation box. The Hamiltonian includes a field that bridges both models by smoothly switching on (off) the intermolecular potential as particles enter (leave) the AT region. In practice, external one-body forces are calculated and applied to enforce a reference density throughout the simulation box, and the resulting external potential adds up to the Hamiltonian. This procedure suggests an apparent dependence of the final Hamiltonian on the system’s thermodynamic state that challenges the method’s statistical mechanics consistency. In this paper, we explicitly include an external potential that depends on the switching function. Hence, we build a grand canonical potential for this inhomogeneous system to find the equivalence between H–AdResS and density functional theory (DFT). We thus verify that the external potential inducing a constant density profile is equal to the system’s excess chemical potential. Given DFT’s one-to-one correspondence between external potential and equilibrium density, we find that a Hamiltonian description of the system is compatible with the numerical implementation based on enforcing the reference density across the simulation box. In the second part of the manuscript, we focus on assessing our approach’s convergence and computing efficiency concerning various model parameters, including sample size and solute concentrations. To this aim, we compute the excess chemical potential of water, aqueous urea solutions and Lennard–Jones (LJ) mixtures. The results’ convergence and accuracy are convincing in all cases, thus emphasising the method’s robustness and capabilities.
Dose quantities for measurement and comparison of doses to individual patients in computed tomography (CT)
Authors: Martin Colin J , Abuhaimed Abdullah , Lee Choonsik 
Published: March 2021

Abstract
The dose quantities displayed routinely on CT scanners, the volume averaged CT dose index (CTDIvol) and dose length product, provide measures of doses calculated for standard phantoms. The American Association of Medical Physics has published conversion factors for the adjustment of CTDIvol to take account of variations in patient size, the results being termed size-specific dose estimate (SSDE). However, CTDIvol and SSDE, while useful in comparing and optimising doses from a set procedure, do not provide risk-related information that takes account of the organs and tissues irradiated and associated cancer risks. A derivative of effective dose that takes account of differences in body and organ sizes and masses, referred to here as size-specific effective dose (SED), can provide such information. Data on organ doses from NCICT software that is based on Monte Carlo simulations of CT scans for 193 adult phantoms have been used to compute values of SED for CT examinations of the trunk and results compared with corresponding values of SSDE. Relationships within ±8% were observed between SED and SSDE for scans extending over similar regions for phantoms with a wide range of sizes. Coefficients have been derived from fits of the data to estimate SED values from SSDEs for different regions of the body for scans of standard lengths based on patient height. A method developed to take account of differences in scan length gave SED results within ±5% of values calculated using the NCI phantom library. This approach could potentially be used to estimate SED from SSDE values, allowing their display at the time a CT scan is performed.
Synthesis and characterization of Gd2O3: Er3+, Yb3+ doped with Mg2+, Li+ ions—effect on the photoluminescence and biological applications
Authors: Kamińska Izabela , Wosztyl Aleksandra , Kowalik Przemysław , Sikora Bożena , Wojciechowski Tomasz , Sobczak Kamil , Minikayev Roman , Zajdel Karolina , Chojnacki Michał , Zaleszczyk Wojciech , Łysiak Katarzyna , Paszkowicz Wojciech , Szczytko Jacek , Frontczak-Baniewicz Małgorzata , Stryczniewicz Wit , Fronc Krzysztof 
Published: March 2021

Abstract
Gd2O3:1% Er3+, 18% Yb3+, x% Mg2+ (x = 0; 2.5; 4; 5; 6; 8;10; 20; 25; 50) and Gd2O3:1% Er3+, 18% Yb3+, 2,5% Mg2+, y% Li+ (y = 0.5–2.5) nanoparticles were synthesized by homogenous precipitation method and calcined at 900 °C for 3 h in air atmosphere. Powder x-ray diffraction, scanning electron microscopy, cathodoluminescence, transmission electron microscopy, energy dispersive x-ray spectroscopy and photoluminescence techniques were employed to characterize the obtained nanoparticles. We observed a 8-fold increase in red luminescence for samples suspended in DMSO solution for 2.5% of Mg2+ doping. The x-ray analysis shows that for the concentration of 2.5% Mg, the size of the crystallites in the NPs is the largest, which is mainly responsible for the increase in the intensity of the upconversion luminescence. But the addition of Li+ ions did not improve the luminescence of the upconversion due to decreasing of crystallites size of the NPs. Synthesized nanomaterials with very effective upconverting luminescence, can act as luminescent markers in in vivo imaging. The cytotoxicity of the nanoparticles was evaluated on the 4T1 cell line for the first time.
On the law of the iterated logarithm for continued fractions with sequentially restricted partial quotients
Authors: Stadlbauer Manuel , Zhang Xuan 
Published: March 2021

Abstract
We establish a law of the iterated logarithm (LIL) for the set of real numbers whose nth partial quotient is bigger than α

n
, where (α

n
) is a sequence such that ∑1/α

n
is finite. This set is shown to have Hausdorff dimension 1/2 in many cases and the measure in LIL is absolutely continuous to the Hausdorff measure. The result is obtained as an application of a strong invariance principle for unbounded observables on the limit set of a sequential iterated function system.
Ultra-fast growth (up to 100 nm s−1) of heavily doped EuBa2Cu3O7 film with highly aligned BaHfO3 nanocolumn structure
Authors: Wu Yue , Jiang Guangyu , Zhu Jiamin , Wu Donghong , Quan Xueling , Shi Jiangtao , Suo Hongli , Zhao Yue 
Published: March 2021

Abstract
Ultra-fast growth (up to 100 nm s−1) of high temperature superconducting film was demonstrated by using an advanced pulsed laser deposition technique. Highly textured EuBa2Cu3O7−δ
(EuBCO) film with 8 mol.% of BaHfO3 (BHO) was deposited on the IBAD-based Hastelloy substrates. Structure characterizations reveal formation of high density of BHO nanocolumns with diameter of ∼5 nm in the film, which is well beyond the expectation. Comparison study on different amount of BHO in EBCO film confirmed that nanocolumn formation strongly depends on the dopant level. The epitaxial growth process of BHO is dominated by ultra-fast self-assembly associated with enhanced diffusion of high flux element and liquid phase. Due to the correlated pinning landscape, a pronounced broad peak appears at B//c in the J
c(θ) curves at 30 K 5 T, while a strong pinning force of about 900 GN m−3 at 4.2 K, 10 T (B//c) are achieved.
Low‐purity Cu and Al sheathed multi‐core MgB2 wires made by IMD process
Authors: Kováč P , Kováč J , Perez N , Scheiter J , Búran M , Kopera L , Hušek I , Melišek T , Berek D 
Published: March 2021

Abstract
Up to now, the highest current densities of MgB2 superconducting wires have been obtained by the internal magnesium diffusion (IMD) method. MgB2 superconductors are especially suitable for DC or AC windings generating low or medium magnetic fields, where thermal stability and low AC losses are important issues. Mechanical, thermal and electrical parameters of the wires are strongly influenced by metallic materials used for the outer sheath. While highly electrical conductive sheath material is beneficial for thermally stable behaviour, it has a great effect on the generation of high eddy current losses. To minimize the contribution of eddy current losses, multi-core MgB2 wires with low purity Cu and Al sheaths were prepared by the IMD process and characterized in detail. Results of low temperature measurements are analysed and discussed in the present work.
Chiral-induced spin selectivity in the formation and recombination of radical pairs: cryptochrome magnetoreception and EPR detection
Authors: Luo Jiate , Hore P J 
Published: March 2021

Abstract
That the rates and yields of reactions of organic radicals can be spin dependent is well known in the context of the radical pair mechanism (RPM). Less well known, but still well established, is the chiral-induced spin selectivity (CISS) effect in which chiral molecules act as spin filters that preferentially transmit electrons with spins polarized parallel or antiparallel to their direction of motion. Starting from the assumption that CISS can arise in electron transfer reactions of radical pairs, we propose a simple way to include CISS in conventional models of radical pair spin dynamics. We show that CISS can (a) increase the sensitivity of radical pairs to the direction of a weak external magnetic field, (b) change the dependence of the magnetic field effect on the reaction rate constants, and (c) destroy the field-inversion symmetry characteristic of the RPM. We argue that CISS polarization effects could be observable by EPR (electron paramagnetic resonance) of oriented samples either as differences in continuous wave, time-resolved spectra recorded with the spectrometer field parallel or perpendicular to the CISS quantization axis or as signals in the in-phase channel of an out-of-phase ESEEM (electron spin echo envelope modulation) experiment. Finally we assess whether CISS might be relevant to the hypothesis that the magnetic compass of migratory songbirds relies on photochemically-formed radical pairs in cryptochrome flavoproteins. Although CISS effects offer the possibility of evolving a more sensitive or precise compass, the associated lack of field-inversion symmetry has not hitherto been observed in behavioural experiments. In addition, it may no longer be safe to assume that the observation of a polar magnetic compass response in an animal can be used as evidence against a radical pair sensory mechanism.
Optimal COVID-19 infection spread under low temperature, dry air, and low UV radiation
Authors: Asher Eitan E , Ashkenazy Yosef , Havlin Shlomo , Sela Alon 
Published: March 2021

Abstract
The COVID-19 pandemic, caused by the novel coronavirus SARS-CoV-2, is spreading rapidly throughout the world, causing many deaths and severe economic damage. It is believed that hot and humid conditions do not favor the novel coronavirus, yet this is still under debate due to many uncertainties associated with the COVID-19 data. Here we propose surrogate data tests to examine the preference of this virus to spread under different climate conditions. We find, by mainly studying the relative number of COVID-19 deaths, that the disease is significantly (above the 95% confidence level) more common when the temperature is ∼10 °C, the relative humidity is ∼60%, the specific humidity is ∼5 g kg−1, and the ultraviolet radiation is less than ∼50 kJ m−2 (per hour). We also find, but less significantly, that the relative number of COVID-19 deaths is high when the wind is weak and low when the wind is strong. The results are supported based on global and regional data, spanning the time period from January to December 2020. The COVID-19 data includes the daily reported new cases and the daily deaths; for both, the population size is either taken into account or ignored.
Keller box study for inclined magnetically driven Casson nanofluid over a stretching sheet: single phase model
Authors: Jamshed Wasim , Karatas Akgül Esra , Sooppy Nisar Kottakkaran 
Published: March 2021

Abstract
The current analysis signifies the Casson nanofluid stream with inclined magnetohydrodynamics, viscous dissipation, joule heating, thermal radiation, particle shape factor effects over a moving flat horizontal surface with entropy analysis. This study presents a novel idea regarding the implementation of Tiwari and Das model on Casson fluid model by considering ethylene glycol as a base fluid. Tiwari and Das model considers nanoparticles volume fraction for heat transfer enhancement instead of the Buongiorno model which heavily relies on thermophoresis and Brownian diffusion effects for heat transfer analysis. The velocity slip and convective slip boundary conditions have been employed at the surface of the sheet. By utilizing the suitable transformations, the modeled PDEs (partial-differential equations) are renewed in ODEs (ordinary-differential equations) and treated these equations numerically with the help of classical Keller box method. Two different classes of nanofluids, Copper-Ethylene Glycol (

C
u
−
EG

) and Molybdenum Disulfide-Ethylene Glycol (

M
o

S

2

−
EG

) have been taken into considering for our analysis. The behaviour of surface drag coefficient and Nusselt number for the varied values of various sundry parameters is designed via tables. Our findings show that an increase in the Reynolds and Brinkman numbers increased the overall entropy of the system.
A mathematical model of torsional vibrations of SWCNTs incorporating surface irregularity effects
Authors: Selim Mahmoud M , Nofal Taher A 
Published: March 2021

Abstract
The aim of the present work is to investigate the surface irregularity effects on torsional vibrations of single-walled carbon nanotubes (SWCNTs). Equation of motion and corresponding closed form solutions were derived based Hamilton’s model. The equations of motion are solved analytically and the influence of surface irregularity on the natural frequency of torsional vibrations of SWCNTs is studied in detail. Numerical caculations were performed for chiral graphene SWCNT of (12, 6) and the results of torsional vibrations were discussed and presented graphically. The obtained numerical results reveal that, the surface irregularity has notable effects on the natural frequency of torsional vibrations of SWCNTs. The impacts of surface irregularities on the natural frequency of nano materials, especially for the natural frequancies of torsional vibration of SWCNTs, have not been studied and most of previous studied were carried out for regular carbon nanotubes. In this sense, the present study is novel, and it is expected that the results obtained will be useful in the design and analysis of the torsional vibration of carbon nanotubes (CNTs) and nanostructures.
Extended hydrodynamics of degenerate partially spin polarized fermions with short-range interaction up to the third order by interaction radius approximation
Authors: Andreev Pavel A 
Published: March 2021

Abstract
The possibility of the hydrodynamic description of ultracold fermions via the microscopic derivation of the model is described. Differently truncated hydrodynamic models are derived and compared. All models are based on the microscopic many-particle Schrödinger equation. Minimal coupling models based on the continuity and Euler equations are considered. An extended hydrodynamic model including the independent dynamics of the momentum flux (the pressure evolution) is derived. The influence of the spin polarization is described. The short-range interaction is considered in the isotropic limit. The interaction is considered up to the third order by interaction radius. Therefore, the single-fluid model of spin-1/2 fermions and the two-fluid model of spin-1/2 fermions are under consideration in this paper. Spectra of bulk collective excitations are derived and compared in terms of different models.
Effect of Temperature-Dependent Blood Viscosity on Low-Density Lipoprotein Transport: Numerical Study
Authors: Piemjaiswang R , Ding Y , Feng Y , Chalermsinsuwan B 
Published: March 2021

Abstract
The blood viscosity is correlated with the risk of developing atherosclerotic lesions. The environmental factor can play an important role in altering hemodynamics and low-density lipoprotein (LDL) especially the ambient temperature. The greenhouse gas emission from energy or power production can increase the ambient temperature. This study investigated the effect of temperature-dependent blood viscosity on the LDL transport within the axisymmetric artery with a 40% stenosis blockage via computational fluid dynamics simulation. The results showed that the changing of blood viscosity inducing the change in pressure drop. The penetration locations of the LDL were also shifted which increased the risk of having LDL penetrating into the arterial wall. In addition, the outcome will contribute to the initial development of atherosclerosis modelling.
Fuzzy Logic and Simple Additive Weighting Implementation on River Flow Controlling System
Authors: Hannats Hanafi Ichsan Mochammad , Edo Prasetya Adven 
Published: March 2021

Abstract
Floods are natural disasters that are very difficult to predict and come from a variety of factors. One of the causes of flooding is an increase in the amount of water discharge. The water discharge comes from various sources, among which the most is high water in rivers and high rainfall. While the river is a system of water that flows from upstream to highlands to downstream in the lowlands with a very long and has branched routes. Fuzzy logic is logic that can overcome ambiguous matters, in this case, rainfall and water discharge. In river branching, river opening and closing systems are needed to prevent rain, so the Simple Additive Weighting (SAW) algorithm is used. In this research prototyping was carried out to implement Fuzzy Logic and SAW for sluice control, using the Water Level Sensor and the Rain Sensor Module to control the Servo Motor. Servo Motor is used to control the opening and height of sluice openings. This study as a whole system has an error of 0.099% so that the prototype system can be categorized quite well and can be applied for further research.
Modeling the Shape of the Roll Contact Curves in Two-Roll Modules
Authors: Khurramov Sh.R. , Abdukarimov A. , Khalturaev F.S. , Kurbanova F.Z. 
Published: March 2021

Abstract
The study is devoted to mathematical modeling of the shape of the roll contact curves in two-roll modules. A two-roll module is considered, in which the rolls are positioned relative to the vertical with a tilt to the right, have unequal diameters and elastic coatings from the materials of different stiffness and friction coefficients, the material layer is fed with a tilt downward relative to the center line. The equations of the curves of roll contact in the considered two-roll module are derived. It is revealed that the obtained models are general in the sense that they are applicable for particular cases of interaction in a two-roll module.
A Strict Total Order and Derived Distance Function for Multivariate Finite Data Based on Data-derived Analytical Meshes
Authors: Chen Ray-Ming 
Published: March 2021

Abstract
In this article, we show a way to linearize a set of finite multivariate data set. Such linearization utilizes analytical meshes, which are defined based on a given data, and associated forward walking paths related to the defined meshes. It further yields a strict linear ordering and a simple distance function via such walking paths and lengths for the given data set. This strict linear ordering and distance function could be applied in grouping the data set with respect to some optimal criteria.
How Does Teacher Continues Professional Development Practices Help Teachers To Become Competent? Validating Models: A Structural Equation Modeling Approach
Authors: Ramanan Banu , Mohamad Mua’azam Bin 
Published: March 2021

Abstract
This study aimed to validate the instrument of teacher continuous professional development practices (TCPD) and teacher competence to become a quality educator. The instruments were divided into five main dimensions for TCPD and seven dimensions for teacher competence use confirmatory factor analysis (CFA). The study utilized a cross-sectional design involving 383 primary and secondary school teachers selected through stratified random sampling from eastern coastal states in Malaysia. The instrument for this study used a seven-point Likert scale. The hypothesis was tested with a measurement model using IBM SPSS SEM-AMOS version 24.0. Items identified as having low factor loadings were dropped. This finding indicates that the final measurement model is compatible with the data obtained. This model meets the requirements of reliability and constructs validity, convergent validity and discriminant validity. In conclusion, this measurement model could measure the degree of TCPD and the competency level of teachers in order to become a quality educator. The findings of this study have implications for the importance of professional development as ongoing growth which plays a crucial role in student turn over.
The Competency of Science Teachers in Integrating Higher Order Thinking Skills in Teaching and Learning
Authors: Ab Halim A S , Osman K , Aziz M S A Mohd , Ibrahim M F , Ahmad A A K 
Published: March 2021

Abstract
The performance of an individual will increase if he has all the competencies required to carry out his duties and responsibilities. This survey study was conducted to identify the competency of science teachers in integrating Higher Order Thinking Skills (HOTS) in teaching and learning. The competency of science teachers is seen in three aspects based on the Iceberg Model which are knowledge, skills and attitude. 39 science teachers from 27 secondary schools in Besut district have responded to the questionnaire instrument disseminated in this study. Descriptive statistics were used to analyse the frequency and percentage of respondent profiles involved. Descriptive statistics were also used to obtain mean and standard deviation to determine the competency level of respondents in HOTS. Analysis shows the level of competency of science teachers in terms of knowledge and attitude is high. The skills aspect shows a moderate level. The study suggested that science teachers did not explore various strategies and approaches in implementing HOTS. The high level of knowledge and attitudes should be manifested through teaching and learning that combines different approaches, questions with various cognitive level and activities that challenge the students’ thinking. This study provides a room for improvement for science teachers in enhancing the quality of teaching and learning and nurturing HOTS in students.