bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of the field self-interaction of General Relativity on the cosmic microwave background anisotropies
Authors: Deur Alexandre 
Published: May 2022

Abstract
Field self-interactions are at the origin of the non-linearities inherent to General Relativity. We study their effects on the cosmic microwave background (CMB) anisotropies. We find that they can reduce or alleviate the need for dark matter and dark energy in the description of the CMB power spectrum.
Corrosion grade recognition for weathering steel plate based on a convolutional neural network
Authors: Wang Yan , Shen Xiaoli , Wu Kai , Huang Mingquan 
Published: May 2022

Abstract
For the maintenance of weathering steel structure facilities, it is necessary to evaluate the corrosion grade of the rust layer on the surface regularly. At present, corrosion grade classification of weathering steel is mainly based on visual inspection with the human eye. In this paper, a deep learning method using a convolutional neural network (CNN) to evaluate the corrosion grade of weathering steel is proposed to save time and manpower. Firstly, the image dataset of the corrosion steel plate was established using salt spray tests. Then, a CNN architecture named VGG-Corrosion was designed to evaluate the corrosion grade of the corroded steel plate. The effects of the learning rate, transfer learning, and batch size were also investigated to clarify the best hyperparameter configurations to train a powerful corrosion grade classification model. Under the best combination of considered hyperparameters, the mean average accuracy for the corrosion grade evaluation of the test results is 90.96%. The test results indicated that the CNN-based corrosion grade recognition for weathering steel plate is prospective, which would be helpful for safety evaluation of steel structures.
Enhancement of detachment control with simplified real-time modelling on the KSTAR tokamak
Authors: Eldon D , Anand H , Bak J-G , Barr J , Hahn S-H , Jeong J H , Kim H-S , Lee H H , Leonard A W , Sammuli B , Shin G W , Wang H Q 
Published: May 2022

Abstract
Detachment control based on ion saturation current I

sat
measurements from Langmuir probes (LPs) is implemented in the KSTAR tokamak and shown to be capable of following dynamic and constant target trajectories with good accuracy, in H-mode, by moderating the flow rate of nitrogen or deuterium. I

sat
controllers normalize I

sat
in order to form attachment fraction (A

frac
) as their control parameter. The KSTAR implementation of A

frac
control differs from previous work in that it continuously calculates a model for attached I

sat
and uses that as the denominator in A

frac
, whereas prior implementations either record peak I

sat
at rollover as they pass it or take estimated

I

s
a
t
,
r
o
l
l
o
v
e
r

as a manual input prior to the shot. The KSTAR controller therefore does not need to keep track of rollover status and keep separate targets for pre- and post-rollover states, and it can automatically adapt to changes in scenario at any time. It is also less vulnerable to noise as it will not lock in an outlier as a rollover point.
High-frequency measurement of the interferometric phase, the Faraday rotation, and the Cotton-Mouton effect with a single detector in a far-infrared interferometer-polarimeter
Authors: Giudicotti L , Fiorucci D , Zilli E 
Published: May 2022

Abstract
A novel polarization modulation method is proposed, for a possible application in the measurement of the electron density and magnetic field profiles by an interferometer-polarimeter diagnostic in the Divertor Test Tokamak (DTT) device. Starting from the output of a CO2 pumped CHCOH3 far-infrared (FIR) laser (λ = 118.8 μm), three waves with frequencies ω, ω − δω, and ω + δω are generated and coherently combined to produce a polarization modulated laser beam suitable to probe the DTT plasma in a multichord, double-pass scheme. A second, coherently pumped, FIR cavity operating at the slightly detuned ω′ frequency, acts as a local oscillator for the interferometric measurement. By this polarization modulation method, it is possible to simultaneously measure the interferometric phase, the Faraday rotation angle, and the Cotton-Mouton effect, all by a single detector, while keeping to an acceptable value the perturbation of the interferometric phase due to the time modulated polarization. In this paper, we describe the principles of the method and discuss its possible application in the poloidal interferometer-polarimeter diagnostic of the DTT device. A single chord mock-up experiment is in preparation to experimentally test the technique.
Bi-chromaticity and tunability of random lasing in mesoporous silica SBA16 doped with rhodamine B
Authors: Melo Leandro A , Prado Marcus V A , De Vicente Fábio S , Moreno Leandro X , Rodrigues Jr José Joatan , Alencar Márcio A R C 
Published: May 2022

Abstract
The random laser emission from ordered mesoporous silica SBA16 doped with rhodamine B (RB) organic dye was investigated. Powdered SBA16 with 16 nm average pore diameter have been synthesized and doped with five different concentrations of the organic dye. Typical incoherent feedback random laser behavior was observed. The bi-chromatic emission was characterized for the sample with the highest dye concentration. Tunable random laser emissions from 578 to 618 nm were obtained depending on the excitation laser spot diameter and the rhodamine-B load. The results indicate that mesoporous RB-doped SBA16 is a promising material for the development of solid-state random lasers.
Symmetric and antisymmetric vector solitons for the fractional quadric-cubic coupled nonlinear Schrödinger equation
Authors: Xu Jia-Zhen , Cao Qi-Hao , Dai Chao-Qing 
Published: May 2022

Abstract
The fractional quadric-cubic coupled nonlinear Schrödinger equation is concerned, and vector symmetric and antisymmetric soliton solutions are obtained by the square operator method. The relationship between the Lévy index and the amplitudes of vector symmetric and antisymmetric solitons is investigated. Two components of vector symmetric and antisymmetric solitons show a positive and negative trend with the Lévy index, respectively. The stability intervals of these solitons and the propagation constants corresponding to the maximum and minimum instability growth rates are studied. Results indicate that vector symmetric solitons are more stable and have better interference resistance than vector antisymmetric solitons.
Passive double pendulum in the wake of a cylinder forced to rotate emulates a cyclic human walking gait
Authors: Carleton Adrian G , Sup Frank C , Modarres-Sadeghi Yahya 
Published: May 2022

Abstract
The goal of this work is to present a method based on fluid–structure interactions to enforce a desired trajectory on a passive double pendulum. In our experiments, the passive double pendulum represents human thigh and shank segments, and the interaction between the fluid and the structure comes from a hydrofoil attached to the double pendulum and interacting with the vortices that are shed from a cylinder placed upstream. When a cylinder is placed in flow, vortices are shed in the wake of the cylinder. When the cylinder is forced to rotate periodically, the frequency of the vortices that are shed in its wake can be controlled by controlling the frequency of cylinder’s rotation. These vortices exert periodic forces on any structure placed in the wake of this cylinder. In our system, we place a double pendulum fitted with a hydrofoil at its distal end in the wake of a rotating cylinder. The vortices exert periodic forces on this hydrofoil which then forces the double pendulum to oscillate. We control the cylinder to rotate periodically, and measure the displacement of the double pendulum. By comparing the joint positions of the double pendulum with those of human hip, knee and ankle joint positions during walking, we show how the system is able to generate a human walking gait cycle on the double pendulum only using the interactions between the vortices and the hydrofoil.
Mitigating ozone damage to ecosystem productivity through sectoral and regional emission controls: a case study in the Yangtze River Delta, China
Authors: Lei Yadong , Yue Xu , Wang Zhili , Liao Hong , Zhang Lin , Tian Chenguang , Zhou Hao , Zhong Junting , Guo Lifeng , Che Huizheng , Zhang Xiaoye 
Published: May 2022

Abstract
The land ecosystems of China are estimated to provide an important sink for the increased atmospheric carbon dioxide (CO2), but are undermined by severe ozone (O3) pollution. Mitigation of O3 damage to ecosystems remains a challenge considering that O3 precursors are emitted from a wide range of anthropogenic sectors and O3 formations are also affected by regional transport. Here, we combine chemical transport and dynamic vegetation models to quantify the benefits of sectoral and regional emission controls for the recovery of gross primary productivity (GPP) in the Yangtze River Delta (YRD). For sectoral emission controls, the largest mitigation of O3 damage to GPP in YRD by 3.1 ± 0.4 and 2.2 ± 0.2 Gg[C] d−1 with 50% reductions in the emissions from industry and transportation sectors, respectively. For regional emission controls, reducing 50% anthropogenic emissions outside YRD can mitigate GPP losses by 18.6 ± 3.5 Gg[C] d−1, larger than the recovery of 10.1 ± 1.6 Gg[C] d−1 by the 50% reductions of anthropogenic emissions within YRD. Moreover, summer months, especially July are the best period for GPP recovery from anthropogenic emission controls. Our results highlight the importance of sectoral and regional emission controls to mitigate O3 damage to ecosystem productivities in YRD.
Mixed dispersion nonlinear Schrödinger equation in higher dimensions: theoretical analysis and numerical computations
Authors: Stefanov Atanas , Tsolias Georgios A , Cuevas-Maraver Jesús , Kevrekidis Panayotis G 
Published: May 2022

Abstract
In the present work we provide a characterization of the ground states of a higher-dimensional quadratic-quartic model of the nonlinear Schrödinger class with a combination of a focusing biharmonic operator with either an isotropic or an anisotropic defocusing Laplacian operator (at the linear level) and power-law nonlinearity. Examining principally the prototypical example of dimension d = 2, we find that instability arises beyond a certain threshold coefficient of the Laplacian between the cubic and quintic cases, while all solutions are stable for powers below the cubic. Above the quintic, and up to a critical nonlinearity exponent p, there exists a progressively narrowing range of stable frequencies. Finally, above the critical p all solutions are unstable. The picture is rather similar in the anisotropic case, with the difference that even before the cubic case, the numerical computations suggest an interval of unstable frequencies. Our analysis generalizes the relevant observations for arbitrary combinations of Laplacian prefactor b and nonlinearity power p.
Determination of amoxicillin trihydrate impurities 4-hydroxyphenylglycine (4-HPG) and 6-Aminopenicylanic acid (6-APA) by means of ultraviolet spectroscopy
Authors: Ergin M F , Yasa Hasniye 
Published: May 2022

AbstractAmoxicillin is one of the broad-spectrumβ-lactam antibiotics widely used in the treatment of many diseases. It is inevitable that 4-hydroxyphenylglycine (4-HPG) and 6-Aminopenicylanic acid (6-APA), which are used during the production of this antibiotic, are incorporated into the molecular lattice of the product as impurities. Today, many expensive methods and chemical devices are used for the purification of Amoxicillin by determining 6-APA and 4-HPG, which are defined as impurities. In this study, it was aimed to develop a fast, simple, and specific UV-spectrophotometric method for the determination of 4-HPG and 6-APA. Another aim of this article is to cause as little harm as possible to the environment and human health by using as few chemicals as possible throughout the study. In this study, all attempts to determine 6-APA and 4-HPG, which are impurities in the production of amoxicillin, were carried out with the help of a UV/VIS spectrophotometer. Also, Four different concentrations of NaOH were used as a solvent for each impurity. UV spectra of 4-HPG and 6-APA concentrations between 210 and 400 nm were measured. In the literature, the UV spectrum of 4-HPG has been revealed for the first time in this study and examined in detail. The UV spectrum of 4-HPG was characterized in 3 regions. Again, the response of 6-APA to different NaOH concentrations was demonstrated for the first time in this study. It was determined that the peaks of 6-APA dissolved in NaOH shifted from 222 nm to 227 nm depending on the concentration amount. In addition, it is an ideal green procedure that makes a difference in the literature, as the study is carried out for the control and determination of impurities without the use of any organic solvents or chemicals harmful to the environment.
Effect of thermal deformation and Nb element action on the organization and performance of steel
Authors: Chen Longhai , Li Changrong , Wei Jiajia 
Published: May 2022

Abstract
The influences of Nb element and hot deformation on the strength of steels were systematically investigated. The microstructures and mechanical properties of the steels are determined through optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and tensile tests. The nanometer sized carbide particles precipitated in the grain boundary are attributed mainly to severe deformation at high temperature. Of the two steels with different content of Nb element and deformation, the strength of 2#steel is more lager due to more content of Nb can form more precipitates to limit grains growth. Furthermore, the results also shown that adding Nb can refine the microstructure of the steel and effectively improve the mechanical properties, but only thermal deformation has no obvious effect on the improvement of the properties of the steel.
Effects of hybrid polyethylene terephthalate fibre and fly ash on mechanical properties of concrete
Authors: Nkomo N Z , Masu L M , Nziu P K 
Published: May 2022

Abstract
Cracked concrete is a problem due to several factors such as poor maintenance, insufficient reinforcement or steel corrosion leading to crack propagation. There is a need to increase the load-bearing capacity of concrete and increase its life span. The use of waste polyethylene terephthalate fibres and fly ash in a hybrid concrete composite dramatically alleviates the problem of crack propagation and failure sustainably. This study aimed to optimize a waste polyethylene terephthalate fibre/fly ash hybrid cement composite. The concrete test specimens were fabricated using polyethylene terephthalate fibres and fly ash following a full factorial experimental design. The developed specimens were then tested to ascertain their workability and material strength properties. The combined effect of fibre addition and fly ash showed a general decreasing slump value for all quantities of fly ash content. The combined optimum compressive strength for fibre and fly ash was at 0.5% and 15%, respectively, with a strength of 15.54 N mm−2. The optimum split tensile strength of 2.79 N mm−2 was realised at 0.5% fibre and 20% fly ash mass fractions. The optimum flexural strength for fibre and fly ash mass fractions was obtained at 0.5% and 30%, respectively. The trend observed by the rebound number followed that of the compressive strength. However, the non-destructive rebound hammer method gave significantly lower strength values than the destructive test method.
An ecosystem-based natural capital evaluation framework that combines environmental and socio-economic implications of offshore renewable energy developments
Authors: Trifonova Neda , Scott Beth , Griffin Robert , Pennock Shona , Jeffrey Henry 
Published: May 2022

Abstract
There is about to be an abrupt step-change in the use of coastal seas around the globe, specifically by the addition of large-scale offshore renewable energy (ORE) developments to combat climate change. Developing this sustainable energy supply will require trade-offs between both direct and indirect environmental effects, as well as spatial conflicts with marine uses like shipping, fishing, and recreation. However, the nexus between drivers, such as changes in the bio-physical environment from the introduction of structures and extraction of energy, and the consequent impacts on ecosystem services delivery and natural capital assets is poorly understood and rarely considered through a whole ecosystem perspective. Future marine planning needs to assess these changes as part of national policy level assessments but also to inform practitioners about the benefits and trade-offs between different uses of natural resources when making decisions to balance environmental and energy sustainability and socio-economic impacts. To address this shortfall, we propose an ecosystem-based natural capital evaluation framework that builds on a dynamic Bayesian modelling approach which accounts for the multiplicity of interactions between physical (e.g. bottom temperature), biological (e.g. net primary production) indicators and anthropogenic marine use (i.e. fishing) and their changes across space and over time. The proposed assessment framework measures ecosystem change, changes in ecosystem goods and services and changes in socio-economic value in response to ORE deployment scenarios as well as climate change, to provide objective information for decision processes seeking to integrate new uses into our marine ecosystems. Such a framework has the potential of exploring the likely outcomes in the same metrics (both ecological and socio-economic) from alternative management and climate scenarios, such that objective judgements and decisions can be made, as to how to balance the benefits and trade-offs between a range of marine uses to deliver long-term environmental sustainability, economic benefits, and social welfare.
Parametric analysis on drilling of aluminium alloy hybrid composites reinforced with SIC/WC
Authors: Babu S Senthil , Dhanasekaran C , Anbuchezhiyan G , Palani Kumaran 
Published: May 2022

Abstract
Aluminium alloy (Al7075) based hybrid metal matrix composites reinforced with Silicon carbide (SiC) and Tungsten carbide (WC), at 5 wt% each are considered for this investigation, which are developed by stir casting methodology. Material characteristic analysis both at micro and macro (Tensile strength and micro hardness) level were performed. This investigation is further progressed with drilling of the composites using titanium aluminium nitride coated carbide drill (5mm diameter) for varied point angle, feed rate and drill speed. The responses such as thrust force, surface roughness and roundness error were investigated by adopting Response Surface Methodology (RSM). Multiple linear regression (MLR) is developed along with Artificial Neural Networks (ANN) model for predicting the outputs. Scanning Electron Microscope (SEM) image reveals the uniform distribution of ceramic particles in matrix which ascertains enhanced mechanical properties. The parameters such as feed rate and point angle are found to have significant influence during drilling process. The roundness error is found higher with higher point angle which is due to the wider cutting edges in the drill bit. For unconstrained multi-objective optimization, the optimal condition obtained are 128°- point angle, 0.05 mm rev−1 feed rate and 1000 rpm drill speed. For constrained optimization (roundness error ≤0.05 mm), optimal conditions are 118° point angle, 0.05 mm rev−1 feed rate and 1000 rpm drill speed.
Nonexistence and parameter range estimates for convolution differential equations
Authors: Goodrich Christopher 
Published: May 2022

We consider nonlocal differential equations with convolution coefficients of the form

−
M

(

(

a
∗

u
q

)

(
1
)

)

u
(
t
)
=
λ
f

(

t
,
u
(
t
)

)

,
t
∈
(
0
,
1
)
,

\begin{equation} -M\Big (\big (a*u^q\big )(1)\Big )u(t)=\lambda f\big (t,u(t)\big ),t\in (0,1),\notag \end{equation}

and we demonstrate an explicit range of

λ
\lambda

for which this problem, subject to given boundary data, will not admit a nontrivial positive solution; if

a
≡
1

a\equiv 1

, then the model case

−
M

(

‖
u

‖

L
q

(
0
,
1
)

q

)

u
(
t
)
=
λ
f

(

t
,
u
(
t
)

)

,
t
∈
(
0
,
1
)

\begin{equation} -M\Big (\Vert u\Vert _{L^q(0,1)}^{q}\Big )u(t)=\lambda f\big (t,u(t)\big ),t\in (0,1)\notag \end{equation}

is obtained. The range of

λ
\lambda

is calculable in terms of initial data, and our results allow for a variety of kernels,

a
a

, to be utilized, including, for example, those leading to a fractional integral coefficient of Riemann-Liouville type. Two examples are provided in order to illustrate the application of the result.
The role of pre-participation cardiac evaluation in the management of an athlete with premature ventricular contraction-induced cardiomyopathy: a case report
Authors: Norouzi Javad , Papadakis Michael , Akbarnejad Ali , Anvari Mehdi 
Published: May 2022

Abstract

Background
Premature ventricular contractions (PVCs) are commonly observed during pre-participation cardiac screening in elite athletes. There is an ongoing debate about the clinical significance of PVCs in athletes and whether burden, morphology, or both should be used to differentiate benign PVCs from PVCs suggestive of cardiac disease.

Case summary
A 28-year-old male athlete was evaluated as part of the pre-participation screening programme. He was asymptomatic, without specific cardiac signs and symptoms. A 12-lead electrocardiogram showed bigeminy PVCs with infundibular morphology and left ventricular outflow tract origin. Left ventricular dilatation and systolic dysfunction without valvular lesions was detected on echocardiography. Cardiac magnetic resonance imaging showed biventricular dilatation and dysfunction without evidence of myocardial fibrosis or fatty infiltration. A 48 h Holter monitoring showed 75191 PVCs (35% of total beats). Radiofrequency ablation was performed, and post-ablation assessments showed no PVCs with normalized ventricular function and dimension.

Discussion
This case demonstrated that a high PVC burden of common morphology does not also represent a benign finding and requires a comprehensive evaluation to rule out any pathological condition. Furthermore, the present case highlights the critical role of pre-participation cardiac evaluation in identifying cardiac disease in asymptomatic athletes.