bluuebunny/crossref_metadata_2025 huggingface dataset:
Finitely generated subgroups of branch groups and subdirect products of just infinite groups
Authors: Grigorchuk R. I. , Leemann P.-H. , Nagnibeda T. V.
Published: February 2021

The aim of this paper is to describe the structure of finitely generated subgroups of a family of branch groups containing the first Grigorchuk group and the Gupta–Sidki

-group. We then use this to show that all the groups in this family are subgroup separable (LERF).

These results are obtained as a corollary of a more general structural statement on subdirect products of just infinite groups.
Dementia risk reduction in practice: the knowledge, opinions and perspectives of Australian healthcare providers
Authors: Zheng Lidan , Godbee Kali , Steiner Genevieve Z. , Daylight Gail , Ee Carolyn , Hill Thi Yen , Hohenberg Mark I. , Lautenschlager Nicola T. , McDonald Keith , Pond Dimity , Radford Kylie , Anstey Kaarin J. , Peters Ruth
Published: February 2021

This study examined Australian primary healthcare providers’ knowledge about dementia risk factors and risk reduction and their perspectives on barriers and enablers to risk reduction in practice. Primary healthcare providers were recruited through Primary Health Networks across Australia (n = 51). Participants completed an online survey that consisted of fixed-responses and free-text components to assess their knowledge, attitudes and current practices relating to dementia risk factors and risk reduction techniques. The results showed that Australian primary healthcare providers have good knowledge about the modifiable risk factors for dementia; however, face several barriers to working with patients to reduce dementia risk. Commonly reported barriers included low patient motivation and healthcare system level limitations. The most commonly reported recommendations to helping primary healthcare providers to work with patients to reduce dementia risk included increasing resources and improving dementia awareness and messaging. While the results need to be interpreted in the context of the limitations of this study, we conclude that collaborative efforts between researchers, clinicians, policy makers and the media are needed to support the uptake of risk reduction activities in primary care settings.
Linking decomposition rates of soil organic amendments to their chemical composition
Authors: Baldock J. A. , Creamer C. , Szarvas S. , McGowan J. , Carter T. , Farrell M.
Published: February 2021

The stock of organic carbon contained within a soil represents the balance between inputs and losses. Inputs are defined by the ability of vegetation to capture and retain carbon dioxide, effects that management practices have on the proportion of captured carbon that is added to soil and the application organic amendments. The proportion of organic amendment carbon retained is defined by its rate of mineralisation. In this study, the rate of carbon mineralisation from 85 different potential soil organic amendments (composts, manures, plant residues and biosolids) was quantified under controlled environmental conditions over a 547 day incubation period. The composition of each organic amendment was quantified using nuclear magnetic resonance and mid- and near-infrared spectroscopies. Cumulative mineralisation of organic carbon from the amendments was fitted to a two-pool exponential model. Multivariate chemometric algorithms were derived to allow the size of the fast and slow cycling pools of carbon to be predicted from the acquired spectroscopic data. However, the fast and slow decomposition rate constants could not be predicted suggesting that prediction of the residence time of organic amendment carbon in soil would likely require additional information related to soil type, environmental conditions, and management practices in use at the site of application.
Language and cultural cognition
Authors: Abdel-Raheem Ahmed , Goubaa Mouna
Published: February 2021

In this paper, we analyze a large-scale corpus of Arab cartoons to measure the correspondence between grammatical gender in Arabic and personified gender in images. The results show that the effect is very strong for males (a near-perfect relationship between the two, grammatical and visual depiction), but the reverse is the case for females (the grammatical description is almost the opposite in perceived meaning of the graphical depiction). It can be a substantive cartoon effect. That is, there is more ambiguity in images depicting females due to some implicit cultural effect (i.e., males/gendered maleness dominates even in the text in ‘male-centric’ cultures). We look at the implications of this androcentric behavior for understanding the complex set of relationships linking language, thought, and culture. Such research will aid both gender studies and cognition scholarship based on multimodal stimuli.
Regularisation, optimisation, subregularity
Authors: Valkonen T
Published: February 2021

Regularisation theory in Banach spaces, and non-norm-squared regularisation even in finite dimensions, generally relies upon Bregman divergences to replace norm convergence. This is comparable to the extension of first-order optimisation methods to Banach spaces. Bregman divergences can, however, be somewhat suboptimal in terms of descriptiveness. Using the concept of (strong) metric subregularity, previously used to prove the fast local convergence of optimisation methods, we show norm convergence in Banach spaces and for non-norm-squared regularisation. For problems such as total variation regularised image reconstruction, the metric subregularity reduces to a geometric condition on the ground truth: flat areas in the ground truth have to compensate for the fidelity term not having second-order growth within the kernel of the forward operator. Our approach to proving such regularisation results is based on optimisation formulations of inverse problems. As a side result of the regularisation theory that we develop, we provide regularisation complexity results for optimisation methods: how many steps N

δ
of the algorithm do we have to take for the approximate solutions to converge as the corruption level δ ↘ 0?
A compact antipodal Vivaldi antenna with metamaterial half-lens for beam control
Authors: Cheng Houyuan , Yang Dong , Hua Lina , Wang Youcheng , Yang Helin , Wu Jiong , Li Yujun
Published: February 2021

A compact antipodal Vivaldi antenna (AVA) with metamaterial half-lens (MHL) for beam control is proposed. The proposed AVA has three different beam forms in the operating frequency band, including end beam from 3 GHz to 9 GHz, beam splitting at 12.2 GHz, and

30
∘

beam deflection at 13 GHz. Furthermore, it can perform

18
∘

beam scanning by adjusting operating frequency from 12.7 GHz to 13.5 GHz. The simulation indicates that the proposed AVA has a −10 dB impedance bandwidth of 143.6% (2.3–14.0 GHz) and a −3 dB gain bandwidth of 100% (4.5–13.5 GHz), which is consistent with the experimental results. Besides, the gain of the proposed AVA has an improvement of about 2 dB in the working band. As a new method to control the beam, the loading of MHL realizes the design of a small size and multi-function antenna, which can be widely used in wireless communication systems.
Stochastic resonance in synapse-mimicking ferroelectric organic field-effect transistor
Authors: Matsuoka Ayumi , Suzuki Yoshiharu , Kanki Teruo , Asakawa Naoki
Published: February 2021

Ferroelectric organic field-effect transistors (FE-OFETs) are fabricated to implement the functions of a neural synapse, including one-directional signal transmission and synaptic plasticity. Stochastic resonance (SR) experiments are conducted with FE-OFETs that use regioregular poly(3-hexylthiophene-2,5-diyl) as the semiconductor layer and poly(vinylidene fluoride-co-hexafluoropropylene) as the insulator layer. The input–output correlation is observed to increase as the external noise intensity rises, with a cutoff frequency of 1 Hz, demonstrating the experimental occurrence of SR in the fabricated FE-OFETs. Furthermore, vibrational resonance experiments are performed to clarify the frequency-dependence of the SR behavior. The peak input–output correlation shifts toward higher amplitudes of a secondary sine wave that is applied instead of external noise as the frequency of the input signal rises from

f

signal

= 0.5–1 Hz. The FE-OFETs exhibit more adaptive behavior than paraelectric OFETs, with a threshold voltage that changes dynamically according to the frequency characteristics of the input signal and/or external noise. Furthermore,the immediate response to abrupt environmental changes via the SR phenomenon and flexible behavior based on past experience via hysteresis effects can be implemented by a single FE-OFET element.
Magnetic properties of bulk nanocrystalline cobalt ferrite obtained by high-pressure field assisted sintering
Authors: Baldini Angelica , Petrecca Michele , Sangregorio Claudio , Anselmi-Tamburini Umberto
Published: February 2021

We present here an investigation aimed at exploring the role of the microstructure on the magnetic properties of nanostructured cobalt ferrite. Bulk, almost fully dense, nanograined ferrites have been obtained starting from nanopowders prepared by a simple, inexpensive, water-based, modified Pechini method. This synthesis yielded largely aggregated, pure single-phase cobalt ferrite nanoparticles of ca. 35 nm average size, which have been then densified by high-pressure field-assisted sintering. Different sintering conditions (pressure up to 650 MPa and temperature up to 800 °C) and procedures have been used on both as-prepared and milled nanopowders in order to obtain materials with a spectrum of complex microstructures. In all cases, the sintering process did not produce any change in the phase composition. At the same time, using a high uniaxial pressure in combination with relatively low sintering temperatures and times, allowed for obtaining a high degree of densification while preserving the nanometric size of the crystallites. Moreover, we observed that in the densified materials the best magnetic properties are not necessarily associated with a more uniform microstructure, but rather arise from a delicate balance between moderate aggregation, grain size and high density.
First-principles study of electronic structures and elasticity of Al2Fe3Si3
Authors: Hou Zhufeng , Takagiwa Yoshiki , Shinohara Yoshikazu , Xu Yibin , Tsuda Koji
Published: February 2021

Al2Fe3Si3 intermetallic compound shows promising application in low-cost and non-toxic thermoelectric device because of its relatively high power factor of ∼700 μW m−1 K−2 at 400 K. Herein we performed the first-principles calculations with the projector augmented-wave (PAW) method to study the formation energies, elastic constants, electronic structures, and electronic transport properties of Al2Fe3Si3. We discussed the thermodynamical stability of Al2Fe3Si3 against other ternary crystalline compounds in Al–Fe–Si phase. The band gap of Al2Fe3Si3 was particularly examined using the semilocal and hybrid functionals and the on-site Hubbard correction, which were also applied to β-FeSi2 to calibrate the prediction reliability of our employed computational methods. Our calculations show that Al2Fe3Si3 is a narrow-gap semiconductor. The semilocal functional within generalized gradient approximation (GGA) shows an exceptional agreement between the predicted band gap of Al2Fe3Si3 and the available experiment data, which is in contrast to the typical trend and rationally understood through a comprehensive comparison. We found that both HSE06 and PBE0 hybrid functionals with a standard setup overestimated the band gaps of Al2Fe3Si3 and β-FeSi2 too much. The underlying reasons may be ascribed to a large electronic screening, which arises from the unique characteristics of Fe 3d states appearing in both sides of band gaps of Al2Fe3Si3 and β-FeSi2, and to a reduced delocalization error thanks to the covalent Fe–Si and Si–Si bonding nature. The chemical bonding and elasticity of Al2Fe3Si3 were compared with those of β-FeSi2 and FeAl2. In Al2Fe3Si3 the Fe–Al bonding is more ionic and the Fe–Si bonding is more covalent. The elastic moduli of Al2Fe3Si3 are comparable to those of β-FeSi2 and larger than those of FeAl2. Our calculation results indicate that the mechanical strength of Al2Fe3Si3 could be strong enough for the practical application in thermoelectric device.
The3He nuclear magnetic relaxation in nematically ordered Al2O3 aerogels: effects of 4He and nitrogen pre-plating
Authors: Stanislavovas A , Kuzmin V , Safiullin K , Alakshin E , Klochkov A , Kutuzov M , Tagirov M
Published: February 2021

The results of 3He gas pulsed NMR spin–lattice relaxation study in high-porosity (84.9%–97.9%) nematically ordered Al2O3 aerogels at 1.5 and 4.2 K are presented. The linear dependence of T
1 on gas pressure is observed in aerogels that are pre-plated by helium-4. Nitrogen pre-plating prior to helium-4 pre-plating weakly decreases the 3He gas spin–lattice relaxation rate. A few possible mechanisms plausibly involved in 3He nuclear magnetic relaxation in aerogels are considered. The suggested nuclear spin–lattice relaxation model due to some magnetically ‘dirty’ aerogel fibers allows to estimate the effective mean free path of 3He atoms in aerogel.
Transition to thermal equilibrium in a crystal subjected to instantaneous deformation
Authors: Krivtsov A M , Murachev A S
Published: February 2021

An adiabatic transition between two equilibrium states corresponding to different stiffnesses in an infinite chain of particles is studied. Initially, the particles have random displacements and random velocities corresponding to uniform initial temperature distributions. An instantaneous change in the parameters of the chain initiates a transitional process. Analytical expressions for the chain temperature as a function of time are obtained from statistical analysis of the dynamic equations. It is shown that the transition process is oscillatory and that the temperature converges non-monotonically to a new equilibrium state, in accordance with what is usually unexpected for thermal processes. The analytical results are supplemented by numerical simulations.
A novel robot-assisted electrical impedance scanning system for subsurface object detection
Authors: Cheng Zhuoqi , Savarimuthu Thiusius Rajeeth
Published: February 2021

Submerged elements, such as cracks inside concrete material or hidden pathological tissue, can potentially threaten safety and health. Thus, the detection of abnormal objects internally is of importance and frequently required. In this study, we propose a novel electrical impedance measurement method with the assistance of a robotic system. Specifically, the proposed measurement method is able to perform subsurface object detection effectively, noninvasively, flexibly and autonomously. The measurement system is developed based on a tripolar impedance sensing configuration. Specifically, a current-source electrode and a voltage-measurement electrode are attached to different robots, and directed to a series of preset positions on the object’s surface. By injecting current into the object and measuring voltages around the current source, the apparent resistivity of the internal structure of the object can be calculated using the proposed algorithm. The related circuit hardware and autonomous control strategy are developed. Subsequently, the proposed system is evaluated through a series of water tank experiments. The experimental results demonstrate that the proposed system can detect a subsurface heterogeneous object effectively and efficiently. In addition, the reconstructed results allow us to discriminate the location of the subsurface object with about 90% accuracy.
Antiviral application of colloidal and immobilized silver nanoparticles
Authors: Bharti Sharda , Mukherji Soumyo , Mukherji Suparna
Published: February 2021

This study explored the application of colloidal and immobilized silver nanoparticles (AgNPs) for inactivation of bacteriophages. Coliphages that are commonly used as indicators for enteric viruses, were used in this study. Colloidal AgNPs were synthesized via a chemical reduction approach using sodium borohydride as reducing agent and trisodium citrate as stabilizing agent. AgNP-immobilized glass substrate was prepared by immobilizing AgNPs on amine-functionalized glass substrate by post-immobilization method. The AgNP-immobilized glass substrate was also tested so as to minimize the release of AgNPs in the treated water. The characterization of AgNPs and the AgNP-immobilized glass surface was done using field emission gun-transmission electron microscopy and scanning electron microscopy. Studies conducted with varying concentrations of colloidal AgNPs displayed good antiviral activity for MS2 and T4 bacteriophage. Colloidal AgNPs at a dose of 60μg ml−1could completely inactivate MS2 and T4 bacteriophage within 30 and 50 min with an initial concentration of 103PFU ml−1. Contaminated water (100 ml) in an unstirred batch reactor with an initial bacteriophage concentration of 103PFU ml−1could be inactivated by the AgNP-immobilized glass substrate (1 cm × 1 cm, containing 3.7μg cm−2silver) suspended centrally in the batch reactor. Complete 3-Log bacteriophage inactivation was achieved within 70 and 80 min for MS2 and T4 bacteriophage, respectively, while the aqueous silver concentration was less than 25μg l−1. This is significantly lower than the recommended standard for silver in drinking water (i.e. 100μg l−1, US EPA). Thus, AgNP-immobilized glass may have good potential for generating virus-free drinking water.
Lead halide perovskite quantum dots based liquid scintillator for x-ray detection
Authors: Xu Qiang , Huang Jie , Liu Jun , Wang Juan , Zhou Shuai , Wang Xiang , Nie Jing , Guo Yong , Ouyang Xiaoping
Published: February 2021

Lead halide quantum dots (QDs) have unique optical properties such as a tunable wavelength, narrow band, and high quantum efficiency, and have been used in optoelectronics such as light-emitting diode device, and photodetector. Recently, solution-processed perovskite has also attracted great attention for high sensitivity x-ray detector. Here, we have investigated the scintillation performances of Pb halide perovskite QDs solution. Both CH3NH3PbBr3 and CsPbBr3 QDs liquid scintillator exhibits the scintillation performances such as the linear relationship with the irradiation dose rate in a wide range, high radiation hardness, thermal stability, and fast counting speed. The scintillation performances of these liquid perovskite QDs solution provide a promising potential application for indirect radiation applications including fast gamma-ray counter and wide range dosimeter.
Ultrahigh hydrogen storage capacity of holey graphyne
Authors: Gao Yan , Zhang Huanian , Pan Hongzhe , Li Qingfang , Zhao Jijun
Published: February 2021

Holey graphyne (HGY), a novel two-dimensional (2D) single-crystalline carbon allotrope, was recently synthesized by Castro–Stephens coupling reaction. The naturally existing uniform periodic holes in the 2D carbon–carbon network demonstrate its promising potential in energy storage. Herein, we conduct density functional theory (DFT) calculation and ab initio molecular dynamics simulations (AIMD) to predict the H storage properties of a single-layer HGY sheet modified by Li metal atoms. The DFT calculations demonstrate that Li atoms can bind strongly to the HGY sheet without forming clusters, and each Li atom can anchor four H2 molecules with an average adsorption energy of about −0.22 eV/H2. The largest H storage capacity of the doped HGY sheet can reach as high as 12.8 wt%, showing that the Li/HGY complex is an ideal H storage material at ambient conditions. In addition, we investigate the polarization mechanism of the storage media and find that the polarization originates from the electric field induced by both the ionic Li atoms and the weak polarized H2 molecules. Finally, the desorption mechanism of the adsorbed H2 molecules is thoroughly investigated using a kinetic AIMD method.
Rational design of hollow mesoporous titania nanoparticles loaded with curcumin for UV-controlled release and targeted drug delivery
Authors: Mai Zhuoxian , Chen Jiali , Cao Qingyun , Hu Yang , Dong Xianming , Zhang Hongwu , Huang Wenhua , Zhou Wuyi
Published: February 2021

Curcumin (Cur), appeared to provide huge potential in biomedical application. However, its therapeutic efficacy was greatly limited as the result of poor solubility and instability. To address these limitations, we create a new type of hollow mesoporous titania nanoparticle (HMTN) to encapsulate Cur. HMTN was decorated with a layer of hydrophilic polyethylenimine (PEI), which controlled the release rate of Cur inside the pore due to its dendritic structure. Combined with the folic acid (FA) mediated targeting effect, the potential multifunctional Cur loaded titania nanoparticle (Cur-FA-PEI-HMTN) showed excellent biocompatibility and bioavailability, as well as the UV-responsive drug release properties. The operating parameters to prepare hollow structure were studied and the Cur-FA-PEI-HMTN nanosystem had been fully characterized by Brunauer–Emmet–Teller, Fourier transform infrared spectroscopy, transmission electron microscope, thermal gravity analysis, differential thermal analysis, x-ray diffraction, dynamic light scattering and zeta potential. In addition, the hemolytic test, as well as CCK8, flow cytometry, Hoechst 33342 staining experiment, were carried out to confirm the low cytotoxity and high biocompatibility. The confocal microscopy analysis results also revealed the increasing uptake of Cur@FA-PEI-HMTN by MCF-7 cells. The synthesized nanoparticles displayed great potential as drug nanovehicles with high biocompatibility.
Effect of friction on a hula hoop
Authors: Cross Rod
Published: February 2021

The physics of a hula hoop is determined primarily by the effect of the centripetal force acting on the hoop. However, the friction force on the hoop also plays a role. A simple experiment is described showing how an increase in the friction coefficient can help to prevent the hoop falling.
Radiative characterization of supersonic jets and shocks in a laser-plasma experiment
Authors: Bohlin H , Brack F-E , Cervenak M , Chodukowski T , Cikhardt J , Dostál J , Dudžák R , Hubner J , Huo W , Jelinek S , Klír D , Kroll F , Krupka M , Krůs M , Pisarczyk T , Rusiniak Z , Schramm U , Nguyen-Bui T-H , Weber S , Zaraś-Szydłowska A , Zeil K , Kumar D , Schlegel T , Tikhonchuk V
Published: February 2021

The interaction of supersonic laser-generated plasma jets with a secondary gas target was studied experimentally. The plasma parameters of the jet, and the resulting shock, were characterized using a combination of multi-frame interferometry/shadowgraphy, and x-ray diagnostics, allowing for a detailed study of their structure and evolution. The velocity was obtained with an x-ray streak camera, and filtered x-ray pinhole imaging was used to infer the electron temperature of the jet and shock. The topology of the ambient plasma density was found to have a significant effect on the jet and shock formation, as well as on their radiation characteristics. The experimental results were compared with radiation hydrodynamic simulations, thereby providing further insights into the underlying physical processes of the jet and shock formation and evolution.
Modified Schwarzschild metric from a unitary accelerating mirror analog
Authors: Good Michael R R , Linder Eric V
Published: February 2021

We present a modified Schwarzschild solution for a model of evaporation of a black hole with information preservation. By drawing a direct analogy to the quantum pure accelerating mirror (dynamical Casimir effect of a 1D horizon), we derive a Schwarzschild metric with not only the usual Schwarzschild radius but an additional length scale related to the Planck length. The black hole has thermal particle production that leads to complete evaporation of the black hole, resulting in non-divergent entanglement entropy, Page curve turn-over, and an asymptotic quantum pure state with no information loss.
Quasi-exact solution of the Dirac equation on curved space-time with Coulomb scalar and vector potentials and Mie-type tensor potential with pseudo-spin and spin symmetries
Authors: de Oliveira M D , Schmidt Alexandre G M
Published: February 2021

In this paper we solve the Dirac equation with the Coulomb scalar U(r) and vector V(r) potentials and type-Mie tensor potential in curved space-time whose metric is of type

ds

2

=

(
1
+

α

2

U
(
r
)
)

2

(

dt

2

−

dr

2

)
−

r

2

d

θ

2

−

r

2

sin

2

θ
d

ϕ

2

with spherical symmetry. For this we consider two types of symmetry in the system, first spin symmetry with V(r) = U(r) and then with pseudo-spin symmetry V(r) = − U(r). In both cases we have a tensor potential A(r) that coupling through the electromagnetic field A

μ
= (V(r), cA(r), 0, 0). We find, quasi-exactly, the Dirac spinor and the energy spectrum of the system, and we sketch the probability densities and some energy spectra.
Light manipulation in three-dimensional photonic integrated circuits using vertically inserted metasurfaces
Authors: Wu Lin , Zhang Ziyang
Published: February 2021

The hybrid integration of silicon metasurfaces, in forms of insertable thin-film elements, into a multilayer polymer waveguide platform is introduced. Owing to the wavelength comparable thickness and high efficiency of the dielectric metasurfaces, the designed devices can manipulate beams in a relatively short distance with low insertion loss. They can also realize functions critical for three-dimensional (3D) photonic integrated circuits (PICs) that are difficult for conventional micro-optic elements. The designs of several key photonic components are presented in this work as proof-of-concept. Specifically, three applications based on the proposed platform are demonstrated numerically, including on-chip beam collimation, spatial mode (de)multiplexing, and focusing vertical out-coupling. These functionalities can be realized within a short propagating length. This work presents a theoretical study on the design principles and performances of the proposed devices, which can be implemented by adopting the existed technology of inserting classic thin-film elements into photonic chips in the near future. The results suggest a novel and general path for optical signal manipulations within the 3D photonic chips and may prove useful in the design of transceiver devices for optical communication, optical sensor chips, compact chips for optical computation, etc.
Evaluation of tritium production rate in a blanket mock-up using a compact fusion neutron source
Authors: Mukai Keisuke , Ogino Yasuyuki , Kobayashi Makoto I. , Mahmoud Bakr , Yagi Juro , Ogawa Kunihiro , Isobe Mitsutaka , Konishi Satoshi
Published: February 2021

We report a neutronics study of a blanket mock-up using a discharge-type compact fusion neutron source. Deuterium–deuterium fusion neutrons were irradiated to the mock-ups composed of tritium breeder and neutron reflector/moderator. The tritium production rate (TPR) per source neutron was measured by a single-crystal diamond detector with a 6Li-enriched lithium fluoride film convertor after the calibration process. Despite the low neutron yield, energetic alpha and triton particles via 6Li(n, t)α neutron capture as well as 12C via elastic scattering were successfully detected by the SDD with high signal to noise ratios. The TPRs were experimentally evaluated with errors of 8.4%–8.5% at the 1σ level at the positions with high thermal neutron fluxes where the errors were dominantly introduced by uncertainties in the monitoring of the neutron production rate. The calculated to experimental (C/E) values of TPR were evaluated to be 0.91–1.27 (FENDL-2.1) and 0.94–1.28 (FENDL-3.1). As the neutron source can generate 14 MeV neutrons using a mixed gas of deuterium and tritium, this approach provides more opportunities for blanket neutronics experiments.
Geomagnetic induced current modelling and analysis on high voltage power system
Authors: Khurshid Z M , Ab Aziz N F , Ab Kadir M Z A , Rhazali Z A
Published: February 2021

Geomagnetically induced current (GIC) has become a significant concern that can affect the electrical power grid by causing a half-cycle saturation of power transformers. This saturation leads to an increase in even and odd harmonic distortions and reactive power losses of transformers, which may consequence in improperly triggering relays, tripping reactive power (VAR) compensators and shunt capacitor banks. Also, these reactive losses, harmonic, and the stray flux resulted due to this saturation may lead to overheating windings and cores of power transformers and generators and hence blackout. In this paper, GIC analysis has been conducted on a modified IEEE-18 bus test system by using Power System Simulator for Engineering (PSS/E) and Power System Computer-Aided (PSCAD/EMTDC) software. The simulation results have been obtained by considering a worst-case scenario of geomagnetic disturbance (GMD) by applying uniform induced electric fields with values of 10 V/km and 20 V/km at different directions with and without GIC blocking devices. Also, the impact of grounding resistances of the substations on calculated GIC due same mentioned induced fields has been investigated. The results show that the highest total reactive power losses across the system are obtained due to related induced electric fields at 120° and 300° storm angle. After the connection of GIC blocking devices to the substations, these reactive losses have drastically reduced. In addition, simulation results of the same test system by using PSCAD platform are obtained to investigate hysteresis and harmonic results during system operation and the presence of GIC.
Image Processing Based Forest Fire Detection using Infrared Camera
Authors: Ya’acob Norsuzila , Syamirza Mohd Najib Mohammad , Tajudin Noraisyah , Laily Yusof Azita , Kassim Murizah
Published: February 2021

When time goes by, human beings are advancing in technology, artificial and natural disasters are drastically increasing. The forest fire is one of the hazards. Forest fire incinerates trees that provide us with oxygen and if it is not detected early, it is very elusive to stop a forest fire from continue burns. The project’s objective is to capture infrared image of forest fire detection using the appropriate camera, detect fire with RGB and YCbCr colour model to isolate fire pixels from the background and separate luminance and chrominance from the original image, and filter image using MATLAB Analyzer to process images. The method is tested on a selected image, which captured by the camera that contains fire. Next method is used for calculating and analysing the fire image, which to differentiate between fire detection or false detection. Other method is used to process the fire image, which the image will compute and shown in terminal nodes and graphs by using Wavelet Analyzer 5.0. The results of this system are achieved fire detection and obtain data for the fire images.
A perfect prognosis downscaling methodology for seasonal prediction of local-scale wind speeds
Authors: Ramon Jaume , Lledó Llorenç , Bretonnière Pierre-Antoine , Samsó Margarida , Doblas-Reyes Francisco J
Published: February 2021

This work provides a new methodology based on a statistical downscaling with a perfect prognosis approach to produce seasonal predictions of near-surface wind speeds at the local scale. Hybrid predictions combine a dynamical prediction of the four main Euro-Atlantic Teleconnections (EATC) and a multilinear statistical regression, which is fitted with observations and includes the EATC as predictors. Once generated, the skill of the hybrid predictions is assessed at 17 tall tower locations in Europe targeting the winter season. For comparative purposes, hybrid predictions have also been produced and assessed at a pan-European scale, using the ERA5 100 m wind speed as the observational reference. Overall, results indicate that hybrid predictions outperform the dynamical predictions of near-surface wind speeds, obtained from five prediction systems available through the Climate Data Store of the Copernicus Climate Change Service. The performance of a multi-system ensemble prediction has also been assessed. In all cases, the enhancement is particularly noted in northern Europe. By being more capable of anticipating local wind speed conditions in higher quality, hybrid predictions will boost the application of seasonal predictions outside the field of pure climate research.
Soil organic matter protects US maize yields and lowers crop insurance payouts under drought
Authors: Kane Daniel A , Bradford Mark A , Fuller Emma , Oldfield Emily E , Wood Stephen A
Published: February 2021

Higher levels of soil organic matter improve soil water retention, meaning they could mitigate agricultural yield losses from drought. Yet evidence to support such claims is mixed and incomplete. Using data from 12 376 county-years in the United States of America, we show that counties with higher soil organic matter are associated with greater yields, lower yield losses, and lower rates of crop insurance payouts under drought. Under severe drought, an increase of 1% soil organic matter was associated with a yield increase of 2.2 ± 0.33 Mg ha−1(32.7 bu ac−1) and a 36 ± 4.76% reduction in the mean proportion of liabilities paid. Similar, yet smaller, effects were found for less severe levels of drought and this effect was reduced as soil clay content increased. Confirmatory pathway analyses indicate that this positive association of soil organic matter and yields under drought is partially explained by positive effects of soil organic matter on available water capacity and cation exchange capacity, but that soil organic matter may be imparting yield protection via mechanisms not fully captured by those metrics. Overall, our results suggest soil organic matter predicts yield resilience at regional scales in the United States. We argue that data on soil organic matter should be used in agricultural policy and financial planning, with our analyses providing quantitative evidence of the co-benefits of soil organic matter believed fundamental to advancing soil health and carbon sequestration initiatives.
Increasing tropical cyclone intensity and potential intensity in the subtropical Atlantic around Bermuda from an ocean heat content perspective 1955–2019
Authors: Hallam Samantha , Guishard Mark , Josey Simon A , Hyder Pat , Hirschi Joel
Published: February 2021

We investigate tropical cyclone (TC) activity and intensity within a 100 km radius of Bermuda between 1955 and 2019. The results show a more easterly genesis over time and significant increasing trends in TC intensity (maximum wind speed (Vmax)) with a decadal Vmax median value increase of 30 kts from 33 to 63 kts (r= 0.94,p= 0.02), together with significant increasing August, September, October sea surface temperature (SST) of 1.1 °C (0.17 °C per decade)r= 0.4 (p< 0.01) and increasing average ocean temperature between 0.5 °C and 0.7 °C (0.08 °C–0.1 °C per decade)r= 0.3(p< 0.01) in the depth range 0–300 m. The strongest correlation is found between TC intensity and ocean temperature averaged through the top 50 m ocean layer (T50m‾)r= 0.37 (p< 0.01). We show how TC potential intensity (PI) estimates are closer to actual intensity by usingT50m‾as opposed to SST using the Hydrostation S time-series. We modify the widely used SST PI index by usingT50m‾to provide a closer estimate of the observed minimum sea level pressure (MSLP), and associated Vmax than by using SST, creating aT50m‾PI (T50m‾_PI) index. The average MSLP difference is reduced by 12 mb and proportional (r= 0.74,p< 0.01) to the SST/T50m‾temperature difference. We also suggest the index could be used over a wider area of the subtropical/tropical Atlantic where there is a shallow mixed layer depth.
Boat to bowl: resilience through network rewiring of a community-supported fishery amid the COVID-19 pandemic
Authors: Carlson Andrew K , Young Talia , Centeno Miguel A , Levin Simon A , Rubenstein Daniel I
Published: February 2021

Fisheries are coupled human–natural systems locally, regionally, and globally. However, human–nature interactions within and between adjacent and distant systems (metacouplings) are rarely studied in fisheries despite their prevalence and policy relevance. We filled this knowledge gap by using network models to identify how the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has rewired couplings and reshaped resilience of Fishadelphia, a community-supported fishery program (CSF) in New Jersey and Pennsylvania, USA. As abstractions illustrating interactions among supply-chain actors, networks are helpful for characterizing flows and assessing resilience to disturbances such as those induced by the SARS-CoV-2 pandemic. Since Fall 2018, 18 seafood (finfish and shellfish) species totaling 6273 lbs have flowed from harvesters (n = 4), to processors (n = 2), to a distributor, to retailers (n = 2), and finally to customers (n = 183). The pandemic reduced the number of seafood harvesters and processors (−50%), seafood flow quantity (−25%), species diversity in the marketplace (−67%), and species per supplier (−50%) before stopping flows in mid-March 2020, when Fishadelphia closed for 3 months. Models of network optimality indicated that the pandemic fragmented metacouplings that previously allowed multiple seafood suppliers to provide diverse products to customers. However, demand-side resilience increased through dispersed, socially distanced, efficient seafood delivery that expanded the customer base and generally increased customer satisfaction. This resilience dichotomy—wherein the post-closure network was less resilient than the pre-closure network in supply-side species diversity, but more resilient in demand-side social distancing, delivery efficiency, and customer satisfaction—has implications for rewiring networks to sustain CSFs and other local food systems amid ecological and social disturbances.
The association between maternal exposure to fine particulate matter (PM2.5) and gestational diabetes mellitus (GDM): a prospective birth cohort study in China
Authors: Chen Guimin , Sun Xiaoli , Wang Jiaqi , Dong Moran , Ye Yufeng , Liu Xin , Sun Jiufeng , Xiao Jianpeng , He Guanhao , Hu Jianxiong , Guo Lingchuan , Li Xing , Rong Zuhua , Zeng Weilin , Zhou He , Chen Dengzhou , Li Jiali , Ma Wenjun , Bartashevskyy Maksym , Wen Xiaozhong , Liu Tao
Published: February 2021

Although previous studies have proposed an association between maternal exposure to fine particulate matter (PM2.5) and the risk of gestational diabetes mellitus (GDM), such evidence remains rare. Additionally, the effects of PM2.5 on glycemic control in GDM patients are poorly known. In this study, we conducted a prospective birth cohort study in China, and aimed to investigate the association between maternal exposure to PM2.5 and the risk of GDM, identify the susceptible exposure window, and quantify the exposure-response relationships between PM2.5 and fasting glucose in GDM patients. A spatiotemporal land-use-regression model was used to estimate individual weekly PM2.5 exposure during pregnancy. A distributed lag nonlinear model incorporated with a Cox proportional hazard model was used to estimate the association between maternal exposure to PM2.5 and the risk of GDM. Among the 4174 pregnant women in our study, 1018 (24.4%) were diagnosed with GDM. Each 10 μg m−3 increment in PM2.5 exposures during the 24th gestational week was significantly associated with a higher risk of GDM [hazard ratio (HR) = 1.03, 95% CI (confidence interval): 1.01, 1.06]. Compared to the lowest quartile (Q1) of PM2.5 exposure, participants with the highest quartile (Q4) during the 21st–24th gestational weeks had a higher risk of GDM, and the strongest association was observed in the 22nd gestational week (HR = 1.15, 95%Cl: 1.02, 1.28). The mean PM2.5 exposures during the 21st–24th weeks were positively associated with fasting plasma glucose in pregnant women with GDM. Each 10 μg m−3 increase in the mean PM2.5 exposure was associated with a 0.07 mmol l−1 (95% CI: 0.04, 0.11 mmol l−1) increase in the fasting glucose level. Our findings suggest that maternal exposure to higher PM2.5 during pregnancy may increase the risk of GDM, and result in poor glycemic control among pregnant women with GDM. The 21st–24th gestational week period might be the (most)? susceptible exposure window of PM2.5.
The Biotic Integrity of Ciliwung River in West Java Under Multiple Urban Stressors
Authors: Sutjiningsih Dwita , Soeryantono Herr , Anggraheni Evi , Saleh Toha
Published: February 2021

Based on its imperviousness, most of the sub-watersheds in the lower part of Ciliwung watershed in West Java are classified as urban drainage. High imperviousness in the urban environment will cause multiple stressors among others on the discharge, water quality and habitat condition, those supposedly support the presence of macroinvertebrates. Macroinvertebrates are commonly used as markers of the biotic integrity of aquatic ecosystem. The aim of the study is to explore the extent of causal relationship between imperviousness, as trigger for the emergence of stressors on biotic integrity, which is represented by Family Biotic Index. The Family Biotic Index is considered as response variables, while imperviousness, discharge, water quality and habitat condition are as explanatory variables. Significance correlation tests among explanatory and response variables from 23 sub-watersheds of Ciliwung using Spearman Rank-order Correlation show that they are correlated. Influence of multiple urban stressors on the biotic integrity was assessed using several alternatives of multiple linear regression model, which is determined based on backward elimination procedure. The standard error of estimate ranges between 0.8563 and 0.9096 are less than standard deviation amounted 1.0876, therefore the models are acceptable for predicting the response variable, the FBI. Although they have not yet fully represented the observed FBI values, especially for the lowest and the highest one, possibly due to very limited data. This can be seen from the low value of the coefficient of determination, R2 ranging from 33,23% up to 43.86%, and from the juxtaposed between model results and the observed values.
Factors Affecting Concrete Recycling Adoption in the Construction Projects
Authors: Badraddin A K , Rahman R A , Zakaria Z , Hasan M
Published: February 2021

Recycling addresses environmental issues associated with solid waste by minimizing overall resource consumption and environmental impact. In the construction industry, concrete recycling is crucial because concrete is the most dominant waste of construction and demolition waste. However, its implementation is at a low level in numerous countries becauseconstruction managers refuse to adopt concrete recycling in practice. This study’s objective is to identify factors that are affecting decisions in adopting concrete recycling from the constructionmanagers’ perspective. To achieve this objective, open-ended interview data with constructionmanagers are analyzed. Eleven factors affecting decisions in adopting concrete recycling inure identified. The factors are recycling factories, availability of raw material, quality, cost, reliable standard, government encouragement, legally, acceptance factor, proper planning, skilled workforce, and management. This research contributes to the body of knowledge in the analysis of factors that influence the acceptance of concrete recycling from industry practitioners’ perspectives, which could help researchers and industry practitioners develop strategies to reduce the rejection of concrete recycling among construction managers. The findings of this research would help improve the success of adopting concrete recycling in the construction industry.
Optimization Techniques for Rehabilitating Water Distribution Networks
Authors: Farouk A M , Romali N S , Rahman R A , Seman M A
Published: February 2021

Water sustainability ensures clean and plentiful water for both current and future generations. Water is the core of sustainable development as it is critical for socio-economic development, healthy ecosystems, and for human survival itself. It helps companies address supply and demand issues by using water more efficiently as well as reducing the amount of water needed to manufacture their products. Maintaining water sustainability is difficult because of a high level of non-revenue water (NRW) or water losses in water distribution networks (WDN). While one of the significant causes of NRW in Malaysia is difficulties in rehabilitating WDN, studies on effective approaches for rehabilitating WDN is limited. So, it is essential to understand the optimization techniques for rehabilitating WDN. Hence, this study’s objective is to identify the different optimization techniques for rehabilitating WDN by systematically reviewing the existing literature on WDN rehabilitation. This research contributes to the body of knowledge in providing insights on optimization techniques for WDN rehabilitation, which could help researchers and industry practitioners reduce NRW and achieve water sustainability.
Research on intelligent inspection technology of distribution network based on RFID
Authors: Hu Yang , Zhang Jun , Wang Dongliang
Published: February 2021

As an important part of power system, the safe and stable operation of distribution network affects the power quality of the whole society and the reliability of power grid operation. As a technology widely used in Internet of things equipment, radio frequency identification (RFID) has the characteristics of non-contact reading and wide identification range, which is especially suitable for the working situation of patrol distribution network equipment. Based on radio frequency identification technology, non-contact two-way communication is carried out. According to the task transmitted from the workstation, the inspection results are recorded, and the field data is transmitted to the background management system through the wireless communication network. The intelligent purpose of the distribution network inspection system is realized, so as to improve the inspection efficiency and the reliability of the power grid operation.
Method for selecting location and capacity of ring station in the urban distribution network
Authors: Song Ruochen , Gu Xiaoming , Liu Hong , Wang Haojia
Published: February 2021

Aiming at the lack of a systematic research method on the distribution of ring station in the existing 10kV urban medium voltage distribution network research, a method of ensuring the location and capacity of ring station based on the weighted Voronoi diagram is proposed. First, analyze the location and capacity of ring station based on the structure of the urban medium-voltage distribution network; Second, in view of the location and capacity of the ring station of the urban medium voltage distribution network, the line investment of the upper-level to the ring station, the investment cost of the ring station, and the line investment of the lower-level to the ring station are comprehensively considered, and build the mathematical model. Third, a method of ensuring the location selection and capacity determination of ring station based on weighted Voronoi diagrams and a solution process are proposed. Finally, an example is used to verify the effectiveness and practicability of the proposed method.