bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-resolution magnetic nanoparticle temperature measurement method based on dual-frequency magnetic field excitation
Authors: Wang Shuai , Zhang Pu , Liu Wenzhong , Guo Silin , Zhang Yapeng 
Published: September 2020

Abstract
A new remote method for measuring temperature using magnetic nanoparticles (MNPs) is presented in this paper. The method involves exciting MNPs in a dual-frequency AC magnetic field, and using tunnel magnetoresistance to detect the mixing-frequency magnetization response signals. The effects of the excitation magnetic field amplitude and frequency on the temperature measurement were analyzed. Based on the relationship between the MNPs’ magnetization harmonic amplitudes and their temperature, two-harmonic and four-harmonic temperature measurement models were established. The estimated temperature was obtained by the optimized parameter estimation algorithm. The temperature error was found to be less than 0.02 K using the two-harmonic model and less than 0.015 K using the four-harmonic model.
OH molecule-involved formation of point defects in monolayer graphene
Authors: Ryu Gyeong Hee , Lee Sungwoo , Kim Jung Hwa , Lee Gun-Do , Lee Zonghoon 
Published: September 2020

Abstract
Point defects in freestanding graphene monolayers such as monovacancies (MVs) and divacancies have been investigated at atomic scale with aberration-corrected transmission electron microscopy and theoretical calculations. In general, these defects can be formed simply by the absence of individual carbon atoms and carbon bond reconstructions in the graphene lattice under electron and ion irradiation. However, in this study, we found that oxygen and hydrogen atoms can be involved in the formation of these point defects caused by the simultaneous detachment of oxygen–carbon atoms. Here we report the effect of the oxygen and hydrogen atoms on the graphene surface forming the point defects under electron beam irradiation, and their role of stabilizing other MVs when composed of 13–5 ring pairs. In addition, theoretical analysis using density functional theory calculations demonstrates that the participating atoms can form the point defects in the intermediate states and stabilize 13–5 ring pairs under electron beam irradiation.
MoS2/pentacene hybrid complementary inverter based photodetector with amplified voltage–output
Authors: Liu Fengjing , Zhang Yiwei , Wang Jiawei , Chen Yiyi , Wang Liang , Wang Gongtang , Dong Ji , Jiang Chao 
Published: September 2020

Abstract
A sensitive photodetection based on a novel hybrid CMOS inverter has been demonstrated. Unlike common photo-current type photodetectors, which convert optical signals to current, the CMOS inverter realizes voltage–output, overcoming the difficulty to monitor current signal in the range of nA. The hybrid CMOS logic inverter employs n-channel MoS2 nanosheet/perovskite heterojunction FET and p-channel organic pentacene FET in a planar architecture. In order to obtain high performance, we adopt the interdigital electrodes for the pentacene FET to enhance the current density of the p-channel, and stack perovskite on the MoS2 channel to modify the threshold voltage of the n-channel. As a result, a CMOS inverter with a voltage gain of more than ten is obtained. When VIN is around the transition voltage (−38 V), the inverter can obtain stable optical detection signal, the VOUT changes from 6 V in dark to 1 V under 633 nm light exposure. This finding indicates the potential to fabricate visible light detecting devices with voltage–output based on the inverter and may be further applicable for a photo-logic circuit.
Bayesian non-linear regression with spatial priors for noise reduction and error estimation in quantitative MRI with an application in T1 estimation
Authors: Löfstedt Tommy , Hellström Max , Bylund Mikael , Garpebring Anders 
Published: September 2020

Abstract

Purpose. To develop a method that can reduce and estimate uncertainty in quantitative MR parameter maps without the need for hand-tuning of any hyperparameters. Methods. We present an estimation method where uncertainties are reduced by incorporating information on spatial correlations between neighbouring voxels. The method is based on a Bayesian hierarchical non-linear regression model, where the parameters of interest are sampled, using Markov chain Monte Carlo (MCMC), from a high-dimensional posterior distribution with a spatial prior. The degree to which the prior affects the model is determined by an automatic hyperparameter search using an information criterion and is, therefore, free from manual user-dependent tuning. The samples obtained further provide a convenient means to obtain uncertainties in both voxels and regions. The developed method was evaluated on T
1 estimations based on the variable flip angle method. Results. The proposed method delivers noise-reduced T
1 parameter maps with associated error estimates by combining MCMC sampling, the widely applicable information criterion, and total variation-based denoising. The proposed method results in an overall decrease in estimation error when compared to conventional voxel-wise maximum likelihood estimation. However, this comes with an increased bias in some regions, predominately at tissue interfaces, as well as an increase in computational time. Conclusions. This study provides a method that generates more precise estimates compared to the conventional method, without incorporating user subjectivity, and with the added benefit of uncertainty estimation.
Towards real-time 4D radiation dosimetry on an MRI-Linac
Authors: De Deene Y , Wheatley M , Dong B , Roberts N , Jelen U , Waddington D , Liney G 
Published: September 2020

Abstract
4D radiation dosimetry using a highly radiation-sensitive polymer gel dosimeter with real-time quantitative magnetic resonance imaging (MRI) readout is presented as a technique to acquire the accumulated radiation dose distribution during image-guided radiotherapy on an MRI-Linac. Optimized T
2-weighted Turbo-Spin-Echo (TSE) scans are converted into quantitative ΔR
2 maps and subsequently to radiation dose maps.
The concept of temporal uncertainty is introduced as a metric of effective temporal resolution. A mathematical framework is presented to optimize the echo time of the TSE sequence in terms of dose resolution, and the trade-off between temporal resolution and dose resolution is discussed. The current temporal uncertainty achieved with the MAGAT gel dosimeter on a 1 T MRI-Linac is 3.8 s which is an order of magnitude better than what has been achieved until now.
The potential of real-time 4D radiation dosimetry in a theragnostic MRI-Linac is demonstrated for two scenarios: an irradiation with three coplanar beams on a head phantom and a dynamic arc treatment on a cylindrical gel phantom using a rotating couch. The dose maps acquired on the MRI-Linac are compared with a treatment plan and with dose maps acquired on a clinical 3 T MRI scanner. 3D gamma map evaluations for the different modalities are provided. While the presented method demonstrates the potential of gel dosimetry for tracking the dose delivery during radiotherapy in 4D, a shortcoming of the MAGAT gel dosimeter is a retarded dose response.
The effect of non-ideal radiofrequency pulses resulting from limitations in the specific absorption rate or B1-field inhomogeneity on the TSE acquired ΔR
2 values is analysed experimentally and by use of computational modelling with a Bloch simulator.
Effect of ferroelectric parameters variation on the characteristics of polarity controllable–ferroelectric–field-effect transistors at elevated temperatures
Authors: Pandey Priyanka , Kaur Harsupreet 
Published: September 2020

Abstract
In the present work, detailed analyses are carried out to study the impact of temperature on the device performance of a single-gated polarity-controllable–ferroelectric–field-effect transistor (PC–FE–FET). Further, the impact of unintentional variations (≤±5%) in ferroelectric (FE) material parameters are extensively investigated. Various device characteristics are studied by implementing the baseline approach. Due to the integration of an FE layer, the proposed device shows remarkable improvements in current drivability, transconductance and transconductance generation factor, and even at elevated temperatures, sub-60 subthreshold swing values are achieved in comparison to the conventional polarity-controllable–FET (PC-FET) for both n- and p-modes of operation. It is demonstrated that the PC–FE–FET shows remarkable stability towards variations in FE parameters.
Mitigating decoherence in hot electron interferometry
Authors: Clark Lewis A , Kataoka Masaya , Emary Clive 
Published: September 2020

Abstract
Due to their high energy, hot electrons in quantum Hall edge (QHE) states can be considered as single particles that have the potential to be used for quantum optics-like experiments. Unlike photons, however, electrons typically undergo scattering processes in transport, which results in a loss of coherence and limits their ability to show quantum-coherent behaviour. Here we study theoretically the decoherence mechanisms of hot electrons in a Mach–Zehnder interferometer (MZI), and highlight the role played by both acoustic and optical phonon emission. We discuss optimal choices of experimental parameters and show that high visibilities of ≳ 85% are achievable in hot-electron devices over relatively long distances of 10 μm. We also discuss energy filtration techniques to remove decoherent electrons and show that this can increase visibilities to over 95%. This represents an improvement over Fermi-level electron quantum optics, and suggests hot-electron charge pumps as a platform for realising quantum-coherent nanoelectronic devices.
Influence of field of view in visual prostheses design: Analysis with a VR system
Authors: Sanchez-Garcia Melani , Martinez-Cantin Ruben , Bermudez-Cameo Jesus , Guerrero Jose J 
Published: September 2020

Abstract

Objective. Visual prostheses are designed to restore partial functional vision in patients with total vision loss. Retinal visual prostheses provide limited capabilities as a result of low resolution, limited field of view and poor dynamic range. Understanding the influence of these parameters in the perception results can guide prostheses research and design. Approach. In this work, we evaluate the influence of field of view with respect to spatial resolution in visual prostheses, measuring the accuracy and response time in a search and recognition task. Twenty-four normally sighted participants were asked to find and recognize usual objects, such as furniture and home appliance in indoor room scenes. For the experiment, we use a new simulated prosthetic vision system that allows simple and effective experimentation. Our system uses a virtual-reality environment based on panoramic scenes. The simulator employs a head-mounted display which allows users to feel immersed in the scene by perceiving the entire scene all around. Our experiments use public image datasets and a commercial head-mounted display. We have also released the virtual-reality software for replicating and extending the experimentation. Main results. Results show that the accuracy and response time decrease when the field of view is increased. Furthermore, performance appears to be correlated with the angular resolution, but showing a diminishing return even with a resolution of less than 2.3 phosphenes per degree. Significance. Our results seem to indicate that, for the design of retinal prostheses, it is better to concentrate the phosphenes in a small area, to maximize the angular resolution, even if that implies sacrificing field of view.
Assessing energy dependence of the transport of relativistic electrons in perturbed magnetic fields with orbit-following simulations
Authors: Särkimäki Konsta , Embreus Ola , Nardon Eric , Fülöp Tünde , contributors JET 
Published: September 2020

Abstract
Experimental observations, as well as theoretical predictions, indicate that the transport of energetic electrons decreases with energy. This reduction in transport is attributed to finite orbit width (FOW) effects. Using orbit-following simulations in perturbed tokamak magnetic fields that have an ideal homogeneous stochastic layer at the edge, we quantify the energy dependence of energetic electrons transport and confirm previous theoretical estimates. However, using magnetic configurations characteristic of JET disruptions, we find no reduction in runaway electron transport at higher energies, which we attribute to the mode widths being comparable to the minor radius, making the FOW effects negligible. Instead, the presence of islands and non-uniform magnetic perturbations are found to be more important. The diffusive-advective transport coefficients calculated in this work, based on simulations for electron energies 10 keV–100 MeV, can be used in integrated disruption modelling to account for the transport due to the magnetic field perturbations.
The cost-effectiveness of energy savings through water conservation: a utility-scale assessment
Authors: Spang Edward S , Manzor Soraya , Loge Frank J 
Published: September 2020

Abstract
It is well-established that water infrastructure systems require energy to treat and deliver water to end-users. This fundamental relationship presents an opportunity to secure energy savings through water conservation. In a previous study, the energy savings linked to a statewide water conservation mandate in California were found comparable in both resource savings as well as cost-effectiveness to the energy savings achieved directly through energy efficiency programs. This study pursues a similar line of inquiry, but at the scale of an individual city as opposed to a statewide assessment. Los Angeles, California, serves as the case study for estimating the energy savings secured through water conservation programs relative to energy efficiency (EE) programs enacted in the study region. We apply three different estimates of energy intensity (EI) for the conversion of water savings to energy savings. These applied EI scenarios are differentiated by scale and system boundary, including: a direct assessment of EI within the water utility service territory, an expanded boundary that includes imported water infrastructure systems, and a broader, top-down estimate for the regional hydrologic zone. Across all scenarios, the estimated energy savings secured through water conservation programs prove to be cost-competitive with the energy efficiency programs enacted by the utility. When using estimates of EI with expanded system boundaries that include the upstream energy embedded in imported water supplies, water conservation becomes a significantly more attractive pathway for saving energy. This outcome underlines the importance of clearly defining the water-energy system boundary of interest, both to determine an accurate EI value, and subsequently, to design and implement cost-effective programs that jointly conserve both water and energy resources.
Boundedness of meta-conformal two-point functions in one and two spatial dimensions
Authors: Henkel Malte , Kuczynski Michal Dariusz , Stoimenov Stoimen 
Published: September 2020

Abstract
Meta-conformal invariance is a novel class of dynamical symmetries, with dynamical exponent z = 1, and distinct from the standard ortho-conformal invariance. The meta-conformal Ward identities can be directly read off from the Lie algebra generators, but this procedure implicitly assumes that the co-variant correlators should depend holomorphically on time- and space coordinates. Furthermore, this assumption implies un-physical singularities in the co-variant correlators. A careful reformulation of the global meta-conformal Ward identities in a dualised space, combined with a regularity postulate, leads to bounded and regular expressions for the co-variant two-point functions, both in d = 1 and d = 2 spatial dimensions.
Pore colmatation in case of liquid corrosion of concrete
Authors: Fedosov S V , Rumyantseva V Eu , Konovalova V S , Evsyakov A S 
Published: September 2020

Abstract
Pore colmatation plays a positive role, since a decrease in the permeability of cement concrete due to the deposition of insoluble corrosion products in the pores leads to a slowdown in corrosion processes. To test a mathematical model of pore colmatation of cement concretes under liquid corrosion, a study of mass transfer processes occurring when samples from Portland cement are exposed to a liquid aggressive medium was conducted. The article presents equations that allow us to determine the rate of pore colmatation and the thickness of the layer of colmatant formed in the pores during liquid corrosion of cement concretes. Based on the results of experimental studies of liquid corrosion of cement stone, the mass transfer parameters were determined in the investigated system «cement concrete – 2 % MgCl2 solution». Based on the obtained data, the values of the colmatation rate and the thickness of the layer of colmatant of cement concrete were calculated during liquid corrosion in a 2 % MgCl2 solution. It has been established that over time, the rate of mass transfer processes occurring in concrete decreases due to the difficulty of penetration of aggressive medium deep into concrete due to the deposition of corrosion products in the pores.
Cement based foam concrete with hardening accelerators
Authors: Steshenko A B , Kudyakov A I , Ryabtseva N E 
Published: September 2020

Abstract
The results of studies of the effect of hardening accelerators on the properties of cement based foam concrete mix and foam concrete of natural hardening are given in this article. The study was conducted in the Laboratory of Tomsk State University of Architecture and Building which is accredited in accordance with the national standards requirements. It has been proposed to decrease the shrinkage deformations of the concrete mix and increase compressive strength of hardened foam concrete by affecting the cement matrix with the calcium chloride and calcium oxalate in the amount of 2 and 0.5% of the cement mass, respectively. This increases the aggregative stability and reduces the plastic shrinkage of the foam concrete mix by 47-65%. In foam concrete with the hardening accelerators the compressive strength rises from 0.31 to 0.47 MPa and from 0.96 to 1.44 MPa at the age of 28 days while maintaining the average density of D400 and D600 respectively. The developed composition of cement based foam concrete is recommended for constructing monolithic walls at a construction site or wall blocks in factory conditions for individual housing construction.
Optical properties of sol-gel coatings containing silver nanoparticles
Authors: Stepin S N , Xolmurodov T A , Mirzaev O O , Katnov V E 
Published: September 2020

Abstract
The technology of receiving the antireflective coating increasing efficiency of use of sunlight in various service conditions is described. Suspensions of nanodimensional silicon dioxide with tetraethoxysilane as a precursor were synthesized to solve the assigned task. The received suspensions were applied by a dipping method on glass samples followed by the coating formation on a surface of the substrates at various temperatures. As a result of a cure of the received samples under natural conditions transparent film of about 500 nanometers thick having very low strength properties on the surface of glass were formed. Heat treatment led to the improvement of strength of coatings in process with increase of temperature up to 600 °C. Exceeding of this temperature resulted in cracking of coatings. In the course of heat treatment higher than 300 °C formation of a coating was accompanied by the thermolysis of silver nitrate that was introduced into silicon dioxide suspension with a formation of silver particles which size was in the nanoscale distance limits according to the results of Auger electron spectroscopy. Presence of evenly distributed silver nanoparticles provided an antireflective effect to coatings which at visual observation found expression in the form of the interference phenomenon. The obtained data confirmed prospects of use of nanosilver as a component of coatings on the basis of silicon dioxide in order to confer the antireflective properties.
Insitu determination of continuous evolution in space and during the strain fields on steel plate with the stress concentrator
Authors: Vlasov V A , Plyaskin A S , Klopotov A A , Potekayev A I , Ustinov A M , Abzayev Yu A , Kurgan A , Bunkov V E , Matskevich N A 
Published: September 2020

Abstract
The article represents the results of the experimental research of the evolution of strain fields of a steel plate with a stress concentrator by the correlation method of digital images. The obtained results reflect elaborately the evolution of the distribution of isofields towards the strains on the surface of the steel plate and the behavior of their distributions, which corresponds to each stage of the stress-strain curve under uniaxial tension.
Role of temperature factor in the work of a cellular reinforced concrete ice-resistant platform
Authors: Zimnyukov V A , Zborovskaya M I 
Published: September 2020

Abstract
The article presents materials reflecting the results of calculations by the finite element method on a computer (according to a special program) of the thermal state of the cellular fragment of the reinforced concrete support block LSP taking into account the influence of seasonal and decadal outdoor temperatures, as well as the effect of changes in the thermal characteristics of the backfill soil on the thermal state of the ice-resistant stationary platform. This made it possible for the first time to evaluate the joint work of a thin reinforced concrete frame and a massive body of backfill soil under temperature effects. In the case of the operation of the cellular structure without the backfill soil, seasonal and ten-day temperature fluctuations create a more unfavourable temperature regime in comparison with the cellular structure with the backfill soil. In the absence of backfill soil, negative temperatures penetrate most deeply into the thickness of the structure. The presented data can also serve as the basis for a preliminary assessment of the thermal state of LSP in the form of a fully cellular reinforced concrete structure and in the future to determine its thermally stressed state. Only considering the combined effect of ice, wave and temperature loads can we really evaluate the operation of such a complex structure in terms of its reliability and safety.
Formation of a comfortable urban environment, taking into account the reconstruction, restoration of buildings and structures (on the example of the Kaliningrad region)
Authors: Pustovgarov V I 
Published: September 2020

Abstract
The issues of reconstruction of the historical environment of cities are one of the most acute when considering the problems of development of urbanized territories. A significant number of examples of the loss of historical monuments make it especially careful to the preserved architectural heritage. The process of revitalizing the planning of the territory in the area of the South (Yuzhniy) Station in the city of Kaliningrad is due to the incompleteness of the town-planning ensemble, which began to form at the end of the 19th century. Urban planning reconstruction of the territory is a complex of necessary scientific research and the preparation of a historical and cultural reference plan, which is defined by the Federal Law “On cultural heritage sites (historical and cultural monuments) of the peoples of the Russian Federation” [1]. As a result of studying the stages of urban development of the historical territory of the city and analyzing its architectural and spatial organization, conceptual proposals for its development were developed.