bluuebunny/crossref_metadata_2025 huggingface dataset:
MFF: An effective method of solving the ill regions in stereo matching
Authors: Qian Ren , Feng Renyan , Xie Wangduo , Yang Wenbang , Zhao Yong
Published: April 2023

In the current stereo matching field, the accuracy of the derived disparity map is highly dependent on the processing capability of ill regions. Fortunately, we find that the use of local information will eliminate the negative effects associated with ill regions. As a result of the above discovery, we propose the Concatenated Dilated Convolution (CDC) block and the Multi‐scale Feature Fusion module (MFF), which are capable of effectively extracting regional context by increasing the receptive field in parallel and channel‐wise ways. The CDC block can expand the receptive field by applying multiple dilated convolutions at different dilation rates in parallel to enhance the smoothness of the feature map. By constructing parallel CDC blocks in a multiple dilated manner, the MFF module can improve the smoothness of the feature map. In addition, to control the number of parameters in the MFF network, a high‐performance channel‐distribution algorithm is proposed, capable of adjusting the weights of each module and convolution in an adaptive manner while reducing the number of parameters. Extensive experiments have demonstrated that MFF and CDC can effectively improve the performance of ill areas and networks with a minimal number of parameters.
A novel approach to compensate delay in communication by predicting teleoperator behaviour using deep learning and reinforcement learning to control telepresence robot
Authors: Naseer Fawad , Khan Muhammad Nasir , Rasool Akhtar , Ayub Nafees
Published: April 2023

Robots with telepresence capabilities are typically employed for tasks where human presence is not feasible due to geography, safety risks like fire or radiation exposure, or other factors like any epidemic disease. Time delay is a significant consideration in controlling a telepresence robot. This study proposes a deep learning‐based approach to compensate for the delay by predicting the behaviour of the teleoperator. The authors integrate a recurrent neural network (RNN) based on the Long Short‐Term Memory (LSTM) architecture with the reinforcement learning‐based Deep Deterministic Policy Gradient (DDPG) algorithm. The proposed method predicts the teleoperator's angular and linear controlling commands by using data gathered by embedded sensors on the specially designed and built telepresence robot. Simulations and experiments assess the operation of the proposed technique in Gazebo simulation and MATLAB with robot operating system (ROS) integration, which shows 2.3% better response in the presence of static.
An interleaved high step‐down coupled inductor based quadratic DC‐DC converter
Authors: Pashaie Reza , Sabahi Mehran , Babaei Ebrahim
Published: April 2023

A high step‐down direct current‐direct current (DC‐DC) buck converter with a coupled‐inductor in its topology is presented in this study. The switching pattern of the proposed converter is interleaved; therefore, the voltage stress on the semiconductors and the components is low since the primary high voltage will be divided between the blocking capacitors on the primary side. Thus, the voltage stress on semiconductor elements will be low. As a result, the preselected elements can be chosen with low voltage ratings. In addition, there are cells with coupled inductors utilized in the structure that helps the converter to provide improved voltage gain in its output terminal. Typically, narrow duty cycles are needed to achieve high gain in conventional buck converters, but the proposed converter has obtained a high conversion ratio even with wider duty ratios. Besides, the proposed converter has a constant equation for the voltage gain for the whole range of duty cycles. Theoretical analysis and comparison with other recent converters of similar types have been conducted to demonstrate the proposed converter performance. Furthermore, to verify the theoretical analysis, a 600 W prototype of the proposed converter with 820 V/30 V is implemented, and experimental results are presented.
Gaussian processes for radial velocity modeling
Authors: Stock Stephan , Kemmer Jonas , Kossakowski Diana , Sabotta Silvia , Reffert Sabine , Quirrenbach Andreas
Published: April 2023

Context. Instrumental radial velocity (RV) precision has reached a level where the detection of planetary signals is limited by the ability to understand and simultaneously model stellar astrophysical “noise.” A common method for mitigating the effects of stellar activity is Gaussian process (GP) regression.

Aims. In this study we present an analysis of the performance and properties of the quasi-periodic (QP) GP kernel, which is the multiplication of the squared-exponential kernel by the exponential-sine-squared kernel, based on an extensive set of synthetic RVs, into which the signature of activity was injected.

Methods. The stellar activity within our synthetic data sets was simulated using astrophysically motivated models with different spot distributions and spot lifetimes rotating on the surface of a modeled late-type star. We used dynamic nested sampling to fit different model sets, including QP–GPs, Keplerian models, white noise models, and combinations of these, to synthetic RV time series data that in some cases included additional injected planetary signals.

Results. We find that while the QP–GP rotation parameter matches the simulated rotation period of the star, the length scale cannot be directly connected to the spot lifetimes on the stellar surface. Regarding the setup of the priors for the QP–GP, we find that it can be advantageous to constrain the QP–GP hyperparameters in different ways depending on the application and the goal of the analysis. We find that a constraint on the length scale of the QP–GP can lead to a significant improvement in identifying the correct rotation period of the star, while a constraint on the rotation hyperparameter tends to lead to improved planet detection efficiency and more accurately derived planet parameters. Even though for most of the simulations the Bayesian evidence performed as expected, we identified not far-fetched cases where a blind adoption of this metric would lead to wrong conclusions.

Conclusions. We conclude that modeling stellar astrophysical noise by using a QP–GP considerably improves detection efficiencies and leads to precise planet parameters. Nevertheless, there are also cases in which the QP–GP does not perform optimally, for example RV variations dynamically evolving on short timescales or a mixture of a very stable activity component and random variations. Knowledge of these limitations is essential for drawing correct conclusions from observational data.
Real-time Power System Topology Recognition through Convolutional Neural Networks
Authors: Gotman Natalja , Shumilova Galina
Published: April 2023

This paper investigates the status of a transmission line (on/off) using a 140-bus Northeast Power Coordinating Council (NPCC) test system model [1]. The application of the software package ANDES [2] to obtain a database when solving this problem in the transient process of the power system is considered. The Deep Learning Neural Networks (DLNN) [3] were proposed to solve the problem, in particular, a convolutional neural network (CNN), the input variables of which are voltage and current phasors obtained from phasor measurement units (PMU). Calculations to determine the state of lines were performed using a program developed in the Julia language using the Flux package (a machine learning library that includes functions for creating CNN models). The results of the studies are presented.
On the functioning of capacitor banks in smart grids
Authors: Kovernikova Lidiia
Published: April 2023

The amount of electronic equipment is increasing in created smart grids. This equipment introduces distortions into the electrical network, due to which the voltages at the network nodes, and hence the currents, become nonsinusoidal. The paper is devoted to the analysis of the effect of capacitor banks on the electrical network with nonsinusoidal mode parameters due to the resonant circuits they create with the electrical network at harmonic frequencies, as well as the influence of nonsinusoidal network modes on capacitor banks. The paper presents an overview of scientific publications on the problem of harmonic resonances in nonsinusoidal network modes, as well as the values of power quality indices that were measured in the study of the effect of the capacitor bank on the network mode. With the help of the “Harmonics” software package, the reduction in the service life of the capacitor bank in the nonsinusoidal mode, the frequency characteristics of admittance, conductance, susceptance of the network node with the capacitor bank, and the resonant powers of the capacitor bank at harmonic frequencies were calculated.
Ensuring the reliability of energy systems with the application of a new method of decreasing seasonal variations of ground resistance
Authors: Pavlovich Ivan , Baraishuk Siarhei , Skripko Alexey
Published: April 2023

The possibility of improving the reliability of the grounding system is shown. The analysis of dependence of soil resistivity on humidity was carried out, on the basis of which a composition for normalization (reduction of seasonality) of soil electrical resistivity was proposed. A number of full-scale experiments were carried out to measure the resistance values of the grounding devices of experimental circuits, after backfilling the places of laying the contour elements with various compositions and introducing other types of soils and minerals.
Power consumption management and equalization of the load schedules of Azerbaijan power system
Authors: Yusifbayli Nurali , Nasibov Valeh , Alizade Rana
Published: April 2023

Foreign experience in applying the principles of power consumption management is analyzed in the paper. A comparative analysis of the main indicators of the load schedules of the power systems of Azerbaijan, Turkey, Ukraine, Russia and Jordan was carried out and it was found out that there is significant potential for improving such indicators of the load schedules as variation factor and the fill factor for the Azerbaijan power system. The positive effects of equalization of the load schedules of the power system of Azerbaijan are studied, based on the technical and economic indicators of the main generating capacities.
Hidden Markov Model and States Prediction of an Autonomous Wind-Diesel Complex
Authors: Obzherin Yuriy E. , Sidorov Stanislav M. , Fedorenko Sergey N.
Published: April 2023

The problem of assessing the reliability and analyzing the functioning of an autonomous winddiesel complex, consisting of a wind power plant, working and standby diesel generators, an inverter and a storage battery, is considered. First, a semi-Markov model of an autonomous wind-diesel complex is built, which makes it possible to calculate the stationary and temporal reliability characteristics. Then, on its basis, a hidden Markov model is developed, which is used to solve the problems of predicting and evaluating its characteristics, taking into account the given parameters and the signal vector. The results of the study are obtained in a general form and are invariant with respect to the laws of distribution of random variables describing the elements of an autonomous wind-diesel complex. They allow you to simulate the functioning of the system under various distribution laws, based on statistical data, without modifying the model itself.
Comparative efficiency of application of the maximum clique method in searching for critically important objects of the gas industry
Authors: Vorobev Sergey , Kolosnitsyn Anton , Minarchenko Ilya
Published: April 2023

The article proposes the use of a model of the "defender - attacker - defender" type to determine the possibilities of the gas industry to reduce gas shortages for consumers in the event of failure of its critical facilities. The calculation scheme of the gas transmission network in this study is presented in the form of a directed graph, in the nodes of which there are objects of production, consumption, storage of gas and nodal compressor stations. All found cliques are analyzed, and a list of measures aimed at reducing possible gas shortages among consumers is compiled. The article presents the results of the analysis. The results of applying the method of determining the maximum cliques to search for critical objects of the gas industry were evaluated in comparison with the results obtained earlier on this topic. Conclusions are drawn about the feasibility of using the proposed method to determine the critically important objects of the gas industry.
Impact of climate change on electrical energy losses in electrical networks
Authors: Taslimov A.D.
Published: April 2023

One of the global problems in the world is greenhouse gas emission. There are several reasons for this problem, one of which is electricity. This article provides a brief summary of the current state of electricity waste and analyzes the impact of electricity waste on greenhouse gas emissions, as well as ways to reduce greenhouse gas emissions from the point of view of electricity generation. The situation of greenhouse gas emission in the territory of Uzbekistan and how much of it corresponds to the share of electricity losses is shown.
Development and research of non-contact starting devices for electric consumers and motors
Authors: Fayziyev Makhmanazar , Tuychiev Furkat , Mustayev Ruslan , Ochilov Yunus
Published: April 2023

This article presents the analysed information about power consumers and electric motor starters in order to ensure the reliable operation of the power supply system, which is relevant today. Disadvantages of contact starters used for small power electric motors in the power supply system and advantages of non-contact starters are given. In addition, it is based on the creation of additional opportunities when using this device, that is, it creates opportunities for protection and automatic control. Contactless starters are recommended for some heavy-duty electric motors. The article describes these cases in details.
Optimization of electricity generation mode, energy-intensive units, operating and various regimes production
Authors: Hoshimov F.A. , Najimova A.M. , Rafikova G.R. , Bakhadirov I.I.
Published: April 2023

The article provides an analysis of the optimization of the modes of electrical loads of energy-intensive units operating in various production modes, in particular, the mode of continuous operation of the unit, the mode of continuous operation, the mode of continuous operation of the unit with a constant hourly output, the mode of continuous operation of the unit with varying productivity, the operation of the unit in variable mode. And also measures are proposed to reduce power consumption, taking into account the technological process.
Application of numerical and graphical methods of analysis in nonlinear resistive circuits of electronic devices
Authors: Abduraimov Erkin , Nurmatov Baxtiyor
Published: April 2023

The article discusses the research issues and methods of analysis of semiconductor circuits used in electronic circuits of contactless switching devices, provides analytical, graphic and numerical methods for the analysis of nonlinear semiconductor resistive circuits. The approximations of the Volt-Ampere characteristics (VACh) of semiconductor elements and the solution of the differential equations of state of electrical circuits by a numerical method using a computer are given. Diode, thyristor semiconductor nonlinear resistive circuits with active and inductive loads are considered. In the analysis of steady-state modes and transient processes, numerical methods for solving differential equations of states by the Euler method were used.
New pole-changing winding for electric drive of ball mills
Authors: Rismukhamedov Dauletbek , Shamsutdinov Khusniddin , Ganiev Sarvar , Magdiev Khayotullo , Khusanov Shakhobiddin
Published: April 2023

The article substantiates the expediency of using a controlled electric motor in grinding mechanisms in electric drives instead of an unregulated asynchronous motor. The problem of facilitating the start-up of ball mills and ensuring accurate stop of the neck of ball mills using the lowest speed is considered. As the review of the literature showed, speed control in electric drives using two-speed motors is a simple, cheap and reliable option. In many existing two-speed motors, two independent windings are placed in the stator slots; for this reason, the motor magnetic circuit is not effectively used, in turn, the use of one pole-changing winding improves the energy performance of the motor and saves winding copper and insulating materials. Based on the analysis of the operating modes of grinding mechanisms, in terms of facilitating start-up and resource saving (increase the operating time of the engine itself), the expediency of creating a two-speed motor with a pole-changing winding with a pole ratio of 2:5 and improving existing electric drive systems with its use is substantiated.
A comparative study on a firm’s optimal production decision considering risk aversion and carbon policies
Authors: Qi Qi , Bai Qingguo , Xu Jianteng , Feng Qian
Published: April 2023

To cope with global warming and achieve the goal of carbon emission reduction, various carbon policies have been implemented in many countries and regions. Some studies have indicated that with the popularity of low carbon, a small proportion of consumers show a green purchasing tendency. However, for firms, it is still difficult to predict the green purchase preferences of most consumers, and firms may face greater market demand uncertainty, which will bring profit risks. We assume that a firm’s decision is subject to its behavioral considerations, that is, its risk attitude. Considering the risk preferences of decision-makers and carbon emission policies, this paper addresses decision optimization in operations management. Our purpose is to analyze the optimal production decisions of risk-averse firms under carbon cap and carbon tax policies. Adopting the CVaR (conditional value-at-risk) criterion, we construct an optimization model with the constraints of carbon policies and obtain the analytic formula of optimal solutions. Then, we compare the optimal operational decisions for risk-averse firms and risk-neutral firms and further explore the impact of risk aversion on production and the parameters of carbon policy. Finally, some numerical studies are presented to analyze the carbon policies and risk aversion on firms’ operational decisions and give some managerial insights based on the analysis results.
Präoperatives Ernährungsmanagement in der großen Tumorchirurgie des Bauchraumes an deutschen Kliniken. Eine explorative Strukturanalyse
Authors: Wendt Saskia , Meißner Carl
Published: April 2023

Bis zu 80 % der PatientInnen vor Tumorresektionen des oberen Gastrointestinaltrakts sind mangelernährt. Dabei hat schon der präoperative Ernährungszustand einen signifikanten Einfluss auf den perioperativen Verlauf. Ein adäquater präoperativer Ernährungszustand, der unter anderem die Komplikationsrate und die Krankenhausliegedauer reduzieren kann, ist daher erstrebenswert. Zwar empfehlen einschlägige Leitlinien Maßnahmen zur Erkennung und Behandlung einer Mangelernährung, jedoch fehlt es bislang an Vorschlägen zur Planung eines strukturieren präoperativen Ernährungsmanagements auf die BehandlerInnen zurückgreifen können. Innerhalb dieser Arbeit wurden 40 Krankenhäuser in Deutschland deshalb zu individuell vorhandenen Strukturen und Maßnahmen zum präoperativen Ernährungsmanagement von PatientInnen vor Tumorresektionen des oberen Gastrointestinaltrakts befragt. Die Befragungen zeigen, dass Maßnahmen zur Erkennung und Therapie einer präoperativen Mangelernährung mehrheitlich bekannt und akzeptiert sind. So befürworten 35 der 40 TeilnehmerInnen eine präoperative Ernährungstherapie bei mangelernährten PatientInnen, 26 TeilnehmerInnen erwägen hierfür sogar einen Aufschub der Operation. Eine flächendeckende Umsetzung an den Kliniken scheitere jedoch häufig an Hinderungsgründen, wie fehlender Sichtbarkeit der Ernährung als Therapiebaustein unter BehandlerInnen, labilen Verantwortlichkeiten sowie unzureichenden finanziellen und personellen Ressourcen. Mögliche Lösungsvorschläge zum Abbau der Hindernisse reichen von Refinanzierungsmöglichkeiten der klinischen Ernährungstherapie bis hin zu Forderungen auf gesundheitspolitischer Ebene. Aus den Erkenntnissen aktueller Studien und Leitlinien, sowie den Ergebnissen der Befragung, unterbreitet diese Arbeit einen Vorschlag zur Implementierung eines präoperativen Ernährungsmanagements. Dessen Umsetzbarkeit im klinischen Alltag sollte dabei durch wissenschaftliche Verfahren begleitet werden.
A Comparison of Changes in the Mean Arterial Blood Pressure and Mean Uterine Artery Pulsatility Index from 11–14 to 19–24 + 6 Gestation Weeks in Low-Risk and High-Risk Asian Indian Pregnant Women
Authors: Baghel Akanksha , Patekar Tejashree Y. , Choorakuttil Rijo M. , Sharma Lalit K. , Satarkar Shilpa R. , Gupta Anjali , Aneja Kavita , Dhankhar Sandhya , Chhajer Gulab , Dwivedi Somya , Jain Mansi , Shentar Srinivas , Nirmalan Praveen K.
Published: April 2023

Aim The aim of this study was to determine the changes in the mean arterial blood pressure (MAP) and mean uterine artery (UtA) pulsatility index (PI) from 11-14 to 19-24 + 6 gestation weeks in Asian Indian pregnant women.

Methods Clinical and demographic details, MAP, and mean UtA PI measures were ascertained for pregnant women at 11 to 14 gestation weeks and 19–24 + 6 gestation weeks. Women were categorized as a high-or-low risk for preterm preeclampsia using the Fetal Medicine Foundation algorithm and 1 in 150 cutoff. High-risk pregnant women were recommended low-dose aspirin 150 mg daily at bedtime. Changes in MAP and mean UtA PI were compared for gestational age intervals and high-and-low risk women using nonparametric tests.

Results The study analyzed the results of 1,163 pregnant women. Both MAP (mean difference: 5.14, p < 0.001) and mean UtA PI (mean difference: 0.14, p < 0.001) remained significantly higher at the second-trimester assessment in high-risk pregnant women compared to low-risk pregnant women. Seventy-seven (35.16%) of the 219 pregnant women with abnormal mean UtA PI in the first trimester had an abnormal mean UtA PI in the second-trimester assessment. One hundred (10.59%) of the 944 pregnant women with normal mean UtA PI in the first trimester had an abnormal mean UtA PI in the 19-24 + 6 weeks assessment. Seventy-seven pregnant women (6.62% of 1,163 women, 95% confidence interval: 5.33, 8.20) had an abnormal mean UtA PI at both gestation age intervals. High-risk pregnant women taking low-dose aspirin daily showed a larger reduction in mean UtA PI compared to high-risk pregnant women that did not report the use of low-dose aspirin (0.89 vs. 0.62, p <0.001)

Conclusion MAP and mean UtA PI decreased significantly from the first to the second trimester of pregnancy. Sequential assessment of the MAP and mean UtA PI in the first and second trimesters of pregnancy will be useful for fetal radiologists in India to identify a subgroup of women with abnormal mean UtA PI at both trimesters that may need more intense surveillance and follow-up till childbirth.
Making choices: prioritising the protection of biodiversity in wildfires
Authors: Woinarski John C. Z. , McCormack Phillipa C. , McDonald Jan , Legge Sarah , Garnett Stephen T. , Wintle Brendan , Rumpff Libby
Published: April 2023

Biodiversity is in chronic decline, and extreme events – such as wildfires – can add further episodes of acute losses. Fires of increasing magnitude will often overwhelm response capacity, and decision-makers need to make choices about what to protect. Conventionally, such choices prioritise human life then infrastructure then biodiversity. Based on shortcomings revealed in the 2019–20 Australian wildfires, we propose a series of linked steps that can be used to identify and prioritise biodiversity assets (including their priority relative to other types of assets), enhance and implement their protection through planning and practice, and strengthen legislation to safeguard them.
Human atlastin-3 is a constitutive ER membrane fusion catalyst
Authors: Bryce Samantha , Stolzer Maureen , Crosby Daniel , Yang Ruijin , Durand Dannie , Lee Tina H.
Published: April 2023

Homotypic membrane fusion catalyzed by the atlastin (ATL) GTPase sustains the branched endoplasmic reticulum (ER) network in metazoans. Our recent discovery that two of the three human ATL paralogs (ATL1/2) are C-terminally autoinhibited implied that relief of autoinhibition would be integral to the ATL fusion mechanism. An alternative hypothesis is that the third paralog ATL3 promotes constitutive ER fusion with relief of ATL1/2 autoinhibition used conditionally. However, published studies suggest ATL3 is a weak fusogen at best. Contrary to expectations, we demonstrate here that purified human ATL3 catalyzes efficient membrane fusion in vitro and is sufficient to sustain the ER network in triple knockout cells. Strikingly, ATL3 lacks any detectable C-terminal autoinhibition, like the invertebrate Drosophila ATL ortholog. Phylogenetic analysis of ATL C-termini indicates that C-terminal autoinhibition is a recent evolutionary innovation. We suggest that ATL3 is a constitutive ER fusion catalyst and that ATL1/2 autoinhibition likely evolved in vertebrates as a means of upregulating ER fusion activity on demand.
Estimation of tropospheric parameters with GNSS smartphones in a differential approach
Authors: Stauffer R , Hohensinn R , Herrera Pinzón I D , Moeller G , Pan Y , Kłopotek G , Soja B , Brockmann E , Rothacher M
Published: April 2023

With the introduction of the operating system Android 7 Nougat in the year 2016, it became possible to access Global Navigation Satellite System (GNSS) code and carrier phase observations. These observations can be processed with the state-of-the-art GNSS processing software packages, which allows an in-depth evaluation of the smartphone’s GNSS performance. The availability of carrier phase observations enables sub-decimeter-level positioning. A few years ago, smartphones wearing dual-frequency GNSS chipsets hit the mass market. In this study, we investigate the capability of such a device for the estimation of tropospheric delays. Static measurements carried out over the period of two weeks are performed using a Google Pixel 4 XL smartphone. The measurements are processed using relative positioning methods with a baseline length of about 33 kilometers, where a continuously operating reference station (CORS) acts as a base. The estimated differential zenith tropospheric wet delay (dZWD), obtained for the smartphone are then combined with absolute values computed at the reference station, in order to obtain time series of Zenith Total Delay (ZTD). Using this method, we demonstrate that high-precision ZTDs can be successfully determined from smartphone GNSS observations. When comparing the estimated tropospheric delays with those determined at a nearby geodetic receiver to assess the accuracy of the acquired time series of ZTD, differences in the range of few millimeters to a centimeter are visible. We examine the impact of various error sources, such as antenna phase center variations and residual effects of the ionosphere. Given that the obtained accuracies are at the level of a centimeter and below, the suggested method shows the potential to resolve small-scale tropospheric structures in near real-time, and thus, could be an interesting data source for numerical weather prediction models or related GNSS crowdsourcing projects.
Electron-beam synthesis of ceramic- and boron-based coatings
Authors: Tyunkov A V , Andronov A A , Zolotukhin D B , Yushkov Yu G
Published: April 2023

We report the results of our experimental investigations on the synthesis of coatings based on various ceramics and boron. The coatings were synthesized by electron-beam evaporation of solid dielectric targets of Al2O3, YSZ, Al2O3Cr, and B. The deposition rates for coatings based on these materials were measured. The deposition rate of defect-free coatings was 1200–1600 nm min−1. The obtained coatings, up to 5 μm thick, were studied in terms of their morphology, structure, and tribological properties. The coatings are uniform in thickness, composition and free of impurities. The coatings, with the exception of the zirconium oxide film, have a predominantly amorphous structure. Comparisons of their mechanical and tribological characteristics are presented. The hardness of the coatings formed from YSZ was 0.4 GPa, from aluminum oxide ceramics 4–6 GPa, and from boron 11 GPa. Boron-based coatings were found to be the most wear-resistant (with wear coefficient about 8.9·10−6 mm3 N−1·m−1).
Forecasts of CMB lensing reconstruction of AliCPT-1 from the foreground cleaned polarization data
Authors: Han Jiakang , Hu Bin , Ghosh Shamik , Li Siyu , Dou Jiazheng , Delabrouille Jacques , Jin Jing , Li Hong , Liu Yang , Remazeilles Mathieu , Zhao Wen , Zhang Pengjie , Li Zheng-Wei , Liu Cong-Zhan , Zhang Yong-jie , Kuo Chao-Lin , Zhang Xinmin
Published: April 2023

The gravitational lensing distortion of Cosmic microwave background radiation (CMB)
carries fruitful information of cosmic large-scale structure. However, CMB observations are
unavoidably contaminated by emission from various extra-galactic foregrounds, which must be
removed to obtain reliable measurements of the cosmological signal. In this paper, we demonstrate
CMB lensing reconstruction in AliCPT-1 after foreground removal, combine the two bands of AliCPT-1
(90 and 150 GHz) with Planck HFI bands (100, 143, 217 and 353 GHz) and with the WMAP-K band
(23 GHz). In order to balance contamination by instrumental noise and foreground residual bias,
we adopt the Needlet Internal Linear Combination (NILC) method to clean the E-map and the
constrained Internal Linear Combination (cILC) method to clean the B-map. The latter utilizes
additional constraints on average frequency scaling of the dust and synchrotron to remove
foregrounds at the expense of somewhat noisier maps. Assuming 4 modules observing 1 season from
simulation data, the resulting effective residual noise in E- and B-map are roughly 15 μ
K· arcmin and 25 μ K· arcmin, respectively. As a result, the CMB
lensing reconstruction signal-to-noise ratio (SNR) from polarization data is about
SNR≈4.5. This lensing reconstruction capability is comparable to that of other
stage-III small aperture millimeter CMB telescopes.
Axion haloscope signal power from reciprocity
Authors: Egge Jacob
Published: April 2023

Axion haloscopes search for dark matter axions from the galactic halo, most commonly by measuring a power excess sourced by the axion effective current density. Constraining axion parameters from detection or lack thereof requires estimating the expected signal power. Often, this is done by studying the response of the haloscope to a known, but different, source current density, for example via a reflection measurement. However, only in the special case when both sources induce the same electromagnetic fields, do the quantities derived from a reflection measurement adequately describe the setup during an axion measurement. While this might be valid for the traditional resonant cavity haloscope, new broadband or open designs like dish antennas or dielectric haloscopes cannot make this assumption. A more general relation between axion- and reflection-induced fields is needed. In this article, we use the Lorentz reciprocity theorem to derive an expression for the axion signal power which instead of the unmeasurable axion-induced fields depends on the measurable reflection-induced fields. This entirely circumvents the need to know the response of the haloscope to the unknown axion source. It applies to a wide variety of haloscopes including resonant cavities, dielectric haloscopes, and broadband dish antennas.
Uncovering gravitational-wave backgrounds from noises of unknown shape with LISA
Authors: Baghi Quentin , Karnesis Nikolaos , Bayle Jean-Baptiste , Besançon Marc , Inchauspé Henri
Published: April 2023

Detecting stochastic background radiation of cosmological origin is an exciting possibility for current and future gravitational-wave (GW) detectors. However, distinguishing it from other stochastic processes, such as instrumental noise and astrophysical backgrounds, is challenging. It is even more delicate for the space-based GW observatory LISA since it cannot correlate its observations with other detectors, unlike today's terrestrial network. Nonetheless, with multiple measurements across the constellation and high accuracy in the noise level, detection is still possible. In the context of GW background detection, previous studies have assumed that instrumental noise has a known, possibly parameterized, spectral shape. To make our analysis robust against imperfect knowledge of the instrumental noise, we challenge this crucial assumption and assume that the single-link interferometric noises have an arbitrary and unknown spectrum. We investigate possible ways of separating instrumental and GW contributions by using realistic LISA data simulations with time-varying arms and second-generation time-delay interferometry. By fitting a generic spline model to the interferometer noise and a power-law template to the signal, we can detect GW stochastic backgrounds up to energy density levels comparable with fixed-shape models. We also demonstrate that we can probe a region of the GW background parameter space that today's detectors cannot access.
Plasma local diagnostics by polarimetric method
Authors: Oganesyan Koryun B , Dzierżęga Krzysztof , Gevorgyan Ashot H , Hnatic Michal , Kopcansky Peter
Published: April 2023

We study the polarization plane rotation of weak probe signal in the field of strong electromagnetic waves in the presence of an external magnetic field of plasma, the polarization plane stimulated rotation angle of the probe signal in the intense laser field and in plasma is calculated. The estimates of the residual gas local density in a cesium plasma based on the effects of Faraday, Cotton–Mouton and stimulated rotation of the probe signal in the intense laser field have been found. It is shown, that the rotation angle in the cesium plasma medium has a complex structure.
Structural diversity and optoelectronic properties of chemical modification pentagonal quantum dots
Authors: Thao Pham Thi Bich , Hang Nguyen Thi My , Dang Nguyen Hai , Nhat Pham Vu , Tien Nguyen Thanh
Published: April 2023

A first-principle study of the structural diversity and optoelectronic properties of the small penta-graphene quantum dots (PGQDs) has been performed. The stability and optoelectronic properties of the PGQDs are investigated under the effect of chemical modifications. PGQDs are edge functionalized by non-metallic atoms (Si, P, O, F) such as identical edge termination (Si-PGQD, P-PGQD, O-PGQD, F-PGQD) and alternate edge termination (Si-O-PGQD, H-P-PGQD). Further, H-PGQDs are also doped and co-doped with B and P atoms. All studied structures are stable with strong electronic quantization and exhibit semiconducting or metallic properties depending on the termination, doping elements and their site. Absorption peaks in the visible region were not observed for hydrogen passivation PGQDs. However, some absorption peaks appear in this region for edge-passivated. In addition, there are dramatic changes in the electronic properties of B, P, BP-doped PGQDs to give peak shifts to the visible region from the ultraviolet region of the pure sample due to hybridization effects. The enhanced reactivity, controllable electronic properties of edge passivation, and doping make PGQDs ideal for new nanodevice applications.
High-efficiency recovery of 82Se from enriched Zn82Se scintillating bolometer crystals
Authors: Balabanov S.S. , Broerman B. , Dafinei I. , Filofeev S.V. , Laubenstein M. , Nagorny S.S. , Nisi S. , Pagnanini L. , Pirro S.
Published: April 2023

As experiments searching for neutrinoless double beta decay push into the inverted hierarchy, enriched isotope target masses of hundreds of kilograms are required. Due to unavoidable losses throughout the entire production chain, the recovery of expensive enriched material used in crystal-based experiments should be given special attention. The CUPID-0 experiment using Zn82Se scintillating bolomoters provides a unique opportunity at the 10-kg-scale to test a recovery process for enriched 82Se. We present a multi-stage, high-yield method consisting of wet chemistry and vacuum distillation. The chemical purity, isotopic abundance, and radiopurity is demonstrated to be preserved after the 82Se extraction with recovery efficiency no less than 86.4% (that potentially can be higher than 94.7%) and chemical purity of 99.999%.
A method to measure the quenching factor for recoil energy of oxygen in bismuth germanium oxide scintillators
Authors: Ommura Yuga , Ito Hiroshi , Yano Takatomi , Minamino Akihiro , Ishitsuka Masaki
Published: April 2023

Bismuth germanium oxide (Bi4Ge3O12, BGO) scintillation crystals are widely
used as detectors in the fields of particle physics and astrophysics due to their high density,
and thus higher efficiency for gamma-ray detection. Owing to their good chemical stability, they
can be used in any environment. For rare-event searches, such as dark matter and coherent elastic
neutrino-nucleus scattering, BGO crystals are essential to comprehend the response of nuclear
recoil. In this study, we have analyzed the events of neutron elastic scattering with oxygen in
BGO crystals. Then, we have measured the quenching factor for oxygen recoil energy in the BGO
crystal as a function of recoil energy by using a monoenergetic neutron source.
Recent advancement in water quality indicators for eutrophication in global freshwater lakes
Authors: Suresh Keerthana , Tang Ting , van Vliet Michelle T H , Bierkens Marc F P , Strokal Maryna , Sorger-Domenigg Florian , Wada Yoshihide
Published: April 2023

Eutrophication is a major global concern in lakes, caused by excessive nutrient loadings (nitrogen and phosphorus) from human activities and likely exacerbated by climate change. Present use of indicators to monitor and assess lake eutrophication is restricted to water quality constituents (e.g. total phosphorus, total nitrogen) and does not necessarily represent global environmental changes and the anthropogenic influences within the lake’s drainage basin. Nutrients interact in multiple ways with climate, basin conditions (e.g. socio-economic development, point-source, diffuse source pollutants), and lake systems. It is therefore essential to account for complex feedback mechanisms and non-linear interactions that exist between nutrients and lake ecosystems in eutrophication assessments. However, the lack of a set of water quality indicators that represent a holistic understanding of lake eutrophication challenges such assessments, in addition to the limited water quality monitoring data available. In this review, we synthesize the main indicators of eutrophication for global freshwater lake basins that not only include the water quality constituents but also the sources, biogeochemical pathways and responses of nutrient emissions. We develop a new causal network (i.e. multiple links of indicators) using the DPSIR (drivers-pressure-state-impact-response) framework that highlights complex interrelationships among the indicators and provides a holistic perspective of eutrophication dynamics in freshwater lake basins. We further review the 30 key indicators of drivers and pressures using seven cross-cutting themes: (i) hydro-climatology, (ii) socio-economy, (iii) land use, (iv) lake characteristics, (v) crop farming and livestock, (vi) hydrology and water management, and (vii) fishing and aquaculture. This study indicates a need for more comprehensive indicators that represent the complex mechanisms of eutrophication in lake systems, to guide the global expansion of water quality monitoring networks, and support integrated assessments to manage eutrophication. Finally, the indicators proposed in this study can be used by managers and decision-makers to monitor water quality and set realistic targets for sustainable water quality management to achieve clean water for all, in line with Sustainable Development Goal 6.
Research on deep utilization technology of flue gas residual heat for large-capacity coal-fired units
Authors: Li Mingcheng , Li Guipeng , Lu Xizhen , Zhang Mingzhao
Published: April 2023

The utilization of flue gas waste heat is an important measure to improve the power efficiency of coal-fired units. Traditional method is to arrange the heating surface after the air preheater, which can just recover the low-grade heat, low efficiency. For the engineering practice of a 1000MW double-reheat unit, three feasible schemes are proposed, namely scheme 1 “two-stage gas cooler plus cold air heater”, scheme 2 “air preheater bypass + two-stage flue gas cooler plus cold air heating” and scheme 3 “air preheater bypass + hot primary air temperature adjustment plus two-stage flue gas cooler plus cold air heater”. For the sake of evaluating the actual effects of different schemes objectively, the thermal characteristic calculation model of the four-part rotary air preheater was established by finite difference method, and then the effect of the inlet air temperature and the share of bypass flue gas on the thermal efficiency of the boiler were studied. The equivalent enthalpy drop method was used to establish the thermal characteristic model of steam turbine, and the influence of different heat distribution modes on the heat consumption rate of steam turbine was studied.. Considering the technical economy, the optimal bypass flue gas share of this scheme is 12%, which corresponds to the reduction of coal consumption for power supply of the unit by about 3.23g/kWh. Taking into account comprehensively, scheme 3 is recommended.
Research on the effect of the flue gas recirculation on the combustion and operating economy of circulating fluidized bed boiler
Authors: Xie Guowei , Gu Congyang , Cao Peiqing , Zhang Peng , Duan Shoubao , She Jiangang , Liu Xiaoping , Xin Shengwei , Guo Rui , Du Jiajun , Wang Hu , Han Xinjian
Published: April 2023

To meet the requirements of the power grid’s deep peak shaving, a 300MW CFB boiler in a power plant transformed the flue gas recirculation. After the transformation, it is found that after putting into the flue gas recirculation, the main parameters of the boiler such as environmental protection emission value, the boiler operating bed temperature, and the inlet temperature of the separator had changed. To analyze the changes, this paper was carried out by related thermal state tests during the start-up or the normal operation of the boiler. The operating data of the boiler was collected before and after putting into the flue gas recirculation, and the influence of the gas recirculation on the main parameters and economic indicators of the boiler is quantitatively analyzed and discussed. The result shows that the technology of the flue gas recirculation can reduce the oxygen content in the dense phase area of the furnace and increases the reducing gas atmosphere to reduce the generation of NOX emission during the start-up or in the normal operation of the boiler. This provides a technical reference that optimizes the operation mode of the flue gas recirculation during the deep peak shaving in the CFB boiler.
Dynamic positioning filter design applied on the small ship
Authors: Wang Feng , Lv Jingze , Yue Rongqin , Lu Jie , Liu Yaqi
Published: April 2023

This paper investigates a filter design method for dynamic positioning control system based on the wave peak frequency tracking algorithm. The wave peak frequency varies randomly with the sea condition, ship speed, wave direction and other factors. The performance of the filter is greatly affected by the real-time recognition of the wave peak frequency. The wave disturbance model is indicated as an autoregressive moving average (ARMA) model and the recursive extended least squares (RELS) algorithm is proposed to identify the wave peak frequency with the auxiliary model idea. A filter with the wave peak frequency tracker is constructed to evaluate the effectiveness of the proposed filter. Ultimately, simulation results show that the proposed filter can effectively track the wave peak frequency and can still effectively reduce the influence of waves on the ship control system when the peak frequency changes.
Study on probabilistic safety assessment in decommissioning of nuclear power plant
Authors: Wang Handing , Liang Xiaoyu
Published: April 2023

The decommissioning of Nuclear power plant involves many activities different from the normal operation stage of Nuclear power plant. In the process of decommissioning, there are many new safety problems, which usually require new safety evaluation. The safety management of decommissioning runs through the whole decommissioning stage until the decommissioning of the plant site is completed. The management level depends on the risk level of each stage of decommissioning, especially the decommissioning process of high radioactivity in nuclear power plant, so it is necessary to pay attention to the risk of different stages of decommissioning and improve the decommissioning safety management. At present, probabilistic safety assessment method has become an effective tool to support and supplement deterministic safety assessment, and is used in regulatory activities. The safety risk analysis of nuclear power plant in the decommissioning stage in China is in the initial stage, with little experience. Therefore, it is necessary to study the corresponding technical methods and risk management applications. This paper study on the probabilistic safety assessment in the decommissioning of nuclear power plant, including its scope of application, risk-informed assessment method and safety management application. The probabilistic safety assessment of decommissioning of nuclear power plant is an effective means to evaluate the potential risks related to decommissioning activities and their possible consequences. This method can be used for safety review and safety management in the decommissioning stage of nuclear power plant.
Study on fuel cold energy utilization of large ammonia powered ship
Authors: Zhang Gang , Liu Zhu , Zhang Xiaorong , Yang Yongjian
Published: April 2023

Taking large ammonia powered container ship as the research object, a set of liquid ammonia cold energy cascade comprehensive utilization system is designed. The system mainly includes low temperature cargo hold system, high temperature cargo hold system and marine air conditioning system. Aspen HYSYS software is used to simulate the system scheme. Based on the utilization rate of cold energy in the low temperature cargo hold system, the maximum of liquid ammonia flow fraction under different operating conditions was determined, and the cold energy utilization system exergy efficiency was calculated. In the 75% working condition of the ship, when the flow fraction was 40%, the whole cold energy utilization system exergy efficiency was 34.42%, in this way, the effective utilization of liquid ammonia cold energy is realized.
Implementation of ocean element curves and profiles on GIS
Authors: Zhang Zengjian , Xu Shanshan , Geng Shanshan , Wang Kaiyue , Chen Fei , Ning Pengfei
Published: April 2023

This paper introduces the realization algorithm of ocean element curves and profiles on GIS. The algorithm projects the curves and profiles of ocean elements onto the geographic map. It realizes the combination of two-dimensional spatial geographic location, time dimension of curve change and spatial dimension of vertical profile, and displays three-dimensional information on a two-dimensional plane map. It can well express the actual survey data, statistical analysis data, and realize the comprehensive visualization of marine elements. The algorithm is useful in the visualization of ocean data. The algorithm has good application prospects in the visualization display of marine data, quality control of survey data, joint analysis of different elements or disciplines, and scientific research.