bluuebunny/crossref_metadata_2025 huggingface dataset:
6D pose estimation of object based on fused region-level feature in cluttered scenes
Authors: Liu Xiangpeng , Duanmu Huiping , An Kang , Wang Wancheng , Song Yaqing , Gu Qingying , Yuan Bo , Wang Danning
Published: March 2023

RGB-based methods have certain disadvantages because they lack 3D information and cannot cope with the pose estimation problem in cluttered scenes. Therefore, we propose a region-level pose estimation network that uses RGB-D images. We first extracted the objects’ color features and geometric features by convolutional neural networks (CNN) and PointNet, respectively, and then performed feature fusion. The fused features were fed into a region-level feature extraction network to obtain the region-level features, which extracted the local geometry features from the point cloud and learned the point set’s semantic information. We used the output of the region-level feature extraction network to perform region-level pose estimation, then selected the pose with the highest confidence level as the output and iteratively optimized the pose to obtain the final results. The experimental results showed that the proposed solution performed well on the LINEMOD data set, which verified the effectiveness of the proposed method in the pose estimation problem and the algorithm’s robustness in severely cluttered scenes.
Global well-posedness of slightly supercritical SQG equations and gradient estimate
Authors: Choi Hyungjun
Published: March 2023

We prove the global regularity of smooth solutions for a dissipative surface quasi-geostrophic (SQG) equation with both velocity and dissipation logarithmically supercritical compared to the critical equation. By this, we mean that a symbol defined as a power of logarithm is added to both velocity and dissipation terms to penalize the equation’s criticality. Our primary tool is the nonlinear maximum principle which provides transparent proofs of global regularity for nonlinear dissipative equations. Combining the nonlinear maximum principle with a modulus of continuity, we prove an uniform-in-time gradient estimate for the critical and slightly supercritical SQG equation. It improves the previous double exponential bound by Kiselev–Nazarov–Volberg to the single exponential. In addition, we prove the eventual exponential decay of the solutions.
Impact of respiratory motion on proton pencil beam scanning FLASH radiotherapy: an in silico and phantom measurement study
Authors: Yang Yunjie , Kang Minglei , Huang Sheng , Chen Chin-Cheng , Tsai Pingfang , Hu Lei , Yu Francis , Hajj Carla , Choi J Isabelle , Tome Wolfgang A , Simone Charles B , Lin Haibo
Published: March 2023

Objective. To investigate the effects of respiratory motion on the delivered dose in the context of proton pencil beam scanning (PBS) transmission FLASH radiotherapy (FLASH-RT) by simulation and phantom measurements.Approach. An in-house simulation code was employed to performin silicosimulation of 2D dose distributions for clinically relevant proton PBS transmission FLASH-RT treatments. A moving simulation grid was introduced to investigate the impacts of various respiratory motion and treatment delivery parameters on the dynamic PBS dose delivery. A strip-ionization chamber array detector and an IROC motion platform were employed to perform phantom measurements of the 2D dose distribution for treatment fields similar to those used for simulation.Main results. Clinically relevant respiratory motion and treatment delivery parameters resulted in degradation of the delivered dose compared to the static delivery as translation and distortion. Simulation showed that the gamma passing rates (2 mm/2% criterion) and target coverage could drop below 50% and 80%, respectively, for certain scenarios if no mitigation strategy was used. The gamma passing rates and target coverage could be restored to more than 95% and 98%, respectively, for short beams delivered at the maximal inhalation or exhalation phase. The simulation results were qualitatively confirmed in phantom measurements with the motion platform.Significance. Respiratory motion could cause dose quality degradation in a clinically relevant proton PBS transmission FLASH-RT treatment if no mitigation strategy is employed, or if an adequate margin is not given to the target. Besides breath-hold, gated delivery can be an alternative motion management strategy to ensure high consistency of the delivered dose while maintaining minimal dose to the surrounding normal tissues. To the best of our knowledge, this is the first study on motion impacts in the context of proton transmission FLASH radiotherapy.
Validation of Monte Carlo simulated absorbed-dose-to-water inside a custom SPECT/CT phantom using active and passive dosimeters: a feasibility study using 99mTc
Authors: Bertinetti Andrew , Rodrigues Miesher , Palmer Benjamin , Garcia Timothy R , Vija A Hans , Culberson Wesley
Published: March 2023

Objective.This project aims to provide a novel method for performing dosimetry measurements on TRT radionuclides using a custom-made SPECT/CT compatible phantom, common active and passive detectors, and Monte Carlo simulations. In this work we present a feasibility study using 99mTc for a novel approach to obtaining reproducible measurements of absorbed-dose-to-water from radionuclide solutions using active and passive detectors in a custom phantom for the purpose of benchmarking Monte Carlo-based absorbed-dose-to-water estimates. Approach. A cylindrical, acrylic SPECT/CT compatible phantom capable of housing an IBA EFD diode, SNC600c Farmer type ion chamber, and TLD-100 microcubes was designed and built for the purpose of assessing internal absorbed-dose-to-water at various points within a solution of 99mTc. The phantom is equipped with removable inserts that allow for numerous detector configurations and is designed to be used for verification of SPECT/CT-based absorbed-dose estimates with traceable detector measurements at multiple locations. Three experiments were conducted with exposure times ranging from 11 to 21 h with starting activities of approximately 10–16 GBq. Measurement data was compared to Monte Carlo simulations using the egs_chamber user code in EGSnrc 2019. Main results. In general, the ionization chamber measurements agreed with the Monte Carlo simulations within k = 1 uncertainty values (±4% and ±7%, respectively). Measurements from the TLDs yielded results within k = 1 agreement of the MC prediction (±6% and ±5%, respectively). Agreement within k = 1 uncertainty (±6% and ±7%, respectively) was obtained for the diode for one of three conducted experiments. Significance. While relatively large uncertainties remain, the agreement between measured and simulated absorbed-doses provides proof of principal that dosimetry of radionuclide solutions with active detectors may be performed using this type of phantom with potential modifications for beta-emitting radionuclides to be introduced in future work.
Numerical experiments on the total D–D fusion neutron yield versus deuterium pressure for different energy plasma focus devices using the Lee model code
Authors: Wahbe S , Abou-Ali Y , Akel M , Lee S , Marciniak L
Published: March 2023

Numerical experiments using the Lee model code were carried out to compute the total D–D fusion neutron yield versus initial deuterium pressure for nine different plasma focus devices [PF50, AACS, PF400J, PF2.2, UNU-ICTP, PFZ200, PF24, PF78, Poseidon]. The computed data were compared with the published experimental results. In addition, the maximum discharge current, the pinch current and the pinch ion number density, as a function of initial deuterium pressure, were discussed, as well as their effect on the neutron yield. The optimum pressures that correspond to the maximum neutron yield Y
n were obtained for all considered devices, with reference to the specific plasma focus properties. The scaling laws for the D–D fusion neutron production, in terms of storage energies E
0 and pinch current I
pinch, were derived. The scaling of Y
n with I
pinch and E
0 over the whole range of investigated energies up to 300 kJ has been obtained as follows:

Y

n

∼

I

pinch

5

,

 

Y

n

∼

E
0

1.95

. These laws are important in the planning and design of a plasma focus as a potentially powerful pulse neutron source.
Demonstration of p-GaN/AlGaN/GaN-based ultraviolet phototransistors with sub-saturated transfer characteristics
Authors: Chen Dingbo , Zhang Penghao , Wang Luyu , Huang Wei
Published: March 2023

We report ultraviolet phototransistors (UVPTs) based on p-GaN/AlGaN/GaN high-electron-mobility transistors (HEMTs). Thanks to the effective depletion of the two-dimensional electron gas by the p-GaN layer, a dark current as low as 5.2 × 10−10A mm−1 was achieved. Moreover, a unique sub-saturated region can be formed in the transfer curve of the UVPTs due to the special photogenerated electric field in the heterostructure, which endows the device with a large photo-to-dark current ratio over 105. In particular, responsivity up to 1.3 × 108 and 6.1 × 103 A W−1 was demonstrated at gate voltage of 5 and 0.68 V, respectively. The minimum rise time and fall time of the device transient response were measured to be around 1.8 ms and 8.8 ms, respectively. This work shows great UV detection potential of the p-GaN/AlGaN/GaN HEMTs, which opens up possibilities of realizing multifunctional enhancement HEMTs for future III–V photonic integrated devices and systems.
A hybrid FCN-BiGRU with transfer learning for low-velocity impact identification on aircraft structure
Authors: Huang Chenhui , Liao Weilin , Sun Hu , Wang Yishou , Qing Xinlin
Published: March 2023

In the work process of an aircraft, its external structure frequently encounters some low-velocity impact events, resulting in some barely visible impact damages inside the structure. Therefore, impact localization and reconstruction are critical for the structure’s health monitoring and reliability analysis. However, traditional inversion methods usually perform poorly in identifying random impact loads due to a series of problems. Inspired by the superior model properties of deep learning algorithms, a novel feature learning-based technique for impact load reconstruction and localization is presented. The proposed method consists of two parts, the first of which is utilized to localize the impact loads and is referred to as one-dimensional full convolution network. The other part aims at reconstructing the impact load and is called attention mechanism-full convolutional network-bidirectional gating recurrent unit-multilayer perceptron. Moreover, a transfer learning technique is introduced to optimize the model structure and process in light of the suggested innovative network model. The experimental piece of this research was an aircraft cutting segment whose structural surface was equipped with a number of piezoelectric sensors. These sensors received impact response signals with differences in amplitude from hammer strikes at various positions. In the work, the process of locating first and then reconstructing the impact load history was followed. And the influence of implementing the transfer learning mechanism on the performance of the impact load history reconstruction model was investigated as well. Three experiments and repeated cross-validation verified the efficacy of the proposed method. The findings indicated that the proposed technique could accurately and quickly detect impact loads at various locations. Simultaneously, it also allowed a perfect reconstruction of the impact loads of different impact energies.
CrackDiffusion: crack inpainting with denoising diffusion models and crack segmentation perceptual score
Authors: Chen Lizhou , Zhou Luoyu , Li Lei , Luo Mingzhang
Published: March 2023

Cracks commonly occur in engineering structures. Imaging method is one of the most effective detection method for crack. However, crack information captured by the imaging sensors is often interfered by noise and the other environmental factors. In this paper, we propose a crack inpainting method that can automatically repair the missing crack information. The inpainting method consists of a denoising diffusion model and a segmentation guidance model. Taking advantages of denoising diffusion model’s stability and segmentation guidance model’s accuracy, we can achieve coherent inpainting patches as well as accurate crack traces. Furthermore, we propose a fine crack metric—crack segmentation perceptual score to guide high quality crack generation. Experimental results show that our method achieves both high quality and precise crack inpainting results, which is very beneficial to the crack detection and evaluation in structural health monitoring.
Quantum generative adversarial imitation learning
Authors: Xiao Tailong , Huang Jingzheng , Li Hongjing , Fan Jianping , Zeng Guihua
Published: March 2023

Investigating quantum advantage in the NISQ era is a challenging problem whereas quantum machine learning becomes the most promising application that can be resorted to. However, no proposal has been investigated for arguably challenging inverse reinforcement learning to demonstrate the potential advantage. In this work, we propose a hybrid quantum–classical inverse reinforcement learning algorithm based on the variational quantum circuit with the generative adversarial framework. We find an important connection between the quantum gradient anomaly and the performance degradation, which suggest a gradient clipping strategy to stabilize the training process. In light of the algorithm, we study three classic control problems and the Hamiltonian parameter estimation in quantum sensing with shallow quantum circuits. The numerical results showcase that the control-enhanced quantum sensor can saturate quantum Cramér-Rao bound only with a single variational layer, empirically demonstrating a parameter complexity advantage over the classical learning control. The proposed generative adversarial reinforcement learning algorithm achieves state-of-the-art performance in classical and quantum sensor control in terms of required number of parameters.
Spatiotemporally controllable honeycomb superlattice plasma photonic crystals in dielectric barrier discharge
Authors: Fan Weili , Hou Xiaohan , Jia Mengmeng , Tian Miao , He Yafeng , Liu Fucheng
Published: March 2023

We present the experimental realization of tunable honeycomb superlattice plasma photonic crystals (PPCs) in dielectric barrier discharge by utilizing mesh-liquid electrodes. Fast reconfiguration among the simple honeycomb lattice, honeycomb superlattice, and honeycomb-snowflake superlattice is achieved. A dynamic control on the sizes of center scattering elements in the honeycomb superlattice has been realized. A phenomenological activator-inhibitor reaction diffusion model is established to demonstrate the formation and reconstruction of the honeycomb superlattice. The simulations reproduce well the experimental observations. The photonic band diagrams of different honeycomb PPCs are studied by using the finite element method. The addition of large center elements in honeycomb superlattice yields remarkable omnidirectional band gaps that are about 2.5 times larger than in the simple honeycomb lattice. We propose an effective scheme to fabricate spatiotemporally controllable honeycomb lattices that enable great improvement in band gap size and dynamic control of microwave radiations for wide applications.
From a wide band gap to the superconducting proximity effect: Fe on Pb(111)
Authors: Omidian M , Brand J , Néel N , Crampin S , Kröger J
Published: March 2023

Epitaxially grown Fe nanostructures on Pb(111) were studied by low-temperature scanning tunneling microscopy and spectroscopy. The deposited Fe assemblies are classified into two groups according to their electronic behavior close to the Fermi energy. One group exhibits a wide energy gap of 0.7 eV that is independent of the temperature ranging from 5 K to room temperature. These Fe islands indicate the absence of the superconductivity proximity effect in their interior. The other group shows a metallic behavior at the Fermi level. The substrate superconducting phase locally enters into these islands, which is evidenced by a sharp resonance at the Fermi energy presumably signaling Andreev reflection at the magnet–superconductor interface.
Bulk electronic structure of Mn2NiGa using hard x-ray photoelectron spectroscopy and density functional theory
Authors: Sadhukhan Pampa , Sarkar Shuvam , D’Souza Sunil Wilfred , Gloskovskii Andrei , Roy Barman Sudipta
Published: March 2023

Mn2NiGa is a potential magnetic shape memory alloy with austenite to the martensite phase transition. Here, we have investigated the bulk electronic structure of Mn2NiGa in the austenite and martensite phases studying its valence band using hard x-ray photoelectron spectroscopy (HAXPES). In the austenite phase, we observe a wide (≈10 eV) valence band (VB) spectrum with several prominent features. In order to explain the HAXPES VB spectra, we have compared our experimental VB spectra with the theoretical VB calculated using the partial density of states from our existing density functional theory (DFT) calculations. The shape of the experimental VB and energy positions of all features are in excellent agreement with the calculated VB and we find that the former is dominated by Ni 3d as well as 4s states of Mn, Ni, and Ga. An important observation is that experimental VB combined with the DFT-based VB calculation establishes the prevalence of the anti-site disorder in Mn2NiGa. Compared to the austenite phase, in the martensite phase, the VB shows a marginal decrease in the density of states around −0.5 eV below the Fermi level (E

F
), and the main peak is slightly shifted towards E

F
. These experimental observations have been explained by considering the tetragonally distorted structure with the anti-site disorder in the martensite phase.
An iterative method for simultaneous reduction on beam-hardening and scatter artifacts in x-ray CT
Authors: Xia Dimeng , Zhao Shusen , Zhang Huitao , Zhu Yining , Zhao Xing , Zhang Peng
Published: March 2023

Beam-hardening and scatter are two significant factors leading to contrast reduction and gray value inaccuracy in CT images. The cupping artifacts and obscure boundaries in reconstructed images are also caused mainly by both beam-hardening and scattering. It is difficult to get high-quality CT images with only one of them to make correction. In this paper, we proposed an x-ray CT polychromatic attenuation model with scatter effect, and an iterative method for simultaneous reduction on beam-hardening and scatter artifacts. In this model, the measurements of the detector comprise two parts: an attenuation term and a scatter term. The former is defined by an exponential rational fraction to fit the traditional attenuation process, and the latter is defined by a convolutional scatter intensity. The coefficients of the rational fraction in the attenuation term and the scatter term kernel are all calculated from a calibration phantom which is scanned to get corresponding equations. Based on the polychromatic attenuation model, we proposed an iterative artifacts reduction method combining deconvolution technique with linearized back-projection (iDLB method). This method makes the nonlinear polychromatic attenuation model become easily solvable by linearizing transformation, which simplifies the residuals allocation process. Experiments of both numerical simulation and practical data show the iDLB method has the ability to reduce beam-hardening and scatter artifacts simultaneously, improve the contrast of CT images, and it is highly parallelized for lower computational cost.
Extreme heatwave over Eastern China in summer 2022: the role of three oceans and local soil moisture feedback
Authors: Jiang Jilan , Liu Yimin , Mao Jiangyu , Wu Guoxiong
Published: March 2023

Eastern China experienced persistent regional extreme heatwaves in the summer of 2022, with disparate spatial features and formation mechanisms in different months. We quantitatively assessed the relative contributions of three oceans, i.e. tropical Indian Ocean and Pacific and North Atlantic, and the local soil moisture–temperature feedback using linear regression. The results showed that the monthly mean atmospheric circulation anomalies failed to explain the extreme heatwave in June 2022. The combined contribution of the tropical Indo-Pacific and North Atlantic sea surface temperature anomalies (SSTAs), together with the local soil moisture–temperature feedback, explaining approximately 10% of the temperature anomalies. In July, the tropical Indo-Pacific SSTAs promoted anomalous atmospheric circulation and extreme heat via meridional circulation originating in the Maritime Continent, accounting for approximately 10% of the temperature anomalies, with North Atlantic SSTAs contributing the same percentage by a mid-latitude steady Rossby wave. Local soil moisture–temperature feedback accounted for 42% of the anomalies. The tropical Indo-Pacific SSTAs produced a strong western North Pacific anticyclone in August, but their direct contribution to the temperature anomalies was negligible. The North Atlantic SSTAs contributed 9% of the total via the mid-latitude steady Rossby wave. Local soil moisture–temperature feedback contributed 66%, suggesting that the July heatwave and drought exerted a significant impact on the subsequent August extreme heatwave. Global warming has greatly facilitated extreme heatwaves, accounting for about 30%–40% of these events in summer 2022. These results also suggest that the climatic effects of tropical Indo-Pacific and North Atlantic SSTAs on Eastern China are evident in the month-to-month variation in summer. Our results thus contribute to the understanding and prediction of extreme heatwaves in Eastern China.
Opportunities and prospects for the use of solar energy for refrigeration of public buildings
Authors: Izzatillaev J , Alimova L , Usmonov N , Alijanov D
Published: March 2023

This paper describes the calculation of evaporative-radiant cooling of recycled water in summer air-conditioning systems. A differential equation for the heat balance of water flowing down an inclined plane is derived. As one possible way of increasing the efficiency of air conditioning systems based on cooling water by adiabatic evaporation in the air flow the use of night-time evaporative cooling of the water, followed by daytime cooling in insulated storage tanks. The temperature of the water chilled in this way is 3-4 °C lower than the temperature of the water chilled during the day, and the final water temperature is close to the saturation temperature of the outside air. The equations for calculation of mass transfer coefficients, radiation and heat transfer coefficient of an insulated bottom of an evaporative-radiant water-cooling unit are given. Based on the Mathcad program and the result of the calculation, the dependence of the final water temperature on the initial water temperature is obtained. As a result of the calculation, the specific heat capacity of the evaporative radiant water-cooling unit for the production of free cooling is determined.
Application of ozone electrodispersion technology for disinfection of water
Authors: Babayev A , Tasheva U , Allenova I , Sanbetova A T
Published: March 2023

This article provides definitions of the positive and negative effects of the use of chlorine and ozone in water disinfection and presents the methodology and results of experimental studies of the parameters of water treatment with ozone, the electrodispersion method, as well as the electrode system “potential plane with corona needles - grounded plane”. The parameters of water treatment modes were determined by the method of three variants of aerosol charge, negative, positive and bipolar. The parameters of water treatment with ozone determined on the basis of these studies were verified on the basis of experimental studies of the process of ozone effects on aerosol particles in the contact chamber. The methodology and analysis of the results of these studies are given. Based on these studies, the best ratios of the parameters of water flow, air velocity and electrical voltage were determined. The best disinfection result was determined by the charge polarities of the water aerosol.
Corona discharge ozonizers with vacuum coatings and their use for processing agricultural products
Authors: Parpiyev M P , Simonov A A , Kamardin A I , Kh Abdurakhmanov O
Published: March 2023

At present the majority of ozonizers in the world are manufactured on the basis of a barrier discharge. But the special ceramic electrodes used for such ozonizers are highly sensitive to humidity and pollution of the air supplied to the device. Typically, these devices use cartridges to filter and dehumidify the air. In this research, corona discharge ozone generators were used due to sufficient energy efficiency and ease of implementation of this method of ozone synthesis from oxygen-containing gases. The results showed that that coatings with a thickness of up to 3-5 μm made it possible to create a layer on the electrode surface that protects against oxidation or has a conductive oxide that maintains the operability of the point electrode. Furthermore, In the system of electrodes of the point-plane type, a voltage of positive polarity was applied to the point electrode. The initial voltage applied to the discharge gap was 14–15 kV. As the surface properties of the samples changed, the voltage had to be reduced to avoid spark breakdown.
The influence of the impact of electrical impulses on the juice outputting of the pulp
Authors: Eshpulatov N , Khalmuradov T , Rakhimov F , Abdurayimov S , Khurramov A , Mullajonov I , Vorisova R
Published: March 2023

In this article was applied a comprehensive research method which made it possible to quite fully investigate the mechanism of the effect of electrical impulses on the protoplasm of cells and determine the optimal parameters of such effect on plant raw materials, ensuring high efficiency of their use to increase the juice yield. The complex research method made it possible to obtain the necessary data for the implementation of the electrical method for intensifying the process of extracting juice from plant materials. Due to the fact that the issues related to the use of electrical impulses for the processing of plant materials have been little studied and there is no sufficiently clear understanding of the mechanism of such an effect on living cells, we made an attempt to investigate the mechanism of this process. A technique has been developed for studying the dynamics of the action of electric current on plant tissue cells. We expressed the yield of juice from raw materials as a percentage of the weight of the pulp, which was processed and pressed. Thus, a comparison of the results of individual experiments showed an absolute increase in juice yield as a percentage.
Development and testing of a laboratory model of a two-turbine small hydroelectric power plant
Authors: Davirov A , Kodirov D , Tukhtaeva R , Ibragimov I , Urokova N
Published: March 2023

This article considers the main methods of regulating water consumption and power of micro hydroelectric power plants. New technical solutions for screw jet turbines adapted to low pressures and water flow rates are proposed. The Archimede’s screw turbine is a cost-effective and environmentally friendly microhydropower technology that operates at high efficiency at low pressure and medium flow rates. In this case, the change in power depends on the following parameters: the number of blades, water flow, the angle of inclination of the blades and the height of the pressure. Preliminary calculations carried out by the authors show that the power of a microhydroelectric power station depends on individual factors of the area. With an increase in the speed of the water flow, the speed of the water wheel also increases, and in turn, the electric power of the microhydroelectric power station increases.
Flow stabilization and pulsation in external channels in fuel engines
Authors: Musabekov Z , Khakimov J , Yangiboev A , Tairova N , Usmonov J , Petruchenko A
Published: March 2023

A turbocharger installed in the gas exchange system of a reciprocating internal combustion engine has a significant impact on the gas-dynamic and thermophysical characteristics of the exhaust process. When installing a turbocharger in a discharge system, there is the possibility of mitigating local pulsations of flow rate and pressure in the discharge pipe. The use of such an exhaust system increases the output capacity of the piston fuel engines outlet pipeline by approximately 20%, which also has a positive effect on the performance of individual systems and units such as the turbocompressor and exhaust manifold and reduces the temperature stress of the engine exhaust system and turbocompressor turbine elements.
Study on determination of an asynchronous motor’s reactive power by the current-to-voltage converter
Authors: Karimjonov D D , Siddikov I X , Azamov S S , Uzakov R
Published: March 2023

This article presents a method for determining the primary currents, non-sinusoidal and asymmetrical currents flowing through the stator windings of an asynchronous motor based on the signal in the form of the output voltage from the current converter loops placed in each phase between the poles of the asynchronous motor stator and in the arrangement of the stator windings. Differences and characteristics of output signals are researched based on independent, series and opposite (bifilar) connection schemes of asynchronous motor current converter loops of measuring coil. In order to determine the value of the currents generated in each phase of the asynchronous motor stator windings, the output signals of the current converter with independent loop and loops connected in series were mutually analyzed. Measuring non-sinusoidal and asymmetrical currents, according to the opposite (bifilar) connection scheme, the loops of measuring coils are placed in the inter-pole grooves of each phase of the stator in the order corresponding to the three-phase stator windings, the current converter measuring coils each consists of two loops, bifilarly connected to each other. The end of loops of the measuring coils has two exits. Diodes and phase meter-regulators are placed on the first outputs of the loops, and they are oppositely connected to the microprocessor unit for measuring and controlling the asymmetry. The second outputs of the loops are connected directly opposite to the microprocessor unit for measuring and controlling non-sinusoidal currents. This type of current converter is important for determining the non-sinusoidal and asymmetrical currents generated in asynchronous motors, it increases the functional capabilities and accuracy of the current converter, and based on the determined results, it simplifies theoretical calculations, and at the same time, the dynamic and it will be possible to determine the static characteristics through theoretical differential equations. As a result of the research, practical and theoretical results were compared.
Study on application of electrohydraulic effect for disinfection and increase of water nutrient content for plants
Authors: Turdiboyev A , Aytbaev N , Mamutov M , Tursunov A , Toshev T , Kurbonov N
Published: March 2023

This article describes the application of electrohydraulic effect to decontaminate wastewater and increase nutrient content in water for agricultural crops. It is characterized by the formation of chemical processes in water and electrohydraulic effect carried out using ultrasound and ultraviolet radiation. The nutrient content in water has increased from 1.1 mg/l to 2.23 mg/l, i.e. it has gone up by 102.7% after the preliminary water treatment by means of the electrohydraulic effect, while neutralization of coliform bacteria in the treated water has decreased from 3474 (RLU) to 610 (RLU), i.e. it has dropped to 82.55 over control. The increase of nutrient chemicals in water and coliform bacteria neutralization (Escherichia coli) depend on the treatment time, discharge voltage, capacitor capacity, discharge interval and the number of pulses if treated with electrohydraulic effect conducted by means of ultrasound and ultraviolet radiation causing a chemical reaction of electrohydraulic shock in water. The discharge voltage for increase is 9-15 kV, disinfection time - 100-120 minutes depending on the voltage of treatment. It is advisable to have the capacitor capacity of 0.8 μF and discharge interval of 10-12 mm.
Studying on thermal processes during the motion of combustion products in the gas chimneys of the heat power plant
Authors: Anarbaev A , Kodirov D , Khushiev S , Izzatillaev J , Isakov A , Berdiyorov T , Shukuraliev A , Normuminov J
Published: March 2023

This article discusses the new in Uzbekistan heat recovery technology is leaving the flue gas from boilers. This is achieved by condensation of water vapor therein. An analysis of the advantages and disadvantages of contact heat recovery and surface types. The analysis of the heat transfer coefficients in the condensing heat exchanger surface. The temperature regimes which provide point of the flue gas dew point. The limited stresses in the chimney of the boiler unit are calculated using condensing heat utilizers of the exhaust gas for stations of Uzbekistan.
Method development for determining the energy-efficient mode of air-cooling devices’ operation
Authors: Kh Khoshimov U , Khushiev S
Published: March 2023

When ensuring the normative limit of the heat of the gas transmitted to the main gas pipelines by means of air cooling devices of the gas transmission compressor station, the modes of parallel operation of the fan motors of the air cooling device system are considered. At the same time, a comparison was made of methods for adapting air cooling devices to factors affecting energy-efficient operating modes. As a result, based on a mathematical model of the combustion operating mode through a gas-air cooling device, the possibility of regulating the engine speed and increasing the energy efficiency of the system, taking into account seasonal and temperature changes, is shown. The main parameters for saving energy sources are introduced into the technological processes of gas compression and cooling.
Experience of using solar energy in water lifting systems: A case study of Uzbekistan
Authors: Mirzabaev A , Isakov A , Mirzaev A , Buranov O , Sulaymanov J
Published: March 2023

This article discusses modern schemes of using solar energy in the systems of the Ministry of Water Management. The analysis of electricity generation by photovoltaic water-lifting stations by months has been carried out and the effectiveness of their use as a reliable source of power supply to pumps has been proved. The payback period of solar water lifting systems is calculated. Calculations show that the payback period for solar water-lifting systems, considering only the cost of saved natural gas and carbon dioxide emissions is no more than 6 years. It should be noted that the life of the PVP is more than 20 years. Tax breaks on property and land use, provided for by the legislation of the Republic of Uzbekistan, further shorten the payback period.
Electrophysical processes in an electroterminator (with an intelligent system) with sliding contacts in the power circuit
Authors: Denmukhammadiev A , Mukhammadiev A , Kucharov F , Pardaev A
Published: March 2023

This article presents data on the properties of sliding contacts during the rotation of the axis of a device for pre-sowing treatment of crop seeds, considers the issues of automation of intermittent power supply and measurement of electrical conductivity and temperature parameters of seed material in the process of electrotechnology. At the same time, the contact resistance of the power circuit, normalized moistening of sowing seeds, depending on the type of plants, was taken as the basis of the physical model. Smart system takes into account soil parameters (type, density, moisture content). In the initial period of seed treatment, moisture penetrates into the seed from the outside. therefore, the time of humidification and electrical treatment are the main factors. Depending on the seed variety, it will be possible to change the operating parameters of the electrical treatment of crop seeds. The work also carried out a review of the literature and mathematical calculations.
Effect of temperature on the kinetics of the process of nitric acid decomposition of Arvaten serpentinite
Authors: Ahmadjonov A , Alimov U , Tuychi P , Seitnazarov A , Reimov A , Namazov Sh , Sadullayev S
Published: March 2023

The process of decomposition of serpentinite from the Arvaten deposit (Uzbekistan) with 30% nitric acid at its stoichiometric norm of 100% and temperatures of 313, 323, 333, 343 and 353 K for 120 min was studied in this work. It has been established that with increasing temperature, the decomposition coefficient (Cdec.) of MgO, Fe2O3 and Al2O3 increases from 11.48 to 82.5%; from 13.96 to 41.49% and from 38.87 to 96.61%, respectively. Meaning Cdec. iron oxide in the form of magnetite is relatively low than other components. Cdec. made it possible to reveal the rate constant of decomposition of serpentinite in nitric acid at the above temperatures. The rate of decomposition of the raw material is apparently limited by the diffusion of the layer of amorphous silica particles on the surface of the raw material. Depending on the temperature (313-353 K), the value of the apparent activation energy (Ea) of the Arvaten serpentinite lies from 21.79 to 7.53 kcal/mole or from 91.21 to 31.53 kJ/mole, and the average value (Eaver.) is 14.226 kcal/mole and 59.68 kJ/mole, respectively. It turned out that the data are similar to other serpentinite deposits. That is, Arvaten serpentinite is reactive towards nitric acid.
Experimental investigation of solar powered refrigerator in Uzbekistan climate
Authors: Abdullaev N A , Axaopoulos P J , Sakellariou E I , Sh Shaislamov A , Juraev R R
Published: March 2023

The energetic performance of autonomous solar powered refrigerator is analyzed. In this refrigerator, the solar energy is converted into electrical energy by a photovoltaic (PV) array, then the generated electrical energy is used to power a vapor – compression system which produces cooling energy at its evaporator. The evaporator is sunk to the water so that produced cooling energy is used to formation water ice, thus accumulates cooling energy in the form of ice. While, compressor is working during the daylight hours, cooling energy is produced. During the night, the cooling energy comes from latent heat of fusion of ice which is collected in day time. The results of experiments showed that not only the solar energy has influence on the energetic performance of solar refrigerator but ambient temperature is also crucial factor in this case.
Analysis of ionic equilibria by water treatment stage and calculation of monitored parameters
Authors: Kh Mukhtarov F
Published: March 2023

The mathematical model of the unit of the water treatment scheme is based on the mathematical model of improvements in the consistency metrics by step of treatment and is the basis for the technical measurement of this element. The suggested step-by-stage estimation of the water quality indicators for the assembled water treatment unit system helps the final quality of the treated water to be calculated and the mathematical model of the quality indicators adjustment by treatment phase was developed in relation to the water used in the TPP water treatment. For circuit elements, the change in the input and output quality indicators occurs depending on the type of processing, which is conveniently represented by equivalent circuits. For circuit elements, input and output quality variation occurs depending on the type of processing, which is conveniently represented by equivalent circuits. Thus, an equivalent scheme for the change in quality indicators by treatment stage can be represented by the example of a one-stage chemical desalination scheme for natural water. It should be noted that the calculated concentration fractions of carbon dioxide dissociation forms and known carbonate hardness, for example, can be used to determine the concentrations themselves.
Analysis of existing problems of ensuring traffic safety in major cities of Uzbekistan
Authors: Abdunazarov J , Shukurov I , Nishonov A , Shaumarov S
Published: March 2023

This article is devoted to the analysis of road traffic accidents and road safety in large cities of the Republic of Uzbekistan such as Bukhara, Fergana and Samarkand. And also, statistical data of road traffic accidents are processed throughout the republic. Such factors as transport risk, social risk and severity of the consequences of a road traffic accident have been identified. In conclusion, the author’s opinion on the factors affecting road safety in the republic is presented.
Effect of irrigation procedures on yield and oil concentration of peanut
Authors: Khudaykulov J , Umarova Z , Buriev I , Irnazarov Sh , Rasulov I , Jong Y
Published: March 2023

Peanut grasses are less demanding to moisture from formation to flowering and therefore one watering is sufficient during this period. Soil moisture LFMC from flowering to ripening should not be less than 70% and the rate of irrigation should be 700-1000 m3/ha. The seasonal irrigation norm is 4000-5000 m3/ha. The number of irrigations during the growing season is 4-5. During the growing season of peanuts, the crop is kept free from weeds, weeding, loosening of row spacing and formation of soil around the bush when gynophores are formed. The purpose of the study was to select fast-ripening, high-yielding foreign peanut varieties and samples suitable for the conditions of typical gray soils of Tashkent province in Uzbekistan, optimal planting times of local varieties, feeding standards with mineral fertilizers, irrigation regime and biostimulator application technology and scientifically substantiate its impact on the level of fatness. The increase in the number and rate of irrigation of peanuts has a positive effect on the acceleration of its physiological processes and the prolongation of the growing season. When the irrigation of the “Salomat” variety was carried out in the order of 70-75-65% compared to the LFMC, the ripening period was extended by 7-10 days and amounted to 165-167 days. Irrigation of “Salomat” variety was carried out in the order of 70-75-65% compared to LFMC, with the application of mineral fertilizers in the amount of N200P150K100 kg/ha, the yield of legumes was 29.6 q/ha, in “Mumtoz” variety - 34.0 q/ha.
Study of microelement containing nitrogen fertilizers based on spent lithium-ion battery
Authors: Fazilova M , Hasanov Sh , Alimov U , Raxmanova M , Sadullaev S
Published: March 2023

Ammonium nitrate is a hygroscopic and caking product for growing agricultural products. In order to improve the properties of ammonium nitrate, the composition of the calcined and crushed cathode material from the used lithium ion battery was studied. Since the cathode material mainly consists of lithium, cobalt, manganese and nickel, it has been adopted as a polymicroelement-containing additive to improve the composition and properties of ammonium nitrate. Studies have shown that the introduction of cathode powder into the ammonium nitrate melt in the amount of 0.5-3.0 g in relation to 100 g of ammonium nitrate led to an increase in trace elements such as lithium, cobalt, manganese and nickel from 0.0094 to 0.0527; from 0.0561 to 0.2395; 0.0387 to 0.2860 and from 0.0112 to 0.0387%, respectively. The microelement containing nitrogen fertilizers obtained in this way have a significant digestibility of 2% citric acid, 0.2M Trilon B and an aqueous form. The static strength of the granules of the obtained trace-containing nitrogen fertilizers ranges from 4.62 to 6.13 MPa, which is 3.40-4.51 and 2.85-3.78 times greater than pure and industrial ammonium nitrate. High values of fertilizer strength contributed to an increase in the dissolution rate of granules of new types of nitrogen fertilizers from 71 to 87 sec. This suggests that the obtained microelement containing nitrogen fertilizers, according to the established values of the dissolution rate, will be leached out of the soil 1.6–2.0 and 1.5–1.9 times slower, respectively, than pure and industrial ammonium nitrate.
Dynamics of the number of microorganisms distributed in irrigated typical soil and grass soils by seasons
Authors: Burkhanova D , Urmanova M , Shadieva N , Usmanova M
Published: March 2023

Biological preparations developed on the basis of biological methods have been considered the mainstay in the protection and fight against various diseases occurring in plants. It has been proven that the main resource in strengthening the biological condition and fertility of the soil is closely related to the life of saprophytic microorganisms. In this place, microorganisms and microbiological processes in the soil have performed an important task. In particular, it has the characteristic of enriching the soil with biological nitrogen due to the normalization of organic matter in the soil, assimilation of free nitrogen in the air by nitrogen-receiving microorganisms. In the article, it was observed that the amount of microorganisms in the composition of typical irrigated gray and meadow soils changes according to the seasons. It was explained that the highest amount of microorganisms was determined in the spring season, it decreased in the summer season, in autumn, the soil temperature and air temperature increased the amount of microorganisms, and in this season, if the activity of microorganisms is observed in the 0-30 cm layer of the soil, it was observed that it decreases towards the lower layers.
Effect of irrigation regimes on the fertility of soybean and sunflower cultivars planted in repeated periods
Authors: Eshonkulov J , Kamilov B
Published: March 2023

The increase in the world’s population means that the demand for food, including vegetable oil and protein products, is increasing day by day. Biometric measurements of the plant, laboratory analysis of soil and plant samples were done using phenological observations “Methods of conducting field experiments”, the amount of protein in soy grains was analyzed based on “Methods for determining the amount of protein in grain and its content”. The results showed that the amount of oil was 58.6% during irrigation according to the pre-irrigation soil moisture content of 65–65–60% relative to the limited field moisture capacity of the 0-50 cm soil layer during irrigation. Furthermore, it was found that when the soil moisture before irrigation was 75-75-65% according to LFMC in the calculation layer of the soil in the 0-50 cm layer in the 1-2-1 system, 1682 m3/ha water was used in soybeans, and it was 2331 m3/ha of sunflower plants.
Obtaining paper products from cellulose-containing plants and researching its field of application
Authors: Egamberdiev E , Akmalova G , Rahmonberdiev G
Published: March 2023

In the world a number of researches are intensively being conducted on the preparation of new paper compositions based on natural polymers, expanding the application scope of products with unique and rare properties using not only plant fibers but also non-traditional fibers, the development of traditional papers for priority areas in this field and manufacturing paper products from mineral fibers with the help of existing devices. Systematic, regular studies of the use of inorganic binders in the preparation of sheet (sheet) materials based on mineral fibers have not yet been carried out by the method of paper technology. Paper products were obtained from cellulose-containing plants. Several quality indicators of paper products were studied. These are: Tearing length, tearing resistance, bending resistance, number of bendings in both directions.