State Conditions Research Articles

Analysis and calculation of electromagnetic force of stator winding and damping bar during dynamic loading of pumped storage generator/motor

AbstractFrequently and rapidly dynamic conversion is one of the main differences between pumped‐storage motor and general hydro‐generator. In the process of changing operating conditions, in order to achieve fast dynamic conversion, the loading rate requirement of pumped storage motors is often much higher than that of conventional generators, which brings great impact on the key structural components of generators, it affects the safe operating life of motors directly. To solve the impact of dynamic loading rate on key structural components of pumped storage motors, for a pumped storage motor as an example, investigating different loading rates during the dynamic conversion of two main operating conditions on pumped storage motors (power generation and electric power) of pumped storage motors are investigated. Calculating accurately the distribution laws of electromagnetic forces of key structural components which contains stator tooth walls and damping strips during dynamic loading. The results show that the different loading rates will affect the force distribution of the key position directly, under the condition of generator state and motor state, the distribution of force on stator winding and damping bar present different laws, it will provide reference for the determination of multi‐state conversion loading rate of pumped storage motor and the improvement of pumped storage motor structure scheme.

THE PUBLIC ADMINISTRATION OF INFORMATION TECHNOLOGIES IN HEALTH CARE FIELD UNDER THE CONDITIONS OF MARTIAL STATE

In the conditions of martial state, the need for fast and accurate processing of large volumes of information, especially in the field of health care, is increasing. This is due to a lack of resources, an increase in the number of victims of military operations, displaced persons, the complication of access to medical services in connection with hostilities, the loss of individual specialists and information arrays, as well as increased risks for information security and the entire process of public management of information technologies in the health care field. The public administration of information technologies in health care is becoming critical to ensure the stability of healthcare services, support communications between healthcare facilities and government agencies, and effectively process and protect healthcare data. The analysis of scientific works on the issue of the public administration of information technologies in health care under the conditions of martial state is insufficiently researched. The article highlights the main challenges of the industry related to the war: ensuring the continuity of medical services, the appropriateness of public administration decision-making in conditions of limited access to open information, problems with logistics, and stable power supply, information protection and cyber security, shortage of qualified personnel; adopted management decisions, and information technology tools, which were used by authorities at the state and regional levels to respond to new challenges, were investigated. In the article, we are offered some recommendations for the further development and management of information technologies in the healthcare field. The main ones are further measures to strengthen cybersecurity, namely the widespread implementation of the Digital Competency Framework for Healthcare Workers in various areas, the implementation of modern information protection systems, the implementation of an information security policy, measures to legalize and update software, deepening the integration of mHealth into the existing eHealth system to enable rapid and remote collection of medical information and the introduction of artificial intelligence elements into healthcare management processes.

Managing singular kernels and logarithmic corrections in the staggered six-vertex model

In this paper, we investigate the spectral properties of the staggered six-vertex model with Z2 symmetry for arbitrary system sizes L using non-linear integral equations (NLIEs). Our study is motivated by two key questions: what is the accuracy of results based on the ODE/IQFT correspondence in the asymptotic regime of large system sizes, and what is the optimal approach based on NLIE for analyzing the staggered six-vertex model?We demonstrate that the quantization conditions for low-lying primary and descendant states, derived from the ODE/IQFT approach in the scaling limit, are impressively accurate even for relatively small system sizes. Specifically, in the anisotropy parameter range π/4 < γ < π/2, the difference between NLIE and ODE/IQFT results for energy and quasi-momentum eigenvalues is of order OL−2.Furthermore, we present a unifying framework for NLIEs, distinguishing between versions with singular and regular kernels. We provide a compact derivation of NLIE with a singular kernel, followed by an equivalent set with a regular kernel. We address the stability issues in numerical treatments and offer solutions to achieve high-accuracy results, validating our approach for system sizes ranging from L = 2 to L = 1024.Our findings not only validate the ODE/IQFT approach for finite system sizes but also enhance the understanding of NLIEs in the context of the staggered six-vertex model. We hope the insights gained from this study have significant implications for resolving the spectral problem of other lattice systems with emergent non-compact degrees of freedom and provide a foundation for future research in this domain.

Numerical study of specific C-shaped heat exchanger using porous medium and coarse mesh coupling method

Porous medium method is an effective simplified approach for the heat exchanger simulation when the numerous tubes and complex structures bring unacceptable computational resources to full-scale simulation. However, for the specific C-shaped heat exchanger, the tube side resistance and flow distribution characteristics that significantly affects the heat transfer and natural circulation performance cannot be obtained by the traditional porous medium method coupled with the one-dimensional node model for tube side. It is urgent to develop a new coupling method that can not only simplify modeling and calculation, but also obtain tube side high-resolution flow heat transfer characteristics. This study presents a novel calculation method which couples the porous medium mesh and the tube side coarse mesh. The coupling method was then applied to a typical C-shaped passive residual heat removal heat exchanger (PRHR HX), which is significant to the stable operation and the mitigation of accident conditions in the nuclear power plant. The coupling calculation method was validated against the full-scaled simulation and data from scaled-down experiment. The average relative error of heat transfer power is 2.1 % under steady state conditions. Under transient conditions, the average absolute error of the fluid temperature and wall temperature are less than 6 K. Then the 3D thermal-hydraulic characteristics of PRHR HX was studied. Owing to a greater gravitational pressure head, the mass flow rates in the extended tubes surpass those in the shorter tubes by a relative deviation of 27.4 %. The upper horizontal tube's heat exchange capacity constitutes approximately 70 % of the total power, leading to enhanced natural circulation. The outlet temperatures from various tubes tend to equalize. The boiling area gradually extended down along the heat transfer tubes. Our work would present an innovative calculation method to the numerical study and design optimization of the C-shaped heat exchanger.

Numerical analysis of heat transfer in annulus composite material at different operation conditions

In this article natural air convection in an inclined annular cage in three dimensions is investigated numerically. This study will examine the impact of the radius ratio of an annulus on heat transfer employing two distinct methods to optimizing effective thermal conductivity: minimizing and maximizing. The annulus is built of graphite/epoxy laminated composite material. There are 12 fins attached to the inner cylinder of the two concentric cylinders that make up the annulus enclosure, which is filled with porous medium. Regarding the annulus's inclination angle “δ”, two scenarios—a horizontal annulus and a vertical annulus—are considered. Constant walls temperature boundary condition and steady state conditions apply to the system with 0.2, 0.3, 0.4 and 0.5 different radius ratio, inclination angle (0o and 90o), and modified Rayleigh number “Ra*” ranged from 10 to 500, The Nusselt number decreased for all parameters as the radius ratio Rr decreased, indicating a wider cold outer cylinder gap. For large values of modified Rayleigh number, the average Nu number ”Nuavg.” decreases with an increase in δ, and increases with a rise in the modified Rayleigh number; for low values of Ra*, δ has no effect. For horizontal, and vertical states “δ=0 o, and 90o respectively, at higher and lower thermal conductivity, the divergence of the average Nusselt is 5.1% and 10%, respectively. In horizontal cylinder adding fins on the inner cylinder is more substantial for due to its impeding effect, and NuL increases with cylinder length. For the outer cold cylinder, a link between Ra* and δ and the average Nusselt number has been established.

Optimal parameter identification of adaptive fuzzy logic MPPT based-bald eagle search optimization algorithm to boost the performance of PEM fuel cell

The output power of proton exchange membrane (PEM) fuel cell is dependent on operating temperature and the membrane water content. Changing the operation condition changes the location maximum power point (MPP) on the nonlinear curve of power versus the current. Therefore, a robust MPP tracking strategy is obligatory to grantee the work of PEM fuel cell around or close the MPP and boost the harvested energy. The suggested tracker is based on the bald eagle search (BES) optimization algorithm to identify the best values to entirely advantage the inherent flexibility of fuzzy logic control (FLC) system furthermore to accomplish rapid and precise tracking. Throughout the optimization procedure, the gains of membership functions of FLC are assigned to be decision variables, while the integral of error is the objective function. To approve the advantage of BES, a comparison with gradient-based optimizer (GBO), osprey optimization algorithm (OOA), particle swarm optimization (PSO), pelican optimization algorithm (POA), blue monkey algorithm (BMA) and henry gas solubility optimization (HGS) is performed. The BES has the highest performance compared with other optimizers; it achieves the best value of 1.7638 flowed by GBO (1.7667) whereas the worst value of 1.7987 is obtained by POA. Additionally, the lowest STD of 0.0046 is achieved by BES followed by GBO (0.0078) whereas the worst value of STD of 0.0243 is obtained by HGS. Finally, the optimized FLC-MPPT-based BES is compared with commonly MPPTs including classical FLC and perturb & observe in terms of dynamic and steady state conditions. The comparison demonstrated that the suggested FLC-MPPT-based BES has fast tracking speed and diminishes the oscillations around MPP in steady state.

The effect of mobile phone electromagnetic fields on the human resting state wake EEG and event-related potential: A systematic review and meta-analysis.

The rapid growth of mobile phone usage and its use of radiofrequency electromagnetic fields (RF-EMF) have raised concerns about potential health risks. Researchers have conducted studies to examine the effects of RF-EMF on the brain using electroencephalography (EEG). We conducted a systematic quality assessment and meta-analysis of published research in this field to establish high-quality studies as references for future protocols. The electronic search yielded 244 records from which a total of 51 studies were included in the review after excluding studies based on study design, and data or report availability. Of these 51 studies, 31 (61%) focused on resting state wake EEG and 20 (39%) on event-related potentials (ERP). None of the 51 studies were free from risk of bias. From the 51 included studies, we were able to use seven studies to create three different groups for meta-analysis for resting state wake EEG and five studies to create 10 different groups for meta-analysis for ERP. Per group the number of studies varies from 1 to 5. Our procedure is the first systematic quality assessment in this field and revealed three important findings. First, there is evidence of an effect on the EEG of a 2G protocol using an eyes-open condition. Second, we did not find evidence for EEG effects during task performance. This suggests that the impact of EMF during task performance is less pronounced compared to the resting state condition. Third, this meta-analysis shows that the field is unable to create an evidence base for most comparisons due to heterogeneity. We therefore advise that all future studies are double-blind in nature, adhere to the methodological standard of randomized experiments, and publish their protocols first.

Validation process against late phase conditions of the passive autocatalytic recombiner simulation code PARUPM as a standalone tool using experimental data from REKO-3 and THAI facilities

In case of a nuclear accident with core damage in a light water reactor, the oxidation of the fuel cladding and other materials could lead to the release of combustible gases (H2 and CO) to the containment building. To mitigate the potential risk of combustion of these gases, passive autocatalytic recombiners (PARs) have been installed in numerous nuclear reactors in Europe and worldwide. PARs recombine H2 and CO with O2 producing H2O and CO2, respectively, without an open flame.PARUPM is a code that simulates the behaviour of PARs using a physicochemical model approach. In the framework of the AMHYCO project (EU-funded Horizon 2020 project), which seeks to advance the understanding and simulation capabilities to support the combustion risk management in severe accidents, the code has been extensively enhanced and developed to simulate PAR operation with H2/CO/O2/steam mixtures. Alongside these new capabilities, the code needed a new validation process.In this paper, the process of validation of PARUPM as a standalone code is described. The validation for steady state conditions was achieved through comparison with REKO-3 experimental data while the transient conditions were compared with results obtained with the THAI test facility. A thorough analysis of the code capabilities was performed by comparing the numerical results with experimental data for a broad series of conditions, namely: a range of different input gas temperatures and concentrations, oxygen starvation, CO poisoning, etc.

Intermittency of gravity wave turbulence on the surface of an infinitely deep fluid: directional effects

This study investigates the influence of surface wave characteristics, specifically wave steepness and directional spreading, on intermittency in deep-water gravity wave turbulence through long-term numerical simulations of three-dimensional potential fully nonlinear periodic gravity waves. We conducted this investigation by estimating the scaling exponent of the surface elevation under different sea state conditions. With our numerical methods, we were able to evaluate the scaling exponents of the structure-function up to 12th order. The observed increased intermittency in directionally narrower sea states and in higher steepness conditions aligns with known effects of quasi-resonant wave–wave interactions and wave breaking. Comparative analyses reveal that both the conventional She–Leveque model and the multifractal models, also used to represent intermittency in wave turbulence of a different nature, exhibit a strong correlation in this study. This observation underscores the universality of intermittency phenomena within wave turbulence.

Effect of Bubbler Irrigation Interval on Yield and Water Productivity of Date Palm cv. Barhee under Khartoum State Conditions, Sudan

Effect of Bubbler Irrigation Interval on Yield and Water Productivity of Date Palm cv. Barhee under Khartoum State Conditions, Sudan

Research on Damage Detection of Dual-Rotor Synchronous Excitation Mine Screen Beams Based on Strain Mode Difference Vibration Mode Analysis.

The frame beam structure of the mine screen, subjected to various excitations, is a critical component of mining machinery. Its stress is intricate, the operational environment is severe, and damage can lead to catastrophic failures resulting in machinery destruction and fatalities. Based on the characterization of the vibration response of mine screen frame beams with varying degrees of damage at the same location and with the same degree of damage but at different locations, this paper develops a method of strain modal difference vibration pattern analysis and damage feature extraction for the detection of structural damage in beams. This method is based on the sensitivity of the sudden change in vibration strain modal difference to small deformations. This method solves the problem of using the conventional structural finite element analysis or experimental modal analysis methods to obtain the displacement mode, intrinsic frequency, and other characteristics, which make it difficult to effectively identify the actual engineering, with the damage conditions of the damage state and damage location of the mine screen frame beam problems. The feasibility and validity of the engineering application of the concept are demonstrated through instances.

Evaluating the continued significance of dam-induced vigorous downstream channel erosion in the context of projected climate change: a case study from Peninsular India

ABSTRACT Although erosion has naturally been driven by rainfall patterns, human activities have increasingly influenced erosion rates in recent times. However, as climate change alters precipitation, future erosion control may once again depend primarily on climate. The primary goal of this investigation was to ascertain whether the issue of escalated erosion, typically linked to downstream dam effects, could diminish in significance due to projected climatic shifts later in this century. An erosion potential index (Ep), formulated as the ratio of the mass of sediment influx from upstream to the frequency of the sediment-carrying flow events, was computed on a tributary of the Godavari River, located downstream of a dam. Using the Soil & Water Assessment Tool (SWAT), virtual experiments were conducted to distinguish the impacts of the dam from projected climate changes on river geomorphology. Two control scenarios were created using the current climate data and simulated regulated and unregulated states of the basin. Employing climate projections and various mitigation scenarios (SSPs) for the 2060s and 2090s, this study estimated Ep values exclusively under future climatic conditions in an unregulated state of the basin. Results indicate that, in the unregulated state without the existence of the upstream dam, future climate impacts on erosion outweigh the current effects of the dam, underscoring the growing influence of climate on geomorphology. It suggests that existing structural interventions may lose their geomorphic significance in the face of future climate conditions.

Current challenges and threats to the implementation of social policy under the conditions of marital state

The problems of the implementation of social policy are currently determined by the accumulated problem of the unreformed sector of the social sphere and the extremely negative impact of the martial law, which leads to an increase in the critical mass of people who need social assistance and effective solutions that can contribute to the implementation of social policy in accordance with current challenges and threats. This article focuses on identifying and structuring current challenges and threats to the implementation of social policy under martial law. It is established that, given the longterm nature of martial law, social policy is currently under the critical influence of pre2022 problems, which are exacerbated by a large-scale invasion, and the structuring of current challenges and threats that are characteristic of the current state of social policy implementation, given martial law, is an important and relevant topic for research. After all, today the issue of clearly fixing and structuring the current challenges and threats to the implementation of social policy in the conditions of martial law is acute. The purpose of the article is to define and structure the current challenges and threats to the implementation of the social sphere in the conditions of martial law. In the process of research, it was established that in today’s conditions, the implementation of social policy has significant limitations and barriers. Four groups of institutional restrictions are identified, which include the inconsistency of the legal framework; bureaucratic obstacles; insufficient coordination between various state authorities; low level of professional training of social workers. Three groups of obstacles to the effective implementation of social policy are also highlighted, namely: economic, political, and corruption. The main types of threats are identified, including: financial, social, technical and security, each of which creates a whole range of challenges. The following challenges have a high priority to be taken into account in the implementation of social policy: the problem of the state budget deficit, dependence on international donors, the increase in the number of people who need social protection, the decrease in the standard of living and the provision of housing, the further course of military operations and their intensity, internal instability. It was established that further research should be focused on finding effective tools that will allow, taking into account the existing risks and threats, to develop appropriate mechanisms for minimizing the identified threats and challenges for the effective implementation of social policy as quickly as possible.

Modeling, optimization and operability analysis of Lurgi and Haldor Topsøe methanol synthesis reactors

Abstract In this research is focused on modeling, simulation and operability analysis of methanol synthesis reactors in the Lurgi and Haldor Topsøe methanol plants at steady state condition. In this regard, the tubular methanol synthesis reactors are mathematically modeled based on the laws of conservation of mass and energy considering interparticle resistance inside the commercial CuO–ZnO/Al2O3 catalyst. Then, the methanol productivity, carbon conversion, and thermal performance of both configurations are compared at the same weight hourly space velocity. The mole fraction of methanol in the outlet stream from Lurgi and Topsøe designed reactors are 9.08 and 9.71, respectively. In addition, the hotspot temperature in the Lurgi and Topsøe reactors are 278.8 and 267.7 °C based on the considered model, respectively. The carbon dioxide and carbon monoxide conversion in the Topsøe designed reactor are 8.95 and 4.89 % higher compared to the Lurgi reactor. Finally, a multi-objective optimization problem is programmed considering methanol production rate, carbon dioxide conversion and catalyst loading as objective functions and the optimal operating conditions and specifications of Topsøe reactor are obtained considering two different strategies. The simulation results show that applying the optimal conditions on the Topsøe designed reactor enhance the methanol productivity up to 16.04 %.

Gas Pipeline Leak Detection by Integrating Dynamic Modeling and Machine Learning Under the Transient State

This study focused on developing machine learning models to detect leak size and location in transient state conditions. The model was designed for an onshore methane–hydrogen blending gas pipeline in Canada. Base case simulations revealed significant effects on mass flow and pressure due to leaks, with the system taking approximately 6 h to reach a steady state from transient conditions. This made it essential to analyze the flow characteristics during the transient state. Trend data from the pipeline’s inlet and outlet were examined, considering the leak size and location. To better represent the data over time, a method was used to create two-dimensional images, which were then fed into a CNN (convolutional neural network) for training. The model’s accuracy was assessed using classification accuracy and a confusion matrix. By refining the data acquisition process and implementing targeted screening procedures, the model’s classification accuracy increased to over 80%. In conclusion, this study demonstrates that machine learning can enable rapid and accurate leak detection in transient state conditions. The findings are expected to complement existing leak detection methods and support operators in making faster, more informed decisions.

Intestinal epithelial Gasdermin C is induced by IL-4R/STAT6 signaling but is dispensable for gut immune homeostasis

Gasdermin C is one of the least studied members of the gasdermin family of proteins, known for their critical involvement in pyroptosis and host defense. Furthermore, evidence for the role of Gasdermin C in the intestine is scarce and partly controversial. Here, we tested the functional role of Gasdermin C in intestinal homeostasis, inflammation and tumorigenesis. : We studied Gasdermin C in response to cytokines in intestinal organoids. We evaluated epithelial differentiation, cell death and immune infiltration under steady state conditions in a new mouse line deficient in Gasdermin C. The role of Gasdermin C was analyzed in acute colitis, infection and colitis-associated cancer. Gasdemin C is highly expressed in the intestinal epithelium and strongly induced by the type 2 cytokines IL-4 and IL-13 in a STAT6-dependent manner. Gasdermin C-deficient mice show no changes in tissue architecture and epithelial homeostasis. Epithelial organoids deficient in Gasdermin C develop normally and show no alterations in proliferation or cell death. No changes were found in models of acute colitis, type 2 intestinal infection and colitis-associated cancer. Gasdermin C genes are upregulated by type 2 immunity, yet appear dispensable for the development of intestinal inflammation, infection and colitis-associated cancer.

О развитии авторского права на фотографические произведения в доцифровую эпоху: советский период

The problems of the formation and development of copyright for photographic works in the Soviet period (1917–1991) are considered. The historical analysis is based on the stages of codification of Soviet civil and copyright legislation in the 20s, 60s and 90s. Along with the general trends of copyright, its specific practice and theory in the conditions of the Soviet state are investigated. On the example of the legal protection of photographic works, on the one hand, the formation and deformation of exclusive rights, the provisions of which were taken from pre-revolutionary legislation, are shown. On the other hand, the transition to the codification of civil and copyright law in 1991 is presented not only taking into account the perestroika processes in the USSR, but also in connection with the advent of a new information technology era of computers and the Internet.

Development of a Power Conversion System for a Wave Energy Converter connected to the Electrical Network

Abstract Global efforts are focused on promoting a sustainable energy supply by increasing the use of renewable energies and decreasing reliance on conventional sources. Among renewable sources, Wave energy is a promising one, but it is still widely untapped worldwide. In the current energy context, it is crucial to synchronize the characteristics of renewable sources with the needs of the existing electrical network which is undergoing a deep change towards the smart grid paradigm. Power electronic converters, as interface devices, play a fundamental role in facilitating the transfer of renewable energy to the electrical network. For this reason, this study focuses on the design and optimization of an electrical power conversion system for a wave energy converter (WEC) coupled with a hydraulic power take-off. This electrical power conversion system allows the WEC to connect to the electrical network and deliver a smooth output electrical power. Indeed, thanks to a particular control system, the conversion from mechanical power to electrical power is achieved with losses of less than 5% in regular sea state conditions

Cold solar: PVT heat exchanger designs for heat pump integration

There has been an increase in solar photovoltaic/thermal (PVT) research in recent years, however, relatively little research has been dedicated to the design of PVT collectors as part of a heat pump system. This study aims to identify cost-effective design strategies for a PVT collector absorber to be integrated into a ground source heat pump (GSHP) circuit and enhance heat capture from the ambient air. The effect of geometry, material selection, fins, and forced convection on the overall U-value and thermal performance coefficients of the collector, are evaluated under steady state conditions using numerical modelling tool COMSOL Multiphysics. An annual mean fluid temperature profile is derived from a PVT + GSHP system simulation to calculate the annual thermal energy output, energy-to-mass and energy-to-cost ratios of the absorbers. Results show that the addition of fins and forced convection have the greatest influence on collector thermal performance, while material selection has a negligible impact. The corrugated, polycarbonate absorber with 10 mm fins, generates 55 % more thermal energy (1,464kWhth/m2-yr) than the reference metallic sheet and tube collector at an energy-to-cost ratio 1/10th the reference, suggesting good market potential. An exergy analysis reveals that thermal exergy contributes 20 % to 50 % of the total exergy output, highlighting that low-temperature PVT designs exhibiting a smaller thermal share relative to electrical exergy compared to their higher temperature counterparts. This work’s novelty and contribution comes from PVT design specifically for GSHP integration, examined at component and system levels, from both technical and economic perspectives.

A Novel Sea State Classification Scheme of the Global CFOSAT Wind and Wave Observations

AbstractOcean waves are essential elements across the air‐sea interface, regulating momentum and energy transfer. The mixture of wind sea and ocean swell coupled with surface winds results in diverse sea state conditions that modify the local air‐sea interaction. Previous classifications of wind waves and swells are mostly binary that are insufficient to represent the complexity of sea states. In this study, we utilize wind and wave measurements from the China‐France Oceanography Satellite (CFOSAT) to construct an observational wind‐wave ensemble. Four key parameters: wind speed, significant wave height, inverse wave age, and spectral width are selected out of six variables based on their correlations. Employing the unsupervised learning of k‐means clustering, global sea states are categorized into six distinct classes. These classes, characterized by unique centroids and separated in the feature space, represent specific wind regimes and degrees of wave development. Global occurrence highlights that each sea state is region‐specific, bridging the spatial gap of swell and wind sea dominated areas, respectively. This new grouping scheme complements the traditional wind sea and/or swell classification by resolving the diversity of wave regimes. The six‐class classification enables us to identify transitional states and hybrid conditions that may have been overlooked in the binary classification scheme, which shall help investigate the impact of ocean waves on the air‐sea interaction under varying sea states.