Occurrence Of Phenomenon Research Articles

The dance of neurons: Exploring nonlinear dynamics in brain networks

The brain is a complex, nonlinear system, exhibiting ever-evolving patterns of activities, whether in the presence or absence of external stimuli or task demands. Nonlinearity can notably obscure the link between structural constraints enforced on the interaction and its dynamical consequences. Suitable nonlinear dynamical models and their analysis serve as essential tools not only for bridging structural and functional understanding of the brain but also for predictably altering the complex dynamical organization of the brain. Here, starting from a large-scale network of threshold Hodgkin–Huxley style neurons, we formulate the average nonlinear dynamics implicitly following from the Wilson–Cowan assumptions. We investigate the influence of biophysical and structural properties on the complexity of neural dynamics at the microscale level and its relationship with the macroscopic Wilson–Cowan model. Incorporating the elements in the model can help identify more realistic regimes of activity and connect the mathematical prediction of increasing nonlinearity to physical manipulations. Our simulations of the temporal profiles reveal dependency on the binary state of interacting subpopulations and the random property of structural network at the transition points, when different synaptic weights are considered. For substantial configurations of stimulus intensity, our model provides further estimates of the neural population’s dynamics, ranging from simple-periodic to aperiodic patterns and phase transition regimes. This reflects the potential contribution of the microscopic nonlinear scheme to the mean-field approximation in studying the collective behaviour of individual neurons with particularly concentrating on the occurrence of critical phenomena. We show that finite-size effects kick the system in a state of irregular modes to evolve differently from predictions of the original Wilson–Cowan reference. Additionally, we report that the complexity and temporal diversity of neural dynamics, especially in terms of limit cycle trajectory, and synchronization can be induced by either small heterogeneity in the degree of various types of local excitatory connectivity or considerable diversity in the external drive to the excitatory pool.

On the global existence of solutions to a chemotaxis system with signal-dependent motility, indirect signal production and generalized logistic source

This paper is devoted to a chemotaxis system with signal-dependent motility under homogeneous Neumann boundary conditions in a bounded domain. We prove that this problem possesses a global classical solution which is uniformly bounded under weaker conditions than that obtained by Lv and Wang (2020). The findings of our study demonstrate the presence of a consistent decay rate, effectively ruling out the occurrence of blow-up phenomena in the system across all spatial dimensions.

The contest between artificial management and natural environment determines the adaptive strategies of leaf morphogenesis in Sabina chinensis.

Sabina chinensis is a typically heteromorphic leaf evergreen tree worldwide with both ornamental and ecological value. However, the shaping mechanism of heteromorphic leaves of S. chinensis and its adaptability to environment are important factors determining its morphology. The morphological change of S. chinensis under different habitats (tree around) and treatments (light, pruning and nutrients) was investigated. Our findings suggested that the prickle leaves proportion was associated with low light intensity and soil nutrient scarcity. Stems and leaves are pruned together to form clusters of large prickle leaves, while only pruning leaves often form alternately growing small prickle leaves and scale leaves, and the length of the prickle leaves is between 0.5 cm and 1 cm. The gene expression of prickle leaves is higher than that of scale leaves under adverse environmental conditions, and the gene expression correlations between small prickle leaf and scale leaf were the highest. Homologous and heterologous mutants of gene structure in prickle leaves were larger than those in scale leaves. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway showed that phenylpropanone and flavonoid biosynthesis were common enrichment pathways, and that the enrichment genes were mainly related to metabolism, genetic information processing and organismal systems. Therefore, we concluded that the occurrence of the heteromorphic leaf phenomenon was related to the changes in photosynthesis, mechanical damage and nutrient supplementation. The organic matter in the S. chinensis prickle leaves was reduced under environmental stresses, and it will be allocated to the expression of prickle leaf or protective cuticles formation.

Impact of media information and reinfection in a COVID-19 dynamical model: emergence of periodic orbits through Hopf bifurcation

In the current study, we investigate an SIRI compartmental model of COVID-19 incorporating the effect of social media and TV advertisements on the disease transmission of COVID-19 in the presence of reinfection. We have performed basic analysis on the model and studied the basic reproduction number R0 . The proposed model admits two disease-free equilibria and upto four endemic equilibria under certain parametric restrictions. We have performed local stability analyses via the Routh-Hurwitz criterion. Global asymptotic stability is established for the unique endemic equilibrium, when it exists, via the geometric approach. We have also scrutinized the proposed model for occurrence of the bifurcation phenomena and found that both forward and backward bifurcation transpires for a certain set of parameters. Simultaneously, the proposed model also displays saddle-node bifurcation. When R0>1 , the possibility of numerous endemic equilibria exists. These numerous equilibria exhibit oscillations through Hopf bifurcation leading to rich and complicated dynamics. The model is found to show hysteresis. Effect of levels of media and reinfection on the infected compartment is demonstrated and sensitivity analysis of influential model parameters is carried out. Data fitting is carried out to validate the proposed model by comparison of real data in India and the proposed model. Lastly, numerical simulations are executed for several examples to provide analytical and epidemiological understanding into model behaviour.

Cultural landscapes in climate change: A framework for resilience in developing countries

Cultural landscapes, particularly cities with rich historical and cultural heritage, play a crucial role in bolstering the resilience of local communities. The occurrence of climate change-induced phenomena jeopardizes cultural landscapes, resulting in the deterioration of historical structures, natural landscapes, cultural heritage, the economy, and the livelihoods of residents in these areas. Therefore, adopting a resilient approach is essential for the integrated management of cultural landscapes. This study develops a model for enhancing cultural landscape resilience to climate change in Nishapur, a historical and cultural city in Iran. Through desk studies, factors affecting the resilience of cultural landscapes to climate change were extracted in the context of developing countries. Subsequently, a model was developed based on the frequency of the occurrence of dimensions and indicators. Snowball sampling was used to distribute questionnaires to 310 members of the academic and professional communities in the field. Next, confirmatory factor analysis (CFA) was conducted using IBM SEM-AMOS to analyze the data and measure the reliability and validity of the model. The findings indicate that the driving factors of change, such as changes in livelihood and social issues, historical fabric and physical environment, natural hazards, biodiversity patterns, and management patterns, can significantly affect the resilience of cultural landscapes to climate change. The developed model can contribute to policymaking in various fields, including urban design and planning, economics, sociology, and cultural heritage conservation. This can play a vital role in creating cultural landscapes that are resilient to the increasing impacts of climate change.

Study of methods for predicting the stability of preparatory workings in the mines of Western Donbas

Purpose. Analysis of the effectiveness and feasibility of existing methods for predicting preparatory workings. Research methodology. The research was conducted using an analytical method (analysis, explanation, synthesis, comparison) and statistical data processing method. Research results. The conducted research allowed determining that the coal-bearing sedimentary massif of the Western Donbas, as a result of complex tectonic movements, is characterized by developed and intensive tectonic disturbances of a ruptural and plicative nature. The appearance of plicative disturbances in the hanging wall of the coal seam, accompanied by an increase in their thickness, leads to the concentration of stresses in the areas of disturbances caused by approaching the mining face. Regional plicative disturbances cause the formation of zones of anomalous activity in the intact mining massif. In addition to gravitational forces affecting the geological structure, tectonic stresses directed along the bedding plane are added to this phenomenon. Tectonic stresses are oriented in the direction of the main curvatures of the natural surface of rock deposition and depend on their magnitude. Geological deviations of various types are key indicators of anomalies in the tectonic environment and zones of reduced strength in an intact mining massif. These anomalies can result from the complex interaction of geological processes, including tectonic activity, water flow activity, and other natural factors. These deviations become fundamental factors contributing to the occurrence of gas-dynamic phenomena and rockfalls during the preparatory mining stage. Scientific novelty. The regularity of the interaction of geomechanical parameters of elements of the "layered massif – excavation support" system has been established. Practical significance. Studying methods for predicting the stability of preparatory workings allows for the development of effective excavation support systems according to geological conditions and prevents possible accidents and rockfalls in mining working areas.

Cold Water Phenomenon in Autumn in the Sea Area of the Xisha Islands

AbstractUsing satellite observation and reanalysis data, we studied the cold water phenomenon in the sea area of the Xisha Islands in autumn from 2003 to 2022. The cold water phenomenon refers to a colder water body relative to its surrounding area, which can partially offset the impact of global warming, thereby contributing to the protection and restoration of marine ecosystems. The cold water with a central position close to the Xisha Islands is distributed in a nearly circular area, and exhibits seasonal and interannual variations. It usually occurs at the end of September, with its intensity rapidly increasing and reaching its peak on October 1, then gradually weakening, and finally disappearing by November 6. The maximum intensity of the cold water phenomenon can reach 1.6°C. This phenomenon notably observed in October 2006, 2009, 2013 and 2022, with intensities reaching 0.9°C, 1.1°C, 1.1°C, and 0.4°C, respectively. The dynamic mechanism of its formation can be described as follows: in autumn of some years, the northeast monsoon occurs in the northern part of the South China Sea (SCS), while the southwest monsoon still prevails in the southern part of the SCS, which causes the generation of strong positive wind stress curl (WSC) near the Xisha sea area. The positive WSC causes cyclonic circulation and further causes upwelling through Ekman pumping, which transports low‐temperature water from the seabed to the sea surface and thus leads to the occurrence of the cold water phenomenon in the Xisha sea area.

Application of Guidezilla Extension Catheter in Thrombus Aspiration During Percutaneous Coronary Intervention

Acute myocardial infarction (AMI) poses a significant threat to human health and safety, representing a coronary heart disease that can affect human life. Percutaneous coronary intervention (PCI) is considered the optimal method for saving the lives of AMI patients and optimizing treatment outcomes in emergency settings. However, over the years of research and clinical data, it has been observed that PCI also has certain limitations, such as the occurrence of a no-reflow phenomenon or the re-occlusion of small arteries in the distal myocardium by small thrombi. Therefore, based on recent research, this article aims to elaborate on the effectiveness and safety of the Guidezilla extension catheter in thrombus aspiration during percutaneous coronary intervention, while comparing it with traditional aspiration catheters. The objective is to provide clinicians with new treatment options and improve patient outcomes.

CONCEPTUAL FRAMEWORK FOR FORMING AN ENTERPRISE ANTI-CRISIS MANAGEMENT SYSTEM

The main reason for the crisis in domestic enterprises is the low level of stimulation for further development. Other reasons that contribute to the crisis include loss of efficiency of production facilities and passivity of counterparties, lack of prospects for stabilizing the economic situation of enterprises. Also among the factors noted is the inconsistency of the mechanism for managing the business processes of the enterprise with the requirements of today, the uncertainty and unpredictability of the economic environment in Ukraine during the war and post-war period leads to destabilization of the business activity of enterprises. Impact of the war on the majority of economic entities in Ukraine is a difficult test for the development of the domestic economy. This situation showed the incompetence of business owners in case of failure to fulfill contractual obligations, as well as the provision of unpaid deferments to employees for insignificant periods, reduction or liquidity of general purchases, purchases, etc., destabilization of logistics stability, insignificance of a specific situation. In the conditions of an unstable external environment, it is practically impossible to strategically plan and forecast the company's development scenarios. We are observing a situation where the incomes of enterprises have significantly decreased and expenses have increased. Considering the high probability of occurrence of crisis phenomena in the activities of enterprises, especially in modern conditions, this indicates the necessity of forming a system of anti-crisis management of the enterprise, countering their development and neutralization.

Low-Dose Ionizing γ-Radiation Elicits the Extrusion of Neutrophil Extracellular Traps.

Patients with cancer frequently undergo radiotherapy in their clinical management with unintended irradiation of blood vessels and copiously irrigated organs in which polymorphonuclear leukocytes circulate. Following the observation that such low doses of ionizing radiation are able to induce neutrophils to extrude neutrophil extracellular traps (NET), we have investigated the mechanisms, consequences, and occurrence of such phenomena in patients undergoing radiotherapy. NETosis was analyzed in cultures of neutrophils isolated from healthy donors, patients with cancer, and cancer-bearing mice under confocal microscopy. Cocultures of radiation-induced NETs, immune effector lymphocytes, and tumor cells were used to study the effects of irradiation-induced NETs on immune cytotoxicity. Radiation-induced NETs were intravenously injected to mice for assessing their effects on metastasis. Circulating NETs in irradiated patients with cancer were measured using ELISA methods for detecting MPO-DNA complexes and citrullinated histone 3. Irradiation of neutrophils with very low γ-radiation doses (0.5-1 Gy) elicits NET formation in a manner dependent on oxidative stress, NADPH oxidase activity, and autocrine IL8. Radiation-induced NETs interfere with NK cell and T-cell cytotoxicity. As a consequence, preinjection of irradiation-induced NETs increases the number of successful metastases in mouse tumor models. Increases in circulating NETs were readily detected in two prospective series of patients following the first fraction of their radiotherapy courses. NETosis is induced by low-dose ionizing irradiation in a neutrophil-intrinsic fashion, and radiation-induced NETs are able to interfere with immune-mediated cytotoxicity. Radiation-induced NETs foster metastasis in mouse models and can be detected in the circulation of patients undergoing conventional radiotherapy treatments. See related commentary by Mowery and Luke, p. 3965.

Size Scaling of Condensates in Multicomponent Phase Separation.

Constant proportionalities between cells and their intracellular organelles have been widely observed in various types of cells, known as intracellular size scaling. However, the mechanism underlying the size scaling and its modulation by environmental factors in multicomponent systems remain poorly understood. Here, we study the size scaling of membrane-less condensates using microdroplet-encapsulated minimalistic condensates formed by droplet microfluidics and mean-field theory. We demonstrate that the size scaling of condensates is an inherent characteristic of liquid-liquid phase separation. This concept is supported by experiments showing the occurrence of size scaling phenomena in various condensate systems and a generic lever rule acquired from mean-field theory. Moreover, it is found that the condensate-to-microdroplet scaling ratio can be affected by the solute and salt concentrations, with good agreement between experiments and predictions by theory. Notably, we identify a noise buffering mechanism whereby condensates composed of large macromolecules effectively maintain constant volumes and counteract concentration fluctuations of small molecules. This mechanism is achieved through the dynamic rearrangement of small molecules in and out of membrane-free interfaces. Our work provides crucial insights into understanding mechanistic principles that govern the size of cells and intracellular organelles as well as associated biological functions.

Comparative analysis of the variability and impacts of tropical cyclones in flood-prone areas of Zimbabwe

Tropical cyclones (TCs) are extreme meteorological events that cause significant deaths, infrastructure damage, and financial losses around the world. In recent years, the Eastern Highlands of Zimbabwe's have become increasingly vulnerable to TCs caused by Indian Ocean tropical cyclones making landfall more frequently. There is still a limited understanding of the phenomenon and the quantification of its impacts. The aim of this research is to conduct a comparative analysis of the variability in the severity of tropical cyclones by analysing historical storm tracks and mapping the environmental impacts in Zimbabwe's Chimanimani and Chipinge districts. Results indicate that, between 1945 and 2022, the Eastern Highlands of Zimbabwe experienced 5 of the total 865 cyclones in the Southwest Indian Ocean. The maximum sustained winds from the Cyclone Idai in the Eastern Highlands were recorded as 195 km/h. Some of the remote sensing-based indices used to extract spatial information about the condition of vegetation, wetlands, built-up area, and bar land during pre and post cyclonic events included the Normalized Difference Vegetation Index (NDVI) and Modified Normalized Difference Water Index (MNDWI). Analysis of NDVI in the Eastern Highlands revealed that there was a significant decrease in vegetated area because of the cyclone impact, with a decrease of 2.1% and 16.68% for cyclone Japhet and Idai respectively. The MNDWI shows a 10.74% increase in water content after cyclone Eline. Field validation in 2019 confirms the research findings. An Operations Dashboard Disaster Management System was developed in order to disseminate information to the affected stakeholders about the potential risk that the face due to the occurrence of the natural phenomena.

Use of Realism as Social Commentary on Specific Subject Matter in Painting: An Analysis of the Realist Paintings of Zephania Lukamba, Kenyatta University, Nairobi, Kenya

The creation of any work of art often has a purpose or an intent. In this regard, artists endeavour to create pieces of artwork that bear or propagate certain meanings or points of view and also express some social phenomena that are unique to a particular environment or what has often been referred to as a catchment area. This is usually an important artistic undertaking because artists have the innate responsibility to observe certain social peculiarities and visually record them for all their worth. Some of these peculiarities are a reflection of society and its circumstantial behavioural tendencies often brought about by various factors; such as social-economic malaise and bad governance that precipitates social decay. When an artist embarks on such an artistic depiction of his or her own social environment, then there is a need to give it due artistic attention. This study featured 22 paintings based on the subject matter of the overloading of vehicles. Although the paintings appeared generally alike in terms of layout and execution, it is the depiction of the paradox of the repeated occurrence of the same phenomenon which in reality reflects a tendency that is both widespread and bizarre. In this regard, each painting depicts a scene that in reality is in itself a specific curious occurrence. This, in retrospect, can be seen as a type of popular culture of defiance and of the absurd. Since the overloading of any vehicle is ordinarily not only unwarranted and dangerous, but also blatantly illegal, the artist, in his observations which constituted this study, depicts a societal problem that has degenerated into impunity. This study, therefore, sought to find out how effective such focused paintings were as an avenue for social commentary. The artist over a period of time observed incidents of overloading as they manifested themselves in real-life occurrences and made the necessary sketches that were later developed into paintings in the studio. The paintings were examined using formal analysis to delve into their composition and use of elements and principles as well as descriptive analysis to explore their meaning or what the artist intended to convey. The study posits that the essence of such focused paintings in this study is that they become a visual pointer to the wider debate about the debilitating effect of such social malaise upon the psyche of society. The ordinary citizenry subsequently becomes spectators in their own space that degenerates into such recklessness and disregard for individual and collective safety as well as the rule of law

In-situ consolidation of thermoplastic composites by automated fiber placement: Characterization of defects

The emergence of automated manufacturing of composites has not only transformed the manufacturing of optimized and geometrically complex structures but has also expanded the promising prospect of in-situ manufacturing of thermoplastic composites (TPC), where both material placement and consolidation are carried out by automated fiber placement (AFP) equipment, streamlining the process into single step manufacturing. However, the inherent complexities in different aspects of robotic automation, imperfections in the supplied material, and the occurrence of multi-physical phenomena during in-situ consolidation introduce various manufacturing-induced defects. While the defects in thermoset composites (TSC) made by AFP have been widely studied in the past, this study explores the diverse defects at micro and macro scales for TPCs made by AFP, with a focus on carbon-fiber/poly-ether-ether-ketone (CF/PEEK) tapes consolidated using hot gas torch (HGT) heating system. An overview of defects and associated characteristics is presented across three phases: defects in supplied impregnated tapes, defects and limitations in performance of AFP system, and defects in the final in-situ consolidated composite. For the defects subject to studies in the past, the description is limited to a concise review, while those with limited understanding are supported by new empirical observations in this work.

Observation and all-optical manipulation of replica symmetry breaking dynamics in a multi-Stokes-involved Brillouin random fiber laser photonic system

In this paper, we propose and demonstrate an all-optical control of RSB transition in a multi-wavelength Brillouin random fiber laser (MWBRFL). Multi-order Stokes light components can be subsequently generated by increasing the power of the Erbium-doped fiber amplifier (EDFA) inside the MWBRFL, providing additional disorder as well as multiple Stokes-involved interplay. It essentially allows diversified laser mode landscapes with adjustable average mode lifetime and random mode density of the 1st order Stokes, which benefits the switching between replica symmetry breaking (RSB) and replica symmetry (RS) states in an optically controlled manner. Results show that the average mode lifetime of the 1st order Stokes component gradually decreases from 250.0 ms to 1.2 ms as high orders from the 2nd to the 5th of Stokes components are activated. Meanwhile, the order parameter q of the 1st order Stokes random lasing emission presents distinct statistical distributions within the selective sub-window under various EDFA optical powers. Consequently, all-optical dynamical control of the 1st Stokes random laser mode landscapes with adjustable average mode lifetime turns out to be attainable, facilitating the RSB transition under an appropriate observation time window. These findings open a new avenue for exploring the underlying physical mechanisms behind the occurrence of the RSB phenomenon in photonic complex systems.

Highly active ZnO/Fe3+-TiO2 photocatalysts for visible-light photodegradation application and its colour change behaviour by d-d transition

Highly active novel ZnO/Fe-TiO2 composite catalysts with p-n junction heterostructure have been fabricated by adding commercial ZnO and sol–gel derived Fe-TiO2 nano-powders controlled by grinding and drying. This work reported that doped Fe (III) with TiO2 form a p-type semiconductor and whereas ZnO is an n-type semiconductor. The slight variation of electronegativity between ZnO and TiO2 causes a strong rectifying action for the formation of an interface between ZnO and Fe-TiO2. The occurrence of red shift phenomenon in absorption spectrum of the samples suggest the outcome of d-d transition of Fe3+ (2T2g → 2A2g, 2T1g) and the charge transfer transition between interacting Fe3+ ions (Fe3+ + Fe3+ → Fe4+ + Fe2+). These Fe3+ 3d states in addition to oxygen vacancies and Ti3+ centers create band states, thereby favouring the electronic transition to these levels and resulting in narrowing of TiO2 band gap. A direct confirmation is the increase of Urbach energy with the lowering in the band gap of ZnO/Fe-TiO2.The crystal field splitting of d orbitals (5 degenerate orbitals) of Fe3+ and the approach of free ligand ions which split into two sets and Fe3+ ligand field transition is discussed schematically. The photocatalytic activities of these heterostructure photocatalysts were evaluated by degrading toxic cationic organic dyes such as Methylene Blue (MB) and Malachite Green Oxalate (MG) under visible light. The mechanism of photocatalysis has been recommended which is based on the relative band structure of the semiconductor and integrated heterostructure. The formation of a spike barrier in the CB at the interface gives rise to trap sites that capture the migration of charge carriers and occurs recombination of electron-hole pair at higher Fe(III) doping concentration. The dark adsorption property of the catalysts sample has been also studied.

Mining and geological conditions for the occurrence of sudden gas-dynamic phenomena in the coal mines of the Donets Basin

Over a long period in the development of coal deposits in the Donets Basin, a technogenic multi-level system of workings has been created. The increase in the number and power of gas-dynamic phenomena in coal mines occurred in connection with the increase in the working depth and the expansion of coal workings towards the technical limit of the mine field. The characteristics of the hydrocarbon component in the gas mixture of coal fields are constantly changing, and their content increases significantly in tectonically disturbed zones of coal rock massifs. Qualitative and quantitative parameters of gas mixture indicators are controlled by the tectonic structure of coal rock massifs. While studying the mining and geological conditions in the coal mines of the Donets basin, it has been established that the main factors provoking sudden gas-dynamic phenomena include tectonic discontinuous faults (as well as small-amplitude faults or their zones), abnormally high bed pressures, stress state and gas content of the massif. The results of the conducted research will become the foundation for predicting mining and geological conditions favorable for gas-dynamic phenomena in coal workings, which will make it possible to develop a concept for preventing potential dynamic phenomena in mines.

Study of intermittent jets and free-surface-pressurized flow in large hydropower tailrace tunnel

The tailrace tunnel system, as a core component of hydroelectric power stations, directly influences the stability and efficiency of the power generation process. Transient conditions often lead to the occurrence of complex unsteady flow phenomena in the tailrace tunnel. In this study, numerical methods integrating open channel flow, multiphase flow, and compressible models were combined to conduct hydraulic analysis of the tailrace system in large hydroelectric power stations. Under specific conditions, periodic jet phenomena were observed, corroborating field observations. The research revealed that the proximity of downstream water levels to the crest level of the tailrace outlet is a prerequisite for the periodic jetting phenomenon, with a sudden rise in water level serving as a triggering condition. Although the surge shaft effectively mitigates wave action, it fails to entirely eliminate the influence of pressure pulsations, resulting in a 23.2% increase in pressure pulsation amplitude in the turbine area. However, the efficiency of the turbine unit is hardly affected; only a slight loss of energy occurs due to the increase in local turbulent entropy production, deemed inconsequential for the overall system. This study aims to investigate the complex response of tailrace tunnel systems in hydroelectric power generation amidst abrupt changes in downstream river, providing crucial insights for the engineering design and operation of large-scale power stations.

Spatially averaged global model of HBr/Cl2 inductively coupled plasma discharges

The utilization of HBr/Cl2 mixed gas discharge in semiconductor etching processes has been a subject of analysis both experimentally and through simulations to understand its discharge characteristics. In this study, we have developed a model that extends the previous global model of the HBr/Cl2 plasma. The electron temperature and densities are solved in a self-consistent manner, while previous global model uses the measured electron temperature and electron density. Additionally, we have included further data on electron collision reactions to enhance accuracy. This model was then compared with experimental results obtained from pure HBr, pure Cl2, and HBr/Cl2 plasmas. The calculated results align well with the experimental findings within the margin of error. One notable observation from our study is the occurrence of an unusual phenomenon: as the HBr partial concentration increased, the Br+ ion flux initially increased until the ratio reached 0.5, after which it decreased. This behavior can be attributed to Br+ ions being predominantly produced through collisions between Br atoms and electrons. The dominant mechanisms for Br atom generation involve dissociations by Cl radicals, such as Br2 + Cl → Br + BrCl. Consequently, there exists an optimal flow rate at which the Br+ ion flux is maximized.

Pre-Disaster Optimal Operation Strategy for Hydrogen-Fuel-Based Isolated Power System with Disaster Uncertainties

The increasing occurrence of severe weather phenomena presents substantial difficulties for electricity distribution systems. This study investigates the integration of hydrogen production plants (HPPs) into power distribution networks to bolster resilience against the increasing frequency of extreme weather events. It highlights the innovative use of hydrogen, generated from renewable sources, as an energy storage medium to ensure a stable power supply during disruptions. By employing stochastic optimization, the study aims to effectively manage hydrogen production and utilization, considering uncertainties in disaster scenarios and energy demands. It addresses critical research gaps, such as the lack of focus on pre-disaster preventive scheduling using hydrogen, the under-explored application of stochastic optimization in such contexts, and the predominance of real-time response strategies over pre-emptive measures. This approach significantly advances current understanding by proposing novel strategies that leverage hydrogen production and sophisticated optimization to enhance the resilience of power networks against extreme weather events. In some scenarios, using our method can reduce the cost of pre-disaster prevention by approximately 15.68% while ensuring that the disaster recovery effect remains unchanged.