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The presence of ethanol in the water solution during irradiation by ionizing radiation decreases the number of OH and H radicals. Since the living cell is mainly composed of water, this causes less damage to the DNA molecule irradiated by low-LET ionizing radiation where an indirect effect prevails. Ethanol thus acts as a radioprotective substance, scavenging radicals H and OH. This fact can be used in various practical applications in which living cells are irradiated by ionizing radiation to protect them. We used hybrid Petri nets to simulate all dynamic processes, including chemical reactions and the simultaneous diffusion of radical clusters. The mathematical simulating model enables us to simulate the damage to the DNA molecule by the radical cluster arising at various distances from this molecule. [ABSTRACT FROM AUTHOR]

Objectives: Fluoroscopic guided procedures are a mainstay for interventional radiology (IR) procedures. Practice is needed for the novice to interpret fluoroscopic images and simultaneously perform the procedure hands-on as well as control the foot pedal to screen. We describe the development of a training simulation model which simulates the human kidney, ureter, and bladder. Methods: Stereolithography (SLA) 3D print technology using SLA resin and Anycubic SLA printer were employed. A plastic tubing was used to connect the 3D printed kidney and bladder as the ureter. This simulation model permits fluoroscopic guided filling of "pelvicalyceal system" with contrast as well as ureteric stenting, guidewire, and drainage catheter manipulation. Effectiveness of the model to attain skills for nephrostomy exchange and ureteric stenting was obtained via questionnaire from trainees prior to and after utilizing the model. Results: The 3D printing simulation model of the kidney, ureter, and bladder system enables trainees to perform nephrostomy exchange, nephrostogram, and antegrade stenting. Participants felt more confident to perform the procedures as they were more familiar with the procedure. Besides that, participants felt their wire and catheter manipulation skills have improved after using the simulation model. Conclusions: Neph-ex simulation model is safe and effective for hands-on training in improving proficiency of fluoroscopy-guided nephrostomy exchange and antegrade ureteric stenting. Advances in knowledge: As of our knowledge, there are no commercially available simulation models for fluoroscopic guided nephrostomy exchange and ureteric stent deployment. No article on nephrostomy exchange simulation model has been published before. [ABSTRACT FROM AUTHOR]

Profitability is a complex notion, intertwined with theoretical, socio-economic, and modern economic considerations. While traditionally linked to monopoly advantages, contemporary views broaden this to include shareholder value creation. In agriculture, profitability faces impediments such as rising input costs, market volatility, and economic disparities, emphasizing technological innovation, market conditions, and policy as crucial determinants. This study presents an econometric simulation model to analyze and forecast wheat production profitability in Poland from 2023 to 2027, providing insights into production efficiencies, market dynamics, and policy impacts. Using a system of recursive equations, the model forecasts profitability, integrating econometric techniques with expert insights. It examines variables like resource use, production levels, and price changes, validated through FADN data. The findings reveal that price relations and production efficiencies are the key to profitability. The model highlights market volatility, particularly through "price scissors", as the main factor influencing profitability. Favorable price conditions significantly boost profitability and incentivize production. The model is a critical tool for analyzing wheat profitability, highlighting the influence of market and policy changes. Future work could extend the model's use to other regions or crops, incorporating advanced technologies to improve accuracy. This study offers valuable insights for agricultural economics, aiding stakeholders in strategic decision-making. [ABSTRACT FROM AUTHOR]

Copyright of Urban Mass Transit is the property of Urban Mass Transit Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Since many ecosystem services involve spatial scales beyond farm size, their preservation and management in agricultural systems depend on the interaction of the landowners. For the analysis of such interactive land use a generic dynamic land‐use model is developed that considers different payoff structures in a systematic manner and relates land‐use dynamics to these payoff structures. A landowner's own payoff depends on the land use on neighboring land parcels. The landowners' payoffs are interpreted in a game‐theoretic manner which allows for a game‐theoretic classification of the different land‐use dynamics generated by the model. The model is analyzed to determine the proportion, spatial aggregation and temporal turnover of land‐use measures. The model results are applied to a number of cases from literature in which the management of ecosystem services involves a regional scale, including pollinator conservation, pest control, and coordination incentives for the conservation of species in fragmented landscapes. Four main domains of model behavior are identified and related to the payoff structures (type of game), characterized by the proportions and temporal turnover of land‐use measures, and by whether the system has one or two stable equilibria. An important determinant of the land‐use dynamics is the spatial heterogeneity of the landowners' payoffs which. It affects the domain and the location in the domain by which the land‐use dynamics are characterized. [ABSTRACT FROM AUTHOR]

Background: Secondary schools are important settings for promoting varied physical activity (PA) opportunities for adolescents to promote PA throughout life. However, research on the effect of secondary school-based interventions on future PA is limited. This study examined the potential impact of secondary school-based interventions on the determinants of future PA participation of Aotearoa New Zealand (NZ) adolescents using simulated modelling. Methods: We used data from a nationally representative sample of secondary school students (n = 5035) aged 12–17 between 2017 and 2020 in NZ. We modelled four secondary school-based interventions and their projected impact on five determinants of future PA. Modelled interventions were the technological augmentation of physical education (TAPE), a peer-led PA mentoring programme (PL), physically active learning (PAL) and the inclusion of a natural environment play area (NE). Results: Total weekly PA increased the most from the NE intervention (+ 0.2 h/week), followed by TAPE (+ 0.08 h/week), PAL (+ 0.05 h/week) and PL (-0.06 h/week). Current number of PA settings increased the most in NE (+ 1.75 settings/week), followed by TAPE (+ 1.29 settings/week), PAL (+ 1.21 settings/week) and PL (+ 0.73 settings/week). Current number of PA types increased the most in NE (+ 1.57 types/week), followed by PL (+ 1.05 types/week), TAPE (+ 0.34 types/week) and PAL (+ 0.15 types/week). Physical literacy scores increased the most from PL (+ 3.6%), followed by PAL (+ 3.3%), TAPE (+ 0.43%) and NE (+ 0.12%). Social support scores increased the most from PAL (+ 5%), followed by PL (+ 1.9%), TAPE (+ 1.46%) and NE (+ 0.57%). Conclusions: On average, all interventions benefitted determinants of future PA participation to a small degree. Results show differing magnitudes of the intervention effect by determinant, indicating the complexities surrounding the promotion of PA adherence. Future interventions could be improved through detailed consultation alongside, and involving, adolescents and stakeholders within schools. Researchers should also prioritise the collection of longitudinal PA data and explore its connection with sociodemographic differences between adolescents. [ABSTRACT FROM AUTHOR]

Introduction: Cost-effectiveness analyses typically ignore healthcare system resource constraints. Ophthalmology is affected by resource constraints because of increasing disease prevalence and the use of resource-intensive treatments. This study evaluated the impact of resource constraints on the cost-effectiveness of faricimab 6 mg, compared with aflibercept 2 mg and ranibizumab biosimilar 0.5 mg, for treating wet age-related macular degeneration (wAMD) or diabetic macular oedema (DMO) over a 5-year horizon. Methods: A microsimulation model estimated the impact of resource constraints on patients visits, delays, costs and quality-adjusted life-year (QALY) losses due to treatment delays at a typical UK National Health Service eye hospital treating 1500 patients with wAMD and 500 patients with DMO. Patient characteristics, treatment regimens and treatment intervals were informed using published literature and expert opinion. Resource constraint was represented by limiting the number of available intravitreal injection appointments per week, with growing demand caused by rising disease prevalence. The model compared outcomes across three scenarios; each scenario involved treating all patients with one of the three treatments. Results: Over 5 years, in a resource-constrained hospital, compared with aflibercept, faricimab use resulted in the avoidance of 12,596 delays, saved GBP/£15,108,609 in cost and avoided the loss of 60.06 QALYs. Compared with ranibizumab biosimilar, faricimab use resulted in the avoidance of 18,910 delays, incurred £2,069,088 extra cost and avoided the loss of 105.70 QALYs, resulting in an incremental cost-effectiveness ratio of £19,574/QALY. Conclusions: Accounting for resource constraints in health economic evaluation is crucial. Emerging therapies that are more durable and require less frequent clinic visits can reduce treatment delays, leading to improved QALY outcomes and reduced burden on healthcare systems. Faricimab reduced the number of delayed injections, leading to improved QALY outcomes for patients in a healthcare system with resource constraints. Faricimab is cost-saving when compared with aflibercept and cost-effective when compared with ranibizumab biosimilar. [ABSTRACT FROM AUTHOR]

The automated material handling system (AMHS) plays a central role in realising smart manufacturing by providing manufacturing facilities with flexible, fast, and precise controls. This paper investigates a new type of AMHS known as the in-line stocker, which not only moves unit loads in manufacturing facilities under processing, similar to the automated-guided vehicle but also stores them on shelves, similar to the automated storage and retrieval system, which can reduce material handling space requirements. However, the traffic rate is very high inside an in-line stocker, and two robots are used along the single lane, which is the dual-robot in-line stocker (DRIS). This paper develops an analytical model to estimate the capacity of the DRIS based on a combined simulation and scheduling method. The simulation analysis shows that the model can be used not only to estimate the precise capacity of a DRIS but also to optimise its operating parameters. [ABSTRACT FROM AUTHOR]

The heating system is an essential component of the glass molding process. It is responsible for heating the glass to an appropriate temperature, allowing it to soften and be easily molded. However, the energy consumption of the heating system becomes particularly significant in large-scale production. This study utilized G-11 glass for the simulation analysis and developed a finite element model for the thermal conduction of a 3D ultra-thin glass molding system, as well as a thermal bending model for smartwatches. Using finite element software, the heat transfer between the mold and the glass was modeled, and the temperature distribution and thermal stress under various processing conditions were predicted. The findings of the simulation, when subjected to a numerical analysis, showed that heating rate techniques significantly affect energy consumption. This study devised a total of four heating strategies. Upon comparison, optimizing with heating strategy 4, which applies an initial heating rate of 35 mJ/(mm2·s) during the initial phase (0 to 60 s) and subsequently escalates to 45 mJ/(mm2·s) during the second phase (60 to 160 s), resulted in a reduction of 4.396% in the system's thermal output and a notable decrease of 7.875% in the heating duration, respectively. Furthermore, a single-factor research method was employed to study the forming process parameters. By comparing the numerical simulation results, it was found that within the temperature range of 615–625 °C, a molding pressure of 25–35 MPa, a heating rate of 1.5–2.5 °C/s, a cooling rate of 0.5–1 °C/s, and a pulse pressure of 45–55 Hz, the influence on residual stress and shape deviation in the glass was minimal. The relative error range was within the 20% acceptable limit, according to the experimental validation, which offered crucial direction and ideas for process development. [ABSTRACT FROM AUTHOR]

Air pollution in megacities worldwide has been a severe public health and environmental problem; it contributes to climate change and threatens life. Among all services, the transport sector accounts for most of these pollutants. However, despite the strategies implemented to reduce these pollutants, mitigate their effects, and promote prosperity and sustainability, emission reduction targets remain unmet, causing the average global temperatures to keep increasing. In this study, the air pollution in the Mexico City Metropolitan Area (MCMA) is estimated through the design of an environmental simulation model using system dynamics, which constitutes a possibility for authorities to foresee the evolution of air quality in MCMA by assessing the emissions from the transport sector from a holistic perspective, based on the region DESTEP analysis factors. Simulation results estimate a more significant reduction than predicted by the local government's current forecast; this emission reduction would be up to 106% lower for PM10, 176% for PM2.5, 34% for NOx, and 17% for VOC. The conclusion demonstrated that one of the main factors with the most significant impact on the control and reduction of emissions is the use and promotion of public transportation, along with the improvement of its road infrastructure. [ABSTRACT FROM AUTHOR]

Objective The dual-bus and dual-interruptible power supply (UPS) architecture in rail transit signaling system power supply enhances the system redundancy but does not effectively reduce component failure rates. To improve the safety and reliability of the rail transit signaling system, it is necessary to develop an intelligent health management system for signal power supply, enabling real-time monitoring, fault diagnosis, and predictive maintenance of signaling system power supply and equipment. Method The design requirements, architecture, module composition, and functions of the intelligent health management system for rail transit signaling system power supply are elaborated in detail. The system is based on real-time monitoring of the operational status for the signaling system power supply or equipment. By understanding the structure and operating principles of the signaling system power supply, the precise simulation and life prediction models are constructed. Functions such as data acquisition, health status analysis, fault diagnosis, and fault prediction are used to implement health management for the signaling system power supply throughout its lifecycle. Result & Conclusion The intelligent health management system for rail transit signaling system power supply utilizes big data processing and mining, applies the AHP (analytic hierarchy process) method and simulation models, aiming to achieve intelligent lifecycle health management of the signaling system power supply, improving reliability and safety while reducing maintenance costs.

Abstract Background Secondary schools are important settings for promoting varied physical activity (PA) opportunities for adolescents to promote PA throughout life. However, research on the effect of secondary school-based interventions on future PA is limited. This study examined the potential impact of secondary school-based interventions on the determinants of future PA participation of Aotearoa New Zealand (NZ) adolescents using simulated modelling. Methods We used data from a nationally representative sample of secondary school students (n = 5035) aged 12–17 between 2017 and 2020 in NZ. We modelled four secondary school-based interventions and their projected impact on five determinants of future PA. Modelled interventions were the technological augmentation of physical education (TAPE), a peer-led PA mentoring programme (PL), physically active learning (PAL) and the inclusion of a natural environment play area (NE). Results Total weekly PA increased the most from the NE intervention (+ 0.2 h/week), followed by TAPE (+ 0.08 h/week), PAL (+ 0.05 h/week) and PL (-0.06 h/week). Current number of PA settings increased the most in NE (+ 1.75 settings/week), followed by TAPE (+ 1.29 settings/week), PAL (+ 1.21 settings/week) and PL (+ 0.73 settings/week). Current number of PA types increased the most in NE (+ 1.57 types/week), followed by PL (+ 1.05 types/week), TAPE (+ 0.34 types/week) and PAL (+ 0.15 types/week). Physical literacy scores increased the most from PL (+ 3.6%), followed by PAL (+ 3.3%), TAPE (+ 0.43%) and NE (+ 0.12%). Social support scores increased the most from PAL (+ 5%), followed by PL (+ 1.9%), TAPE (+ 1.46%) and NE (+ 0.57%). Conclusions On average, all interventions benefitted determinants of future PA participation to a small degree. Results show differing magnitudes of the intervention effect by determinant, indicating the complexities surrounding the promotion of PA adherence. Future interventions could be improved through detailed consultation alongside, and involving, adolescents and stakeholders within schools. Researchers should also prioritise the collection of longitudinal PA data and explore its connection with sociodemographic differences between adolescents.

Eusocial Hymenoptera are often characterized by having facultatively or obligately sterile worker castes. However, findings across an increasing number of species are that some workers are non-natal-they have 'drifted' away from where they were born and raised. Moreover, drifters are often indistinguishable from natal workers in the work and benefits provided to joined groups. This seems an evolutionary paradox of providing benefits to potentially unrelated individuals over close kin. Rather than being mistakes, drifting is proposed to be adaptive if joiners either gain inclusive fitness by preferentially moving to other kin groups or through generalized reciprocity in which exchanging workers across groups raises group-level genetic diversity and creates social heterosis. It is unclear, however, if reciprocity is unlikely because of a susceptibility to cheating. In resolving this question, a series of evolutionary simulations show: (1) Reciprocity can persist under a range of genetic assumptions and scenarios of cheating, (2) cheating almost always evolves, but can be expressed in a variety of ways that are not always predictable, (3) the inclusive fitness hypothesis is equally or more susceptible to cheating. Moreover, existing data in Hymenoptera (although not extensive) are more consistent with generalized reciprocity. This supports a hypothesis that drifting, as a phenomenon, may more often reflect maximization of group and parental fitness rather than fitness gains for the individual drifters.

ABSTRACT: An increasing number of countries are investigating options to stop the spread of the emerging zoonotic infection Salmonella Dublin (S. Dublin), which mainly spreads among bovines and with cattle manure. Detailed surveillance and cattle movement data from an 11-yr period in Denmark provided an opportunity to gain new knowledge for mitigation options through a combined social network and simulation modeling approach. The analysis revealed similar network trends for noninfected and infected cattle farms despite stringent cattle movement restrictions imposed on infected farms in the national control program. The strongest predictive factor for farms becoming infected was their cattle movement activities in the previous month, with twice the effect of local transmission. The simulation model indicated an endemic S. Dublin occurrence, with peaks in outbreak probabilities and sizes around observed cattle movement activities. Therefore, pre- and postmovement measures within a 1-mo time window may help reduce S. Dublin spread.

Abstract Introduction Cost-effectiveness analyses typically ignore healthcare system resource constraints. Ophthalmology is affected by resource constraints because of increasing disease prevalence and the use of resource-intensive treatments. This study evaluated the impact of resource constraints on the cost-effectiveness of faricimab 6 mg, compared with aflibercept 2 mg and ranibizumab biosimilar 0.5 mg, for treating wet age-related macular degeneration (wAMD) or diabetic macular oedema (DMO) over a 5-year horizon. Methods A microsimulation model estimated the impact of resource constraints on patients visits, delays, costs and quality-adjusted life-year (QALY) losses due to treatment delays at a typical UK National Health Service eye hospital treating 1500 patients with wAMD and 500 patients with DMO. Patient characteristics, treatment regimens and treatment intervals were informed using published literature and expert opinion. Resource constraint was represented by limiting the number of available intravitreal injection appointments per week, with growing demand caused by rising disease prevalence. The model compared outcomes across three scenarios; each scenario involved treating all patients with one of the three treatments. Results Over 5 years, in a resource-constrained hospital, compared with aflibercept, faricimab use resulted in the avoidance of 12,596 delays, saved GBP/£15,108,609 in cost and avoided the loss of 60.06 QALYs. Compared with ranibizumab biosimilar, faricimab use resulted in the avoidance of 18,910 delays, incurred £2,069,088 extra cost and avoided the loss of 105.70 QALYs, resulting in an incremental cost-effectiveness ratio of £19,574/QALY. Conclusions Accounting for resource constraints in health economic evaluation is crucial. Emerging therapies that are more durable and require less frequent clinic visits can reduce treatment delays, leading to improved QALY outcomes and reduced burden on healthcare systems. Faricimab reduced the number of delayed injections, leading to improved QALY outcomes for patients in a healthcare system with resource constraints. Faricimab is cost-saving when compared with aflibercept and cost-effective when compared with ranibizumab biosimilar. Graphical Abstract

This paper explores how investments in research and development (R&D) and government policies impact the growth of renewable energy in Brazil, Chile, and Colombia up to 2040. The study presents four scenarios to understand how different levels of R&D investment and the presence or absence of supportive policies affect the spread of renewable technologies such as solar and wind energy. The scenarios range from an optimistic one with high R&D funding and strong policy support to a worst-case scenario with low R&D efforts and weak policies. The findings emphasize the importance of solid government backing and strategic R&D investments in promoting renewable energy and increasing the number of green patents. On the other hand, scenarios with limited policy support and R&D funding show much slower growth, highlighting the challenges posed by economic constraints and tough market conditions. The study shows that strong renewable energy policies could boost renewable energy adoption by 100% to 200%. Overall, this research adds to the discussion on sustainable energy policies and provides useful insights for policymakers and stakeholders to develop strategies that maximize the potential of renewable energy in the region.

Abstract In order to improve the measurement accuracy of mutual inductance parameters of transmission lines in the environment of double circuit power lines without power outage, this paper establishes simulation models for measuring mutual inductance parameters of transmission lines using the different frequency method in two modes: equal and unequal zero sequence self‐parameters of two circuit lines, using a parallel zero sequence coupling model of double circuit power lines. In the article, simulation analysis is conducted on the line parameters with a coupling coefficient between 0.4 and 0.6 and a line length of 20–50 km. In order to further verify the correctness of the simulation model and measurement methods, a test bench was established based on the principle of line mutual inductance parameter testing in a laboratory dual circuit line without a power outage environment for experimental testing. By comparing the test values under experimental conditions with the standard values, it has been proven that the model and method can meet the actual measurement requirements of engineering.

As the realization of carbon neutrality has been a main assignment for coping with the global climate change, it became necessary to analyze upcoming changes in electricity mix with economic and technical viewpoints. This paper presents a newly-developed simulation model that reflects the daily intermittency of renewable energy by applying daily average power supply-demand patterns for each season. Also, the paper provides an economic analysis in the viewpoint of investment cost, annual cost and power generation cost by utilizing the calculations from the simulation model. Four scenarios are selected for the analyses, one based on the Korean Government's 2050 Carbon Neutrality Scenario and three Nuclear Power Build-up scenarios, which are newly suggested by the authors. The simulation results show that the increase of nuclear energy from 5.7% of Government's Scenario to 37.7% of the proposed Nuclear Power Build-up Scenario leads to the decrease of about 704 billion US$ in investment cost and about 181 billion US$ in annual cost; with reduction in the increase of 2050 expected generation cost from 3.1 to 1.6 times compared with the referenced 2021 average cost. Further, this study has significance in performing the economic analysis with the expected daily power supply-demand patterns in 2050.

The utilization of carbon fiber-reinforced polymer/plastic (CFRP) components is primarily limited due to the lack of high-quality and least damage-based hole constructing technology. In this study, the delamination defect is investigated at the exit of CFRP drilling by a novel three-dimensional simulation model considering heat accumulation effect. The validity of the model is confirmed through experimental data of CFRP boreholes: surface temperature distribution at the borehole outlet, drilling axial force, and delamination factor at the outlet. The model exhibited high accuracy in theoretical analysis of CFRP 3D drilling with/without temperature. Additionally, the variation in temperature field and corresponding delamination damage is analyzed through simulation of CFRP drilling process at the exit plane of a hole. Results indicate that delamination damage occurs during unsupported dry drilling when half of the length of the main cutting edge impale the workpiece after reaching its exit plane. The changes in axial force caused delamination under different processing parameters, and a quantitative relationship is established through multiple regression analysis. The appropriate processing parameters can effectively reduce delamination during CFRP drilling. Specifically, accurate measures can ensure sufficient heat conduction and minimize heat accumulation during the formation stages of exit-related delamination. [ABSTRACT FROM AUTHOR]

Introduction: Chemical mass casualty incidents (MCIs) pose a substantial threat to public health and safety, with the capacity to overwhelm healthcare infrastructure and create societal disorder. Computer simulation systems are becoming an established mechanism to validate these plans due to their versatility, cost-effectiveness and lower susceptibility to ethical problems. Methods: We created a computer simulation model of an urban subway sarin attack analogous to the 1995 Tokyo sarin incident. We created and combined evacuation, dispersion and victim models with the SIMEDIS computer simulator. We analyzed the effect of several possible approaches such as evacuation policy ('Scoop and Run' vs. 'Stay and Play'), three strategies (on-site decontamination and stabilization, off-site decontamination and stabilization, and on-site stabilization with off-site decontamination), preliminary triage, victim distribution methods, transport supervision skill level, and the effect of search and rescue capacity. Results: Only evacuation policy, strategy and preliminary triage show significant effects on mortality. The total average mortality ranges from 14.7 deaths in the combination of off-site decontamination and Scoop and Run policy with pretriage, to 24 in the combination of onsite decontamination with the Stay and Play and no pretriage. Conclusion: Our findings suggest that in a simulated urban chemical MCI, a Stay and Play approach with on-site decontamination will lead to worse outcomes than a Scoop and Run approach with hospital-based decontamination. Quick transport of victims in combination with on-site antidote administration has the potential to save the most lives, due to faster hospital arrival for definitive care. [ABSTRACT FROM AUTHOR]

With global economic integration and rapid IT advancements, enterprises face complex market environments and intense competition. Efficient management and coordination of supply chains and manufacturing are critical. This study explores optimization strategies for integrated supply chain and manufacturing management using system dynamics. Initially, it investigates the contractual collaboration model based on system dynamics, analysing dynamic behaviours and optimization strategies. Subsequently, a system dynamics simulation model of the integrated system is constructed. Simulation analysis reveals the interactive relationships and dynamic patterns within the system. While many studies focus on static analysis, they often overlook dynamic changes and complex interactions. This study enriches the theoretical framework and provides solutions for enhancing management efficiency and competitiveness in a volatile market. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. An increasing number of countries are investigating options to stop the spread of the emerging zoonotic infection Salmonella Dublin (S. Dublin), which mainly spreads among bovines and with cattle manure. Detailed surveillance and cattle movement data from an 11-yr period in Denmark provided an opportunity to gain new knowledge for mitigation options through a combined social network and simulation modeling approach. The analysis revealed similar network trends for noninfected and infected cattle farms despite stringent cattle movement restrictions imposed on infected farms in the national control program. The strongest predictive factor for farms becoming infected was their cattle movement activities in the previous month, with twice the effect of local transmission. The simulation model indicated an endemic S. Dublin occurrence, with peaks in outbreak probabilities and sizes around observed cattle movement activities. Therefore, pre- and postmovement measures within a 1-mo time window may help reduce S. Dublin spread. [ABSTRACT FROM AUTHOR]

The paper examines issues concerning the further development of intelligent technology for constructing dynamic integrated expert systems with an emphasis on methods and tools of constructing simulation models of the external environment as an integral stage in the development of dynamic integrated expert systems based on problem-oriented methodology and the AT-TECHNOLOGY workbench. The on-board software complex of the spacecraft is used as an experimental problem domain for prototyping a dynamic integrated expert system. [ABSTRACT FROM AUTHOR]

Copyright of Integrated Intelligent Energy is the property of Editorial Department of Integrated Intelligent Energy and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Farmland use regulation strictly regulates the conversion of agricultural land for other agricultural purposes and the construction of agricultural facilities, thereby optimizing the land use pattern in rural areas. However, different measures and intensities of farmland use regulation can affect the overall performance of green and low-carbon development in rural areas. This study utilizes system dynamics modeling and simulation to conduct a case study based on current land use data from 10 towns in Liyang City, China. The empirical results indicate the following: (1) Based on comprehensive measurements of green and low carbon development performance, Liyang City exhibits a pattern of higher indices in the south and lower indices in the north. Towns such as Tianmu Lake, Daibu, and Shezhu show relatively high average comprehensive indices of 0.31, 0.30, and 0.28, significantly higher than other towns. (2) Simulation of farmland use regulation's impact on green and low carbon development performance reveals that Scenario One, involving additional construction land occupying farmland, achieves a comprehensive index of only 0.23, significantly lower than the other scenarios. (3) Based on calculations and field surveys, Liyang City's villages are categorized into four types, with the largest number being industry-integrated villages (94 villages). Accordingly, policies for farmland use regulation are designed for different village types. Therefore, future farmland use regulation should be tailored with differentiated institutional designs according to the development needs of different villages. This study's findings provide insights into green and low-carbon development in rural areas. [ABSTRACT FROM AUTHOR]

This paper explores how investments in research and development (R&D) and government policies impact the growth of renewable energy in Brazil, Chile, and Colombia up to 2040. The study presents four scenarios to understand how different levels of R&D investment and the presence or absence of supportive policies affect the spread of renewable technologies such as solar and wind energy. The scenarios range from an optimistic one with high R&D funding and strong policy support to a worst-case scenario with low R&D efforts and weak policies. The findings emphasize the importance of solid government backing and strategic R&D investments in promoting renewable energy and increasing the number of green patents. On the other hand, scenarios with limited policy support and R&D funding show much slower growth, highlighting the challenges posed by economic constraints and tough market conditions. The study shows that strong renewable energy policies could boost renewable energy adoption by 100% to 200%. Overall, this research adds to the discussion on sustainable energy policies and provides useful insights for policymakers and stakeholders to develop strategies that maximize the potential of renewable energy in the region. [ABSTRACT FROM AUTHOR]

Flexible manufacturing is an important path for the rapid development of the manufacturing industry. However, there is no specific evaluation standard for the flexibility level of clothing manufacturing, making it difficult for clothing enterprises to estimate the progress of their own flexible manufacturing and the parts that need improvement. In response to this situation, taking S clothing enterprise as an example, the production line balance optimization was taken as the starting point, a three-dimensional evaluation model for flexible manufacturing of clothing was constructed from three aspects; production flexibility, management flexibility, and product flexibility, the flexibility level of S clothing enterprise manufacturing was systematically and comprehensively evaluated. The results indicate that clothing enterprise has a high level of flexible manufacturing and good development prospects. It can continue to improve its existing production mode and further enhance its clothing flexible manufacturing level. The evaluation index system for flexible manufacturing of clothing in this article provides a good foundation and a systematic model for the future flexible manufacturing process and industry standardization of small and medium-sized clothing enterprises, based on the successful practice of S clothing enterprise. [ABSTRACT FROM AUTHOR]

In order to improve the measurement accuracy of mutual inductance parameters of transmission lines in the environment of double circuit power lines without power outage, this paper establishes simulation models for measuring mutual inductance parameters of transmission lines using the different frequency method in two modes: equal and unequal zero sequence self‐parameters of two circuit lines, using a parallel zero sequence coupling model of double circuit power lines. In the article, simulation analysis is conducted on the line parameters with a coupling coefficient between 0.4 and 0.6 and a line length of 20–50 km. In order to further verify the correctness of the simulation model and measurement methods, a test bench was established based on the principle of line mutual inductance parameter testing in a laboratory dual circuit line without a power outage environment for experimental testing. By comparing the test values under experimental conditions with the standard values, it has been proven that the model and method can meet the actual measurement requirements of engineering. [ABSTRACT FROM AUTHOR]

CO2 laser machining is a cost effective and time saving solution for fabricating microchannels on polymethylmethacrylate (PMMA). Due to the lack of research on the incubation effect and ablation behavior of PMMA under high-power laser irradiation, predictions of the microchannel profile are limited. In this study, the ablation process and mechanism of a continuous CO2 laser machining process on microchannel production in PMMA in single-pass and multi-pass laser scan modes are investigated. It is found that a higher laser energy density of a single pass causes a lower ablation threshold. The ablated surface can be divided into three regions: the ablation zone, the incubation zone, and the virgin zone. The PMMA ablation process is mainly attributed to the thermal decomposition reactions and the splashing of molten polymer. The depth, width, aspect ratio, volume ablation rate, and mass ablation rate of the channel increase as the laser scanning speed decreases and the number of laser scans increases. The differences in ablation results obtained under the same total laser energy density using different scan modes are attributed to the incubation effect, which is caused by the thermal deposition of laser energy in the polymer. Finally, an optimized simulation model that is used to solve the problem of a channel width greater than spot diameter is proposed. The error percentage between the experimental and simulation results varies from 0.44% to 5.9%. [ABSTRACT FROM AUTHOR]

The present paper focuses on generating a digital laboratory model at the department by applying the structure from motion technique. The generated digital model is then utilized to create simulation models for application in virtual and augmented reality environments. Nine different approaches to photogrammetric imaging in the laboratory were tested in the experiment. These approaches involved variations in the number of photographs and scanning positions. The results of the experiment were divided into three categories: unsuitable, which required significant modification; incomplete, which required further modification; and suitable, which was directly usable. Some images were unusable due to the similarity of objects in the scene. Experiments showed that some parts of the laboratory were more appropriate to image separately. It was also found that dark and shiny surfaces of objects presented a problem for the computation of the models. Therefore, it was necessary to use markers or colours to eliminate this problem. [ABSTRACT FROM AUTHOR]

With recent outbreaks of foot‐and‐mouth disease (FMD) in Indonesia and Bali, industry, government and public concern for its incursion into Australia is increasing. The potential impact of an outbreak on the agricultural industry and national economy could be devastating. To date, research conducted in relation to FMD in Australia predominantly concerns simulations and models performed to predict various outcomes. This project critically appraises the current literature regarding the simulated use of vaccination and its effectiveness for controlling the spread of FMD in Australia in the event of an outbreak. Findings from 10 modelling studies suggest that vaccination is effective at controlling the size and duration of an outbreak (under certain conditions), however, there is less clarity about cost‐effectiveness. [ABSTRACT FROM AUTHOR]

Current research on overvoltage in trains can be divided into field tests and circuit simulations. The circuit simulation study focuses on the overvoltage amplitude distribution, the oscillation frequency of the main operating overvoltage is also an important characteristic, and the amplitude and frequency characteristics of the overvoltage need to be considered in the study of its suppression method. However, there is currently limited research on the frequency distribution of overvoltage. To provide guidance for the study of overvoltage suppression in the operation of the main circuit breaker, a new simulation model of train operating main break overvoltage is proposed based on the three-dimensional structure of the car body, high-voltage cables and rails. The model is used to simulate the transient overvoltage characteristics of the high-voltage cable core and each car body during the operation of the main circuit breaker, and the distribution of the overvoltage in each car body is obtained. The simulation results show that the maximum overvoltage amplitude during the operation of car 1 is 6.10 kV, while it is the smallest for car 4. The overvoltage amplitudes of cars 1 to 4 are all above 1 kV, and it was found that there are two main oscillation frequencies of the main overvoltage during the operation of the car body, which are 0.70 MHz and 1.30 MHz. Furthermore, the accuracy of the distribution characteristics and spectral characteristics of the train operating main break overvoltage is verified by static tests on the existing trains, and the test data show that the simulation results are extremely accurate in terms of overvoltage amplitude distribution, and the error between simulation and test does not exceed 5% in terms of amplitude, except for car 4. In terms of spectral characteristics, both simulation and experiment have two main oscillation frequencies, which can be considered consistent between simulation and experiment. Therefore, it can be concluded that the simulation model based on the three-dimensional structure has the ability to simulate the characteristics of operating overvoltage with high accuracy and provides guidance for overvoltage suppression research. [ABSTRACT FROM AUTHOR]

Rationale: Reducing the risk of exacerbation is a fundamental goal in managing stable chronic obstructive pulmonary disease (COPD). Guidelines recommend triple therapy (inhaled corticosteroids, long-acting muscarinic antagonists, and long-acting β-agonists) only as a stepup from dual therapy (long-acting muscarinic antagonists and long-acting β-agonists) for patients at continued high risk of exacerbation, because of the trade-off of an increased risk of pneumonia associated with inhaled corticosteroid–containing therapies. However, there is little evidence on the optimum timing of initiating triple therapy. Objectives: To perform a benefit–harm analysis to evaluate the net benefit of earlier initiation of triple therapy for the prevention of acute exacerbations in patients with COPD compared with standard timing recommended in current guidelines. Methods: We used a validated whole-disease microsimulation model of COPD in the Canadian general population aged ⩾40 years to determine the benefit versus harm of earlier initiation of triple therapy over a 20-year time horizon compared with standard care. We assessed net change in quality-adjusted life-years (QALYs) from the reduction in risk of acute exacerbations and the increased risk of treatment-related pneumonia in subgroups of patients with COPD defined by exacerbation history, symptoms, and disease severity. Model parameters were determined from clinical trials and other published literature. Key parameters were varied in one-way sensitivity analysis. Results: In patients at high risk of acute exacerbation (54.7% female; mean age, 74.0 yr; 68% Global Initiative for Chronic Obstructive Lung Disease grades I and II), earlier initiation of triple therapy was associated with a net QALY gain of 4.8 per 100 patients with COPD over 20 years compared with standard care. The net QALY gain increased to 5.9 per 100 patients in the subgroup of patients with a high symptom burden (modified Medical Research Council dyspnea scale score, >1). Earlier initiation remained net beneficial in all subgroup and sensitivity analysis scenarios. Conclusions: Modeling suggests that earlier initiation of triple therapy is likely to be net beneficial for patients at high risk of acute exacerbation, with an even greater benefit to patients with a high symptom burden. Further clinical research is needed to verify these findings in empirical studies. [ABSTRACT FROM AUTHOR]

Purpose: To study the published literature for various models used for simulation and training in the field of pediatric colorectal surgery. Method: A PubMed search was conducted for studies of simulation models in anorectal malformation on 24 March 2024 with the search words 'simulation pediatric colorectal surgery' followed by another search on 'simulation AND anorectal malformation' that gave 22 and 14 results, respectively (total 36). After removing 4 duplicate publications, 12 were found relevant to simulation and training in colorectal diseases. One publication relevant to the topic was added from literature, thirteen articles were studied. Results: Of these, 5; 1; 4; and 3 were on inanimate models; animate model; 3D reconstructions; and training, respectively. Simulation models are available for posterior sagittal anorectoplasty. The same inanimate model was used in five articles. The animate model was based on a chicken cadaver. 3D models have been made for personalized preoperative assessment and to understand the imaging in anorectal malformation. One 3D model was made by regeneration of organoid epithelium. Training modules were made to evaluate surgical dissection, standardize surgical techniques, and improve proficiency. Conclusion: Simulation models are an important tool for teaching the steps of surgery and discussing the nuances of operative complications among mentors and peers. With advances in this field, the development of high-fidelity models, more training modules, and consensus on surgical techniques will benefit surgical training. [ABSTRACT FROM AUTHOR]

Context: The number of publications that evaluate or use landscape connectivity has grown dramatically in recent years. But the biological realism of common connectivity assessments remains limited. To address this shortcoming, I introduce a flexible methodology for evaluating functional landscape connectivity that can be quick to implement, biologically nuanced, and straightforward to interpret. Methods: I combined a US Fish and Wildlife Service land cover map with information from existing empirical studies to develop a movement simulator for the Fender's blue butterfly, an endangered species in Oregon, USA. I use the resulting butterfly model to explore the concepts and mechanics behind my novel connectivity assessment methodology. Results: My methods are able to identify clusters of connected resource patches, quantify and visualize movement rates between patches, and identify opportunities for enhancing connectivity through restoration and mitigation. My results include an emergent dispersal kernel that captures the influence of movement behavior on connectivity. Discussion: The methods I introduce are capable of generating detailed yet practical connectivity analyses that can incorporate considerable biological and behavioral realism. My approach is simple to implement, and the requisite data can be modest. The toolkit I developed has the potential to standardize connectivity assessments that use either real or simulated movement data. [ABSTRACT FROM AUTHOR]

This study investigated the economic performance of pastoralist small ruminant flocks in Kajiado county, Kenya, and the financial impact of mortalities and changes in performance indicators. A survey of 129 pastoralist small ruminant flocks captured production and economic data for a 12-month period via interview. Simulation models were then developed for flocks with different performance levels and trading activities. Their gross margins, and the financial impact from mortalities, were estimated. Sensitivity analyses were conducted for select performance indicators to assess their relative economic importance. On average, pastoralists who were not purchasing supplementary feed (79% of flocks) had gross margins of KSh 3,016 - KSh 3,123 per reproductive female. Goat production generated 2.43-2.51 times greater returns than sheep production. High efficiency mixed flocks achieved 2.04-2.06 times greater returns than medium efficiency flocks, and 12.19-14.25 times greater returns than low efficiency flocks. Pastoralist-only flocks had 3.82-4.01 times greater returns than pastoralist-traders. Financial losses due to mortality were on average 17.81% of the starting flock value. Fecundity and abortion rates in sheep, and parturition rate in goats, had the greatest economic impact. The developed models could support decision-making toward improving the economic performance of pastoralist flocks and the evaluation of interventions and external shocks. [ABSTRACT FROM AUTHOR]

The article presents simulation modeling as a mathematical basis for the study of logistic systems. The object is pharmaceutical logistics - logistics chains of pharmaceutical companies. Attention is focused on the problems of functioning of domestic pharmaceutical logistics in the conditions of military realities. The expediency of using simulation modeling technologies to reproduce the changing, force majeure conditions of functioning of the supply channels of finished pharmaceutical products is substantiated. Models of one-level and two-level sales channels for pharmaceutical products, built using the discrete-event simulation paradigm on the software platform of the AnyLogic system, are presented. The results of the simulation are illustrated by fragments of simulation experiments based on the materials of the pharmaceutical company FARMAK. [ABSTRACT FROM AUTHOR]

This experiment was designed to study the surface defects of 20 % volume fraction SiCp/Al composites after grinding and to provide the necessary experimental results for optimizing grinding parameters. Based on the two-dimensional cutting simulation model of single particle, the main damage of particles in matrix during machining has been investigated. The particles in SiCp/Al composites are randomly distributed and the tool will cut through multiple particles in a single cut and at different locations. A single particle cutting model was developed to study the different states of particle fragmentation by cutting through the upper, middle and lower parts of the particles respectively. Nine groups of parameters were obtained by orthogonal experimental design, and electroplated diamond grinding rod was used as the grinding tool for grinding experiment. In order to get the best surface grinding parameters, a ternary linear regression equation was selected to be established. Significance test could prove the reliability of the linear regression equation, and then, the optimal solution of this equation can be calculated by the MATLAB genetic algorithm toolbox. From the simulation and experimental results, it can be seen that the stress begins to concentrate when the cutting tool is close to the particle, and when the cutting stress exceeds the ultimate compressive strength, the particle is broken and part of it will be pulled out. The breakage of particles is not one-time, but requires many times of large cutting force to break the particles in sections, and the repeated breakage of particles eventually leads to the generation of overall cracks. [ABSTRACT FROM AUTHOR]

Proactive prevention and fighting fire at industrial facilities, often located in urbanized clusters, should include the use of modern methods for modeling danger zones that appear during the spread of the harmful combustion products of various chemicals. Simulation modeling is a method that allows predicting the parameters of a danger zone, taking into account a number of technological, landscape, and natural-climatic factors that have a certain variability. The purpose of this research is to develop a mathematical simulation model of the formation process of a danger zone during an emergency at an industrial facility, including an explosion of a container with chemicals and fire, with the spread of an aerosol and smoke cloud near residential areas. The subject of this study was the development of a simulation model of a danger zone of combustion gases and its graphical interpretation as a starting point for timely decision making on evacuation by an official. The mathematical model of the process of danger zone formation during an explosion and fire at an industrial facility presented in this article is based on the creation of a GSL library from data on the mass of explosion and combustion products, verification using the Wald test, and the use of algorithms for calculating the starting and ending points of the danger zone for various factor values' variables, constructing ellipses of the boundaries of the distribution of pollution spots. The developed model makes it possible to calculate the linear dimensions and area of the danger zone under optimistic and pessimistic scenarios, constructing a graphical diagram of the zones of toxic doses from the source of explosion and combustion. The results obtained from the modeling can serve as the basis for making quick decisions about evacuating residents from nearby areas. [ABSTRACT FROM AUTHOR]

Radio frequency energy harvesting RFEH technology has been applied widely in the development of wearable electronic power supply systems because of its eco-friendly and highly efficient characteristics. In the RFEH system the receiving antenna collects electromagnetic waves through electromagnetic coupling technology. Obviously the receiving antenna plays a crucial role in the energy harvesting efficiency of the RFEH system. Generally the antenna performance can be optimized by simulation and measurement. In the simulation of screen-printed fabric-based antenna for RFEH the establishment of a precise structure model of the substrate fabric is the basis for the simulation analysis. However in order to save the calculation cost most studies ignore the interwoven structural characteristics of the fabric in establishing a simulation model which leads to a big difference between the simulation and measurement results. To guide the actual product design and engineering application evaluation through the simulation of fabric-based antennas it is necessary to establish a fabric-based antenna model with high simulation accuracy and low calculation cost. To obtain the structural model of screen-printed woven fabric-based antenna for RFEH with high accuracy and low calculation cost this study constructed six different simplified structural models of filament woven fabrics firstly including interwoven meso-structure hole combining concave-convex structure hole structure plane concave-convex structure curved concave-convex structure and uniform structure. The interaction mechanism between the woven fabric and the electromagnetic wave was simulated. Based on this the antenna performance with different simulated structural substrates was analyzed parametrically with porosity and roughness as variables. And then several antennas with different simplified structural substrates were prepared to verify the feasibility of the simplified structural model of the substrate in the design of the antenna for RFEH. The results show that the interwoven meso-structure can be equivalent to a model with holes and / or a concave-convex structure model by comparing the reflectivity and transmittance. And the antenna radiation performance gain and efficiency with the uniform substrate structural model are significantly high. In addition the structure model with a rough surface has a more significant effect on the antenna performance than the non-rough surface structure model. Furthermore the model prediction and measured results of the antenna RFEH performance in the ultra-high frequency UHF range were compared. It is found that there is no significant difference between the two and there is no significant difference among different simplified structure models. The maximum transmission distance of the antenna reaches 220 cm and the received signal strength indication RSSI of unit area at 1 m distance exceeds 8. 442 mW/ cm². The output voltage and power conversion efficiency of the antenna are up to 135 mV and 60% respectively. Consequently in order to save the calculation cost the filament plain woven fabric substrate with a porosity of less than 30% and a roughness of less than 5. 39 μm can be equivalent to a uniform medium model in the simulation of screen-printed antenna for RFEH in the ultrahigh frequency range. An effective simulation method for woven fabric-based printed antenna for radio frequency energy harvesting in the ultra-high frequency range with high accuracy and low computational cost is provided by simplifying the fabric structure of holes and surface texture features. This method of model simplification has certain reference meanings for the model simplification of the antenna with complex structure applied to other fields. Furthermore this high-precision simulation model contributes to predicting the performance of the fabric-based antenna and optimizing the design of the fabric-based antenna so that fabric-based RFEH antennas can be applied to more extensive fields. [ABSTRACT FROM AUTHOR]

A current challenge of irrigationengineering is to modernize surface irrigation. For example, surge flow irrigation has the potential to increase the efficiency of applying irrigationwater. The objective of this study was to perform a sensitivity analysis using the performance indices: Application Efficiency (AE), Storage Efficiency (SE), Distribution Efficiency (DE), Deep Percolation (DP), and Runoff (RO), and to investigate their relationship with the main system variables: length (L), unit flow rate (Qo), surge cycles and surge time, using the SIRMOD model. The SIRMOD model simulates the hydraulics of surface irrigation at the field level. The model with the best fit of AE, DE, DP, and RO as a function of L, Qo, or surge cycles and surge time was a quadratic polynomial function with an R2 > 0.70. The model reflects the goodness of fit to the variable that is intended to be explained. The AE is an increasing function of L and a decreasing function of Qo, while DE and RO are decreasing functions of L and are increasing functions of Qo. The number of surges has an impact on the stream size of each surge and on the volume of water stored, but not on the performance indices. It was demonstrated that the SIRMOD model provided the ability to adjust the system parameters and design variables, giving answersto any surge flow configuration. The potential application efficiency (AEpot) (>80%) can be achieved by establishing, e.g., an optimal flow rate (Qopt), with a schedule for the cycle number and surge time, according to soil characteristics. [ABSTRACT FROM AUTHOR]

Adding nanoparticles to different diesel fuel blends may be an efficient way to reduce pollutant emissions and improve the performance and efficiency of diesel engines. The use of nanoparticles as additives in diesel fuel impacts the jet development within the engine combustion chamber, but its mechanism is still not enough understood. The goal of this research paper was to evaluate some of the jet characteristics, such as spray penetration, cone angle, and Sauter mean diameter, which are greatly involved in fuelair mixture formation. Based on the fuel properties before and after the addition of CeO2 nanoparticles in fuel, information existing in dedicated literature, the actual results were obtained with the AVL Hydsim v2021.1 simulation tool. The reference fuel used in this study was the Diesel-Ethanol blend DE20, consisting of 80% vol. diesel fuel and 20% vol. ethanol in the Diesel-Ethanol mixture. Compared to the original DE20 fuel blend, the highest fraction of CeO2 nanoparticles (100 ppm in fuel) led to an 8.2% reduction in penetration, a 9.5% decrease in cone angle, and a 6.1% increase in Sauter mean diameter at the reference event represented by the start of combustion moment.. [ABSTRACT FROM AUTHOR]

Objective: To compare the effectiveness of administering inferior alveolar nerve blocks (IANB) for the first time with or without a previous practical lesson using a simple manufactured simulator. Methods: This was a study designed to compare students' first administration of IANB anesthesia during 2022, with or without a previous practical lesson. Students were randomized into two groups. The experimental group attended both theoretical lessons and a practical lesson with a simulator device, while the control group attended only theoretical lessons. The theoretical lesson included usual contents such as anatomy, physiology, technical maneuvers for administering anesthesia, tips, and complications, and the practical lesson consisted of the administration of anesthesia using a simple manufactured simulator. After students applied their first IANB, its efficacy, and their answers to a questionnaire on a 5‐point Likert scale were recorded. Statistical analysis consisted of the Chi‐square test (p < 0.05). Results: The study recorded 60 anonymous surveys. The main difference observed was in instrument handing (p < 0.05), and there was a tendency in the ease of recognition of the anatomical marks used for the technique—pterygomandibular raphe and coronoid notch of the mandible (p = 0.08 and 0.11, respectively). No difference in success was observed (p > 0.05). Self‐confidence and personal feelings did not differ statistically. All students agreed strongly or partially that training with the simulator model was helpful. Conclusion: Students who used simple manufactured simulators achieved better outcomes for instrument handling, and possibly for identification of anatomical landmarks, than those who received only theoretical lessons. [ABSTRACT FROM AUTHOR]

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A comprehensive mathematical model of a small hydroelectric power plant for a simulation modelling system has been developed. The model consists of the following simulation mathematical models: a hydraulic turbine with an adjustable guide device, its hydraulic network, an electromechanical system, and a reservoir model. These simulation models are based on the differential equations of electrical, mechanical, and hydraulic equilibrium and are designed to determine the values of currents, speeds, and performance of steady-state operating modes, taking into account the nonlinear properties of the equation parameters. To improve the adequacy of the complex model, a refined simulation model of an induction machine with loss detailing was applied and verified to specify the efficiency and permissible heating power in the motor and generator modes. The losses in steel are ac-counted for by their equivalent circuits. The information on the calculated values of the operating mode parameters allows deter-mining the value of the efficiency indicators of the hydroelectric power plant system under different operating conditions, which makes it possible to formulate optimal modes. Based on the results of a series of calculations with varying static head and open-ing of the blades of the axial guide apparatus, the regularities of changes in their optimal ratio according to the criterion of maximum electric power generated per unit of reservoir water flow used in the formation of the power plant's shunting mode were investigated. Based on the information on the value of the natural flow and the characteristics of the turbine unit, a stable level of static head is determined, which ensures the maximum generated electric power. The power plant's shunting mode was studied to determine the impact of changing the number of simultaneously operating units on the amount of electricity generated and changes in its capacity (the possibility of reducing the unevenness of the generated power by almost two times and increasing the minimum capacity by 30% was shown). Compared to the steady-state flow, the shunting mode provides an almost twofold increase in electricity generation and a threefold increase in efficiency, taking into account the differential cost of electricity by time of day. [ABSTRACT FROM AUTHOR]

The aim of this research is to devise a continuous simulation model for predicting ship crane failures to increase their reliability and reduce unplanned downtime during cargo loading and unloading operations. To predict the condition of the hydraulic system, a database from the GALIOT software package was used for carrying out maintenance on cranes at m/v "O" over a period of 120,000 working hours. In the research, fault tree analysis (FTA) was used to identify causal relationships between system failures and basic events, while the Markov mathematical model was used to model the system state and predict transitions between different failure states. A system dynamics simulation model was developed to simulate the behavior of a system using POWERSIM PowerSim Constructor 2.5.d (4002), and regression analysis was performed to analyze the simulation results and understand the relationships between dependent and independent variables. The results show that a model for predicting failures in the hydraulic motors and pumps of ship cranes was developed, and the Markov model makes it possible to estimate the frequency of transitions between states under the condition that the sum of reliability equals one. The simulation model shows high reliability of the cranes and a constant frequency of failures throughout the 120,000 operating hours, while the regression analysis confirms the validity of the simulation model and shows a strong correlation between the analyzed variables. These models are used to improve the planning of ship crane maintenance, reduce unplanned downtime, and predict and promptly detect failures, which overall minimizes maintenance costs and failures. [ABSTRACT FROM AUTHOR]

Radioisotope thermophotovoltaic systems can provide reliable and long-lasting power for space exploration or other applications. In this research, the feasibility and potential application of radioisotope thermophotovoltaic systems with milliwatt-level output power were investigated. Using 5 W241AmO2 ceramic material as the heat source, a comprehensive simulation model was established through optimization of the heat source shape, insulation structure, and selected emitter, filter, and photovoltaic cells. The heat distribution characteristics of a milliwatt-level radioisotope thermophotovoltaic system in a high-temperature vacuum environment were simulated and analyzed in detail. By optimizing the optical cavity and multilayer insulation design, the emitter temperature was maintained above 800 °C, achieving a system efficiency close to 9 % and an output power of 0.4484 W. The impact of different emitters on the system was also analyzed, revealing that nanostructure emitters can increase the system conversion efficiency by more than 30 %. This work provides a reference for designing milliwatt-level radioisotope thermophotovoltaic systems and has important research value and application prospects.

CGN Delingha 50MW parabolic trough solar power plant is China's first commercial trough solar power station. There are 190 heat collecting loops in the solar field of the power plant. Due to the mutual coupling of heat collecting loops layout location, environmental conditions, medium flow, working medium physical property changes and other factors, the hydrodynamic characteristics of the solar field are complex. In practical operation, balancing the flow of the heat absorbing medium in each loop of the large-scale trough solar thermal power plant and stabilizing the outlet medium temperature are difficult problems. Taking CGN Delingha 50MW parabolic trough solar power plant as the research object, this paper adopts the idea of modular modeling to establish the mathematical model of the main equipment in different systems of the power plant, to build the dynamic model of its solar field, steam generation system, heat storage system and steam turbine system. Based on the parallel computing function of the real-time dynamic simulation platform STAR-90, the real-time coupling calculation between different systems is realized. The error of the built model in steady-state is less than 2%, and the dynamic results of the model are in good agreement with the actual operation data. The modeling method in this paper is universal and can be a reference for dynamic modeling of other large-scale trough solar thermal power plants.