In current China, the main problem existing in the rural public goods supplying system is the unbalanced condition of public goods supply, and the chief reason for which is unitary system of supply main body. Thus the...In current China, the main problem existing in the rural public goods supplying system is the unbalanced condition of public goods supply, and the chief reason for which is unitary system of supply main body. Thus the leading countermeasure for comer of public goods supply is to reform the present unitary rural public goods supplying system, to strengthen functional transfer of rural grass-roots directive organization, to adopt diversified mode and provide public goods on the base of overall planning of urban and rural areas and to implement unitary and diversified supplying strategy. In this way, supplying efficiency of the rural public goods will be improved.展开更多
Background: The availability of essential medicines and medical supplies is crucial for effectively delivering healthcare services. In Zambia, the Logistics Management Information System (LMIS) is a key tool for manag...Background: The availability of essential medicines and medical supplies is crucial for effectively delivering healthcare services. In Zambia, the Logistics Management Information System (LMIS) is a key tool for managing the supply chain of these commodities. This study aimed to evaluate the effectiveness of LMIS in ensuring the availability of essential medicines and medical supplies in public hospitals in the Copperbelt Province of Zambia. Materials and Methods: From February to April 2022, a cross-sectional study was conducted in 12 public hospitals across the Copperbelt Province. Data were collected using structured questionnaires, checklists, and stock control cards. The study assessed LMIS availability, training, and knowledge among pharmacy personnel, as well as data accuracy, product availability, and order fill rates. Descriptive statistics were used to analyse the data. Results: All surveyed hospitals had LMIS implemented and were using eLMIS as the primary LMIS. Only 47% and 48% of pharmacy personnel received training in eLMIS and Essential Medicines Logistics Improvement Program (EMLIP), respectively. Most personnel demonstrated good knowledge of LMIS, with 77.7% able to log in to eLMIS Facility Edition, 76.6% able to locate stock control cards in the system, and 78.7% able to perform transactions. However, data accuracy from physical and electronic records varied from 0% to 60%, and product availability ranged from 50% to 80%. Order fill rates from Zambia Medicines and Medical Supplies Agency (ZAMMSA) were consistently below 30%. Discrepancies were observed between physical stock counts and eLMIS records. Conclusion: This study found that most hospitals in the Copperbelt Province of Zambia have implemented LMIS use. While LMIS implementation is high in the Copperbelt Province of Zambia, challenges such as low training levels, data inaccuracies, low product availability, and order fill rates persist. Addressing these issues requires a comprehensive approach, including capacity building, data quality improvement, supply chain coordination, and investment in infrastructure and human resources. Strengthening LMIS effectiveness is crucial for improving healthcare delivery and patient outcomes in Zambia.展开更多
For any country,the availability of electricity is crucial to the development of the national economy and society.As a result,decision-makers and policy-makers can improve the sustainability and security of the energy...For any country,the availability of electricity is crucial to the development of the national economy and society.As a result,decision-makers and policy-makers can improve the sustainability and security of the energy supply by implementing a variety of actions by using the evaluation of these factors as an early warning system.This research aims to provide a multi-criterion decision-making(MCDM)method for assessing the sustainability and security of the electrical supply.The weights of criteria,which indicate their relative relevance in the assessment of the sustainability and security of the energy supply,the MCDM method allow users to express their opinions.To overcome the impact of uncertainty and vagueness of expert opinion,we explore the notion of picture fuzzy theory,which is a more efficient and dominant mathematical model.Recently,the theory of Aczel-Alsina operations has attained a lot of attraction and has an extensive capability to acquire smooth approximated results during the aggregation process.However,Choquet integral operators are more flexible and are used to express correlation among different attributes.This article diagnoses an innovative theory of picture fuzzy set to derive robust mathematical methodologies of picture fuzzy Choquet Integral Aczel-Alsina aggregation operators.To prove the intensity and validity of invented approaches,some dominant properties and special cases are also discussed.An intelligent decision algorithm for the MCDM problem is designed to resolve complicated real-life applications under multiple conflicting criteria.Additionally,we discussed a numerical example to investigate a suitable electric transformer under consideration of different beneficial key criteria.A comparative study is established to capture the superiority and effectiveness of pioneered mathematical approaches with existing methodologies.展开更多
Rice straw,a by-product of rice cultivation,is commonly disposed of through open-field burning,which contributes to air pollution and environmental degradation.This study aims to identify the key factors influencing f...Rice straw,a by-product of rice cultivation,is commonly disposed of through open-field burning,which contributes to air pollution and environmental degradation.This study aims to identify the key factors influencing farmers’decisions on rice straw management and to develop policy recommendations that encourage the sustainable utilization of rice straw within the supply chain.A mixed-methods approach was adopted,combining qualitative interviews with nine key informants and a quantitative survey of 585 rice farmers across Thailand.Multinomial Logit Regression(MLR)was employed to analyze farmers’preferences among four management options:burning,composting,animal feeding,and selling.The results reveal that membership in farmer groups,ownership of livestock,access to baling machinery,knowledge,and skills related to straw utilization,ease of field access,availability of storage facilities,engagement in integrated farming,and year-round access to baling services significantly increased the likelihood of choosing sustainable alternatives over the burning straw.These findings underscore the importance of both capacity-building and infrastructure in enabling sustainable practices.Based on these insights,the study proposes a multi-level policy framework to enhance the value creation of rice straw.National policies should focus on expanding access to machinery and supporting innovation,while local governments should facilitate farmer training and improve straw logistics.Strengthening farmer organizations and market connections is also crucial for scaling adoption.Overall,structural integration and stakeholder coordination are key to reducing straw burning and promoting sustainable resource use in rice-producing regions.展开更多
Purpose–Adding an appropriate pre-sag to the geometry of simple catenary systems for electric railways can improve their performance in dynamic interaction with the pantographs of trains operating under them.The valu...Purpose–Adding an appropriate pre-sag to the geometry of simple catenary systems for electric railways can improve their performance in dynamic interaction with the pantographs of trains operating under them.The value of pre-sag can be obtained by empirical approximation or computationally expensive optimisation.This study aims to define a simple but accurate method to determine a suitable pre-sag without dynamic simulations and to find its limitations.Design/methodology/approach–A quasi-static method to determine the ideal value of pre-sag is described based on elasticity variations.It considers variations of the static contact force.The limits of this method are investigated by comparing it to a parametric dynamic simulation study.In the dynamic simulation,an optimal level of pre-sag is identified for each contact force level.The influence of the speed in the dynamic simulation results is expressed in two parameters:the quasi-static influence in the mean contact force and the dynamic influence in the ratio between the vehicle speed and the wave propagation speed in the contact wire.Findings–The comparison between the suggested method and the dynamic simulations shows a high consistency up to a speed limit of around 40%of the wave propagation speed.The best agreement with the dynamic results is achieved by calculating the optimal pre-sag based on the absolute elasticity variation.Practical implications–The simplified approach for determining the pre-sag is valid for low-speed applications,such as suburban railway lines.For these cases,a highly suitable geometry can be obtained with the suggested method,meaning a significantly reduced computational effort.As a case study for this work,the results are applied to a Swedish suburban rail line upgrade case.Originality/value–The static uplift force is added as a varied parameter in dynamic simulations.The shift in system behaviour from low to high dynamics is described,and how the benefits from pre-sag are visible and then disappear.The limit value of the low-dynamics regime is identified to be 40%.展开更多
Critical for metering and protection in electric railway traction power supply systems(TPSSs),the measurement performance of voltage transformers(VTs)must be timely and reliably monitored.This paper outlines a three-s...Critical for metering and protection in electric railway traction power supply systems(TPSSs),the measurement performance of voltage transformers(VTs)must be timely and reliably monitored.This paper outlines a three-step,RMS data only method for evaluating VTs in TPSSs.First,a kernel principal component analysis approach is used to diagnose the VT exhibiting significant measurement deviations over time,mitigating the influence of stochastic fluctuations in traction loads.Second,a back propagation neural network is employed to continuously estimate the measurement deviations of the targeted VT.Third,a trend analysis method is developed to assess the evolution of the measurement performance of VTs.Case studies conducted on field data from an operational TPSS demonstrate the effectiveness of the proposed method in detecting VTs with measurement deviations exceeding 1%relative to their original accuracy levels.Additionally,the method accurately tracks deviation trends,enabling the identification of potential early-stage faults in VTs and helping prevent significant economic losses in TPSS operations.展开更多
Hydraulic control valves, positioned at the terminus of pipe networks, are critical for regulatingflow and pressure, thereby ensuring the operational safety and efficiency of pipeline systems. However,conventional val...Hydraulic control valves, positioned at the terminus of pipe networks, are critical for regulatingflow and pressure, thereby ensuring the operational safety and efficiency of pipeline systems. However,conventional valve designs often struggle to maintain effective regulation across a wide range of systempressures. To address this limitation, this study introduces a novel Pilot hydraulic valves specificallyengineered for enhanced dynamic performance and precise regulation under variable pressure conditions.Building upon prior experimental findings, the proposed design integrates a high-fidelity simulationframework and a surrogate model-based optimization strategy. The study begins by formulating acomprehensive mathematical model of the pipeline system using electro-hydraulic simulation techniques,capturing the dynamic behavior of both the pilot valve and the broader urban water distribution network. Acoupled simulation platform is then developed, leveraging both one-dimensional (1D) and three-dimensional(3D) software tools to accurately analyze the valve’s transient response and operational characteristics. Toachieve optimal valve performance, a multi-objective optimization approach is proposed. This approachemploys a Levy-based Improved Tuna-InspiredWake-Up Optimization Algorithm (L-TIWOA) to refine aBackpropagation (BP) neural network, thereby constructing a highly accurate surrogate model. Compared tothe conventional BP neural network, the improved model demonstrates significantly reduced mean absoluteerror (MAE) and mean squared error (MSE), underscoring its superior predictive capability. The surrogatemodel serves as the objective function within an Improved Multi-Objective Mother Lode OptimizationAlgorithm (IMOMLOA), which is then used to fine-tune the key design parameters of the control valve.Validation through experimental testing reveals that the optimized valve achieves a maximum flow deviationof just 1.11 t/h, corresponding to a control accuracy of 3.7%, at a target flow rate of 30 t/h. Moreover,substantial improvements in dynamic response are observed, confirming the effectiveness of the proposeddesign and optimization strategy.展开更多
This article focuses on the optimization of water supply and drainage systems,involving theories such as hydraulic models of pipeline systems and multi-objective collaborative optimization.It introduces the system dyn...This article focuses on the optimization of water supply and drainage systems,involving theories such as hydraulic models of pipeline systems and multi-objective collaborative optimization.It introduces the system dynamics model of sewage treatment facility expansion.Elaborating on detection technology,construction of an intelligent operation and maintenance system,and factors to be considered for sewage plant expansion,it emphasizes the importance of collaborative development and verifies benefits through the PSR model.展开更多
The liquid nitrogen(LN2)supplying system,one of the four key systems of the cryogenic wind tunnel(CWT),is an essential guarantee for the precise control,fast and safe regulation of the wind tunnel’s total temperature...The liquid nitrogen(LN2)supplying system,one of the four key systems of the cryogenic wind tunnel(CWT),is an essential guarantee for the precise control,fast and safe regulation of the wind tunnel’s total temperature.Firstly,the technical schemes,advantages and disadvantages of different LN2 supplying systems are discussed and analyzed based on the operation conditions and test requirements of different CWTs.Then,together with the development of the pilot cryogenic transonic wind tunnel(PCTW),the key technologies of the system,including the supplying mode,rapid and accurate regulation of injection pressure,development of large scale cryogenic centrifugal pump,and matching technology between pumps and pipe network,have been summarized and the solutions to the existing issues are given.Finally,a supplying process suitable for large-scale CWT is proposed,which has the ability of independent commissioning,rapid regulation,accurate control of injection pressure and transient response to the wind tunnel’s wide range of working conditions.The breakthrough in LN2 supplying system enables China to construct a CWT for the future competitive high Reynolds number aircraft.展开更多
Transgression networks in metropolitan centers need to supply a large quantity of power in a reliable manner to vital loads that are located within. A transmission network supplying such an important area must have a ...Transgression networks in metropolitan centers need to supply a large quantity of power in a reliable manner to vital loads that are located within. A transmission network supplying such an important area must have a high standard of reliability. Therefore, those transmission systems require a special form of redundancy in order to prevent sustained outages after severe contingencies such as multiple faults. This paper outlines different forms of redundancy, and the fundamental options for designing a metropolitan network based on different forms of redundancy are illustrated. Relative merits and drawbacks of network designs based on each form of redundancy are also shown.展开更多
Bacterial biofilms,especially those caused by multidrug-resistant bacteria,have emerged as one of the greatest dangers to global public health.The acceleration of antimicrobial resistance to conventional an-tibiotics ...Bacterial biofilms,especially those caused by multidrug-resistant bacteria,have emerged as one of the greatest dangers to global public health.The acceleration of antimicrobial resistance to conventional an-tibiotics and the severe lack of new drugs necessitates the development of novel agents for biofilm eradication.Photodynamic therapy(PDT)is a promising non-antibiotic method for treating bacterial infections.However,its application in biofilm eradication is hampered by the hypoxic microenvironment of biofilms and the physical protection of extracellular polymeric substances.In this study,we develop a composite nanoplatform with oxygen(O_(2))self-supplying and heat-sensitizing capabilities to improve the PDT efficacy against biofilms.CaO_(2)/ICG@PDA nanoparticles(CIP NPs)are fabricated by combining calcium peroxide(CaO_(2))with the photosensitizer indocyanine green(ICG)via electrostatic interactions,followed by coating with polydopamine(PDA).The CIP NPs can gradually generate O_(2)in response to the acidic microenvironment of the biofilm,thereby alleviating its hypoxic state.Under near-infrared(NIR)irradiation,the nanoplatform converts O_(2)into a significant amount of singlet oxygen(^(1)O_(2))and heat to eradicate biofilm.The generated heat enhances the release of O_(2),accelerates the generation of^(1)O_(2)in PDT,increases cell membrane permeability,and increases bacterial sensitivity to^(1)O_(2).This nanoplatform significantly improves the efficacy of PDT in eradicating biofilm-dwelling bacteria without fostering drug resistance.Experiments on biofilm eradication demonstrate that this nanoplatform can eradicate over 99.9999%of methicillin-resistant Staphylococcus aureus(MRSA)biofilms under 5-min NIR irradiation.Notably,these integrated advantages enable the system to promote the healing of MRSA biofilm-infected wounds with negligible toxicity in vivo,indicating great promise for overcoming the obstacles associated with bacterial biofilm eradication.展开更多
Traction power systems(TPSs)play a vital role in the operation of electrified railways.The transformation of conventional railway TPSs to novel structures is not only a trend to promote the development of electrified ...Traction power systems(TPSs)play a vital role in the operation of electrified railways.The transformation of conventional railway TPSs to novel structures is not only a trend to promote the development of electrified railways toward high-efficiency and resilience but also an inevitable requirement to achieve carbon neutrality target.On the basis of sorting out the power supply structures of conventional AC and DC modes,this paper first reviews the characteristics of the existing TPSs,such as weak power supply flexibility and low-energy efficiency.Furthermore,the power supply structures of various TPSs for future electrified railways are described in detail,which satisfy longer distance,low-carbon,high-efficiency,high-reliability and high-quality power supply requirements.Meanwhile,the application prospects of different traction modes are discussed from both technical and economic aspects.Eventually,this paper introduces the research progress of mixed-system electrified railways and traction power supply technologies without catenary system,speculates on the future development trends and challenges of TPSs and predicts that TPSs will be based on the continuous power supply mode,employing power electronic equipment and intelligent information technology to construct a railway comprehensive energy system with renewable energy.展开更多
Losses due to hazards are inevitable and numerical simulations for estimations are complex.This study proposes a model for estimating correlated seismic damages and losses of a water supply pipeline system as an alter...Losses due to hazards are inevitable and numerical simulations for estimations are complex.This study proposes a model for estimating correlated seismic damages and losses of a water supply pipeline system as an alternative for numerical simulations.The common approach in other research shows average damage spots per mesh estimated statistically independent to one another.Spatially distributed lifeline systems,such as water supply pipelines,are interconnected,and seismic spatial variability affects the damages across the region;thus,spatial correlation of damage spots is an important factor in target areas for portfolio loss estimation.Generally,simulations are used to estimate possible losses;however,these assume each damage behaves independently and uncorrelated.This paper assumed that damages per mesh behave in a Poisson distribution to avoid over-dispersion and eliminate negative losses in estimations.The purpose of this study is to obtain a probabilistic portfolio loss model of an extensive water supply area.The proposed model was compared to the numerical simulation data with the correlated Poisson distribution.The application of the Normal To Anything(NORTA)obtained correlations for Poisson Distributions.The proposed probabilistic portfolio loss model,based on the generalized linear model and central limit theory,estimated the possible losses,such as the Probable Maximum Loss(PML,90%non-exceedance)or Normal Expected Loss(NEL,50%non-exceedance).The proposed model can be used in other lifeline systems as well,though additional investigation is needed for confirmation.From the estimations,a seismic physical portfolio loss for the water supply system was presented.The portfolio was made to show possible outcomes for the system.The proposed method was tested and analyzed using an artificial field and a location-based scenario of a water supply pipeline system.This would aid in pre-disaster planning and would require only a few steps and time.展开更多
A circular and sustainable economy for the private transport sector requires a holistic view of the emitted CO_(2) emissions.Looking at the energy supplied to the vehicle in terms of a circular economy leads to defoss...A circular and sustainable economy for the private transport sector requires a holistic view of the emitted CO_(2) emissions.Looking at the energy supplied to the vehicle in terms of a circular economy leads to defossilisation.The remaining energy sources or forms are renewable electric energy,green hydrogen and renewable fuels.A holistic view of the CO_(2) emissions of these energy sources and forms and the resulting powertrain technologies must take into account all cradle-to-grave emissions for both the vehicle and the energy supply.In order to compare the different forms of energy,the three most relevant forms of powertrain technology are considered and a configuration is chosen that allows for an appropriate comparison.For this purpose,data from the FVV project“Powertrain 2040”are used[1]and combined with research data on the energy supply chain for passenger cars.The three comparable powertrain configurations are a battery electric vehicle,a fuel cell electric vehicle and an internal combustion engine hybrid vehicle fueled with electric fuel.First,the three selected powertrain configurations are presented in terms of their performance,weight,technology and other characteristics.A comparative analysis is carried out for different CO_(2) emissions of the electricity mix.The electricity mix is used for both the production of the vehicle and the energy.The results are presented in the form of cradle-to-wheel emissions,which consider the total CO_(2) emissions of the vehicle over its life cycle.Finally,the results are analyzed and discussed to determine which powertrain technology fits best into which energy sector CO_(2) emissions window.展开更多
The cement mortar lining(CML)of commonly used ductile iron pipes can severely deteriorate the drinking water quality at the initial stage of use,but the behavioral characteristics of different elements release from th...The cement mortar lining(CML)of commonly used ductile iron pipes can severely deteriorate the drinking water quality at the initial stage of use,but the behavioral characteristics of different elements release from the CML in this stage is still unclear.In this study,dynamic immersion experiments with new cement mortar lined ductile iron pipe reactors were conducted under different feed water hardness and alkalinity conditions.The results showed that the release of alkaline substances from the CML at the initial stage of use could strongly influence the pH of water,which consequently greatly impacted the release/precipitation behaviors of calcium,aluminum and silicon.The pH and aluminum concentration of the effluent water could reach 11.5 and 700μg/L within 24 hr of hydraulic retention time,respectively,under conditions of relatively lower hardness and alkalinity.Due to the pH elevation,calcium carbonate precipitation could occur even at much lower feed water alkalinity.Whereas the aluminum and silicon could keep release from the CML in soluble form at different hardness and alkalinity levels,and their release rate depended on the amount of calcium carbonate precipitation.Thus,aluminum and silicon were more suitable as indicators of the corrosion intensity at the initial stage of CML use rather than the traditional calcium carbonate precipitation potential.Appropriate feed water hardness and alkalinity levels for mitigating the initial intense corrosion of CML were proposed:hardness>40 mg/L(CaCO_(3)),alkalinity>100 mg/L(CaCO_(3)).展开更多
The low-frequency oscillation(LFO)has occurred in the train-network system due to the introduction of the power electronics of the trains.The modeling and analyzing method in current researches based on electrified ra...The low-frequency oscillation(LFO)has occurred in the train-network system due to the introduction of the power electronics of the trains.The modeling and analyzing method in current researches based on electrified railway unilateral power supply system are not suitable for the LFO analysis in a bilateral power supply system,where the trains are supplied by two traction substations.In this work,based on the single-input and single-output impedance model of China CRH5 trains,the node admittance matrices of the train-network system both in unilateral and bilateral power supply modes are established,including three-phase power grid,traction transformers and traction network.Then the modal analysis is used to study the oscillation modes and propagation characteristics of the unilateral and bilateral power supply systems.Moreover,the influence of the equivalent inductance of the power grid,the length of the transmission line,and the length of the traction network are analyzed on the critical oscillation mode of the bilateral power supply system.Finally,the theoretical analysis results are verified by the time-domain simulation model in MATLAB/Simulink.展开更多
This paper proposes a longitudinal protection scheme utilizing empirical wavelet transform(EWT)for a through-type cophase traction direct power supply system,where both sides of a traction network line exhibit a disti...This paper proposes a longitudinal protection scheme utilizing empirical wavelet transform(EWT)for a through-type cophase traction direct power supply system,where both sides of a traction network line exhibit a distinctive boundary structure.This approach capitalizes on the boundary’s capacity to attenuate the high-frequency component of fault signals,resulting in a variation in the high-frequency transient energy ratio when faults occur inside or outside the line.During internal line faults,the high-frequency transient energy at the checkpoints located at both ends surpasses that of its neighboring lines.Conversely,for faults external to the line,the energy is lower compared to adjacent lines.EWT is employed to decompose the collected fault current signals,allowing access to the high-frequency transient energy.The longitudinal protection for the traction network line is established based on disparities between both ends of the traction network line and the high-frequency transient energy on either side of the boundary.Moreover,simulation verification through experimental results demonstrates the effectiveness of the proposed protection scheme across various initial fault angles,distances to faults,and fault transition resistances.展开更多
This study conducts a systematic literature review(SLR)of blockchain consensus mechanisms,an essential protocols that maintain the integrity,reliability,and decentralization of distributed ledger networks.The aim is t...This study conducts a systematic literature review(SLR)of blockchain consensus mechanisms,an essential protocols that maintain the integrity,reliability,and decentralization of distributed ledger networks.The aim is to comprehensively investigate prominent mechanisms’security features and vulnerabilities,emphasizing their security considerations,applications,challenges,and future directions.The existing literature offers valuable insights into various consensus mechanisms’strengths,limitations,and security vulnerabilities and their real-world applications.However,there remains a gap in synthesizing and analyzing this knowledge systematically.Addressing this gap would facilitate a structured approach to understanding consensus mechanisms’security and vulnerabilities comprehensively.The study adheres to Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines and computer science standards and reviewed 3749 research papers from 2016 to 2024,excluding grey literature,resulting in 290 articles for descriptive analysis.The research highlights an increased focus on blockchain consensus security,energy efficiency,and hybrid mechanisms within 60%of research papers post-2019,identifying gaps in scalability,privacy,and interoperability for future exploration.By synthesizing the existing research and identifying the key trends,this SLR contributes to advancing the understanding of blockchain consensus mechanisms’security and guiding future research and structured innovation in blockchain systems and applications.展开更多
Blockchain technology has attracted worldwide atten-tion,and has strong application potential in complex product system supply chain and other fields.This paper focuses on the supply chain management issues of complex...Blockchain technology has attracted worldwide atten-tion,and has strong application potential in complex product system supply chain and other fields.This paper focuses on the supply chain management issues of complex product systems,and combines the technical characteristics of blockchain,such as tamper resistance and strong resistance to destruction,to conduct research on the application of blockchain based supply chain management for complex product systems.The block-chain technology is integrated into functional modules such as business interaction,privacy protection,data storage,and sys-tem services.The application technology architecture of com-plex product system supply chain integrated with blockchain is constructed.The application practice in complex product sys-tem supply chain is carried out.The results show that the sup-ply chain of complex product systems has the functions of traceability,cost reduction,and anti-counterfeiting protection.Finally,the future development direction and research focus of the complex product system supply chain based on blockchain are prospected,which provides a reference for the equipment manufacturing supply chain management in the mili-tary industry.展开更多
Heat engines based on reciprocating machines remain in demand as energy converters in a variety of industries around the world.The aim of the study was to evaluate the gas-dynamic,consumable and heat exchange characte...Heat engines based on reciprocating machines remain in demand as energy converters in a variety of industries around the world.The aim of the study was to evaluate the gas-dynamic,consumable and heat exchange characteristics of non-stationary air flows in a supply system with transverse profiling of valve channels based on experimental studies.Valve channels with cross sections in the form of a circle,square and triangle were used to control the consumable and heat exchange characteristics of the flows in the supply system of the reciprocatingengine model.The article presents data on changes in local velocity,volumetric airflow and instantaneous heat transfer coefficient of non-stationary airflow in supply systems with different valve channel designs.A spectral analysis of the pulsations of the local heat transfer coefficient was also performed.The Nusselt number was calculated for the studied supply systems.The figured valve channels lead to an increase in the volumetric airflow through the supply systemupto32%comparedwiththe basic configuration.The useof a square valve channel leads to suppression of heat transfer(drop is about 15%)compared to the basic supply system,and the use of a triangular valve channel causes an intensification of heat transfer(growth is about 17.5%).The obtained data can be useful for refining mathematical models,adjusting machine learning algorithms,and improving design methods for supply systems of reciprocating machines to improve their technical,economic,and environmental characteristics.展开更多
文摘In current China, the main problem existing in the rural public goods supplying system is the unbalanced condition of public goods supply, and the chief reason for which is unitary system of supply main body. Thus the leading countermeasure for comer of public goods supply is to reform the present unitary rural public goods supplying system, to strengthen functional transfer of rural grass-roots directive organization, to adopt diversified mode and provide public goods on the base of overall planning of urban and rural areas and to implement unitary and diversified supplying strategy. In this way, supplying efficiency of the rural public goods will be improved.
文摘Background: The availability of essential medicines and medical supplies is crucial for effectively delivering healthcare services. In Zambia, the Logistics Management Information System (LMIS) is a key tool for managing the supply chain of these commodities. This study aimed to evaluate the effectiveness of LMIS in ensuring the availability of essential medicines and medical supplies in public hospitals in the Copperbelt Province of Zambia. Materials and Methods: From February to April 2022, a cross-sectional study was conducted in 12 public hospitals across the Copperbelt Province. Data were collected using structured questionnaires, checklists, and stock control cards. The study assessed LMIS availability, training, and knowledge among pharmacy personnel, as well as data accuracy, product availability, and order fill rates. Descriptive statistics were used to analyse the data. Results: All surveyed hospitals had LMIS implemented and were using eLMIS as the primary LMIS. Only 47% and 48% of pharmacy personnel received training in eLMIS and Essential Medicines Logistics Improvement Program (EMLIP), respectively. Most personnel demonstrated good knowledge of LMIS, with 77.7% able to log in to eLMIS Facility Edition, 76.6% able to locate stock control cards in the system, and 78.7% able to perform transactions. However, data accuracy from physical and electronic records varied from 0% to 60%, and product availability ranged from 50% to 80%. Order fill rates from Zambia Medicines and Medical Supplies Agency (ZAMMSA) were consistently below 30%. Discrepancies were observed between physical stock counts and eLMIS records. Conclusion: This study found that most hospitals in the Copperbelt Province of Zambia have implemented LMIS use. While LMIS implementation is high in the Copperbelt Province of Zambia, challenges such as low training levels, data inaccuracies, low product availability, and order fill rates persist. Addressing these issues requires a comprehensive approach, including capacity building, data quality improvement, supply chain coordination, and investment in infrastructure and human resources. Strengthening LMIS effectiveness is crucial for improving healthcare delivery and patient outcomes in Zambia.
文摘For any country,the availability of electricity is crucial to the development of the national economy and society.As a result,decision-makers and policy-makers can improve the sustainability and security of the energy supply by implementing a variety of actions by using the evaluation of these factors as an early warning system.This research aims to provide a multi-criterion decision-making(MCDM)method for assessing the sustainability and security of the electrical supply.The weights of criteria,which indicate their relative relevance in the assessment of the sustainability and security of the energy supply,the MCDM method allow users to express their opinions.To overcome the impact of uncertainty and vagueness of expert opinion,we explore the notion of picture fuzzy theory,which is a more efficient and dominant mathematical model.Recently,the theory of Aczel-Alsina operations has attained a lot of attraction and has an extensive capability to acquire smooth approximated results during the aggregation process.However,Choquet integral operators are more flexible and are used to express correlation among different attributes.This article diagnoses an innovative theory of picture fuzzy set to derive robust mathematical methodologies of picture fuzzy Choquet Integral Aczel-Alsina aggregation operators.To prove the intensity and validity of invented approaches,some dominant properties and special cases are also discussed.An intelligent decision algorithm for the MCDM problem is designed to resolve complicated real-life applications under multiple conflicting criteria.Additionally,we discussed a numerical example to investigate a suitable electric transformer under consideration of different beneficial key criteria.A comparative study is established to capture the superiority and effectiveness of pioneered mathematical approaches with existing methodologies.
文摘Rice straw,a by-product of rice cultivation,is commonly disposed of through open-field burning,which contributes to air pollution and environmental degradation.This study aims to identify the key factors influencing farmers’decisions on rice straw management and to develop policy recommendations that encourage the sustainable utilization of rice straw within the supply chain.A mixed-methods approach was adopted,combining qualitative interviews with nine key informants and a quantitative survey of 585 rice farmers across Thailand.Multinomial Logit Regression(MLR)was employed to analyze farmers’preferences among four management options:burning,composting,animal feeding,and selling.The results reveal that membership in farmer groups,ownership of livestock,access to baling machinery,knowledge,and skills related to straw utilization,ease of field access,availability of storage facilities,engagement in integrated farming,and year-round access to baling services significantly increased the likelihood of choosing sustainable alternatives over the burning straw.These findings underscore the importance of both capacity-building and infrastructure in enabling sustainable practices.Based on these insights,the study proposes a multi-level policy framework to enhance the value creation of rice straw.National policies should focus on expanding access to machinery and supporting innovation,while local governments should facilitate farmer training and improve straw logistics.Strengthening farmer organizations and market connections is also crucial for scaling adoption.Overall,structural integration and stakeholder coordination are key to reducing straw burning and promoting sustainable resource use in rice-producing regions.
基金Trafikföorvaltningen Region Stockholm and Trafikverket for funding and supporting this study.
文摘Purpose–Adding an appropriate pre-sag to the geometry of simple catenary systems for electric railways can improve their performance in dynamic interaction with the pantographs of trains operating under them.The value of pre-sag can be obtained by empirical approximation or computationally expensive optimisation.This study aims to define a simple but accurate method to determine a suitable pre-sag without dynamic simulations and to find its limitations.Design/methodology/approach–A quasi-static method to determine the ideal value of pre-sag is described based on elasticity variations.It considers variations of the static contact force.The limits of this method are investigated by comparing it to a parametric dynamic simulation study.In the dynamic simulation,an optimal level of pre-sag is identified for each contact force level.The influence of the speed in the dynamic simulation results is expressed in two parameters:the quasi-static influence in the mean contact force and the dynamic influence in the ratio between the vehicle speed and the wave propagation speed in the contact wire.Findings–The comparison between the suggested method and the dynamic simulations shows a high consistency up to a speed limit of around 40%of the wave propagation speed.The best agreement with the dynamic results is achieved by calculating the optimal pre-sag based on the absolute elasticity variation.Practical implications–The simplified approach for determining the pre-sag is valid for low-speed applications,such as suburban railway lines.For these cases,a highly suitable geometry can be obtained with the suggested method,meaning a significantly reduced computational effort.As a case study for this work,the results are applied to a Swedish suburban rail line upgrade case.Originality/value–The static uplift force is added as a varied parameter in dynamic simulations.The shift in system behaviour from low to high dynamics is described,and how the benefits from pre-sag are visible and then disappear.The limit value of the low-dynamics regime is identified to be 40%.
基金supported by the National Natural Science Foundation of China(No.52107125)Applied Basic Research Project of Sichuan Province(No.2022NSFSC0250)Chengdu Guojia Electrical Engineering Co.,Ltd.(No.KYL202312-0043).
文摘Critical for metering and protection in electric railway traction power supply systems(TPSSs),the measurement performance of voltage transformers(VTs)must be timely and reliably monitored.This paper outlines a three-step,RMS data only method for evaluating VTs in TPSSs.First,a kernel principal component analysis approach is used to diagnose the VT exhibiting significant measurement deviations over time,mitigating the influence of stochastic fluctuations in traction loads.Second,a back propagation neural network is employed to continuously estimate the measurement deviations of the targeted VT.Third,a trend analysis method is developed to assess the evolution of the measurement performance of VTs.Case studies conducted on field data from an operational TPSS demonstrate the effectiveness of the proposed method in detecting VTs with measurement deviations exceeding 1%relative to their original accuracy levels.Additionally,the method accurately tracks deviation trends,enabling the identification of potential early-stage faults in VTs and helping prevent significant economic losses in TPSS operations.
基金Gansu Provincial Department of Education(Industrial Support Plan Project:202CYZC-048).
文摘Hydraulic control valves, positioned at the terminus of pipe networks, are critical for regulatingflow and pressure, thereby ensuring the operational safety and efficiency of pipeline systems. However,conventional valve designs often struggle to maintain effective regulation across a wide range of systempressures. To address this limitation, this study introduces a novel Pilot hydraulic valves specificallyengineered for enhanced dynamic performance and precise regulation under variable pressure conditions.Building upon prior experimental findings, the proposed design integrates a high-fidelity simulationframework and a surrogate model-based optimization strategy. The study begins by formulating acomprehensive mathematical model of the pipeline system using electro-hydraulic simulation techniques,capturing the dynamic behavior of both the pilot valve and the broader urban water distribution network. Acoupled simulation platform is then developed, leveraging both one-dimensional (1D) and three-dimensional(3D) software tools to accurately analyze the valve’s transient response and operational characteristics. Toachieve optimal valve performance, a multi-objective optimization approach is proposed. This approachemploys a Levy-based Improved Tuna-InspiredWake-Up Optimization Algorithm (L-TIWOA) to refine aBackpropagation (BP) neural network, thereby constructing a highly accurate surrogate model. Compared tothe conventional BP neural network, the improved model demonstrates significantly reduced mean absoluteerror (MAE) and mean squared error (MSE), underscoring its superior predictive capability. The surrogatemodel serves as the objective function within an Improved Multi-Objective Mother Lode OptimizationAlgorithm (IMOMLOA), which is then used to fine-tune the key design parameters of the control valve.Validation through experimental testing reveals that the optimized valve achieves a maximum flow deviationof just 1.11 t/h, corresponding to a control accuracy of 3.7%, at a target flow rate of 30 t/h. Moreover,substantial improvements in dynamic response are observed, confirming the effectiveness of the proposeddesign and optimization strategy.
文摘This article focuses on the optimization of water supply and drainage systems,involving theories such as hydraulic models of pipeline systems and multi-objective collaborative optimization.It introduces the system dynamics model of sewage treatment facility expansion.Elaborating on detection technology,construction of an intelligent operation and maintenance system,and factors to be considered for sewage plant expansion,it emphasizes the importance of collaborative development and verifies benefits through the PSR model.
基金supported by the National Natural Science Foundation of China(Grant No.51806234)。
文摘The liquid nitrogen(LN2)supplying system,one of the four key systems of the cryogenic wind tunnel(CWT),is an essential guarantee for the precise control,fast and safe regulation of the wind tunnel’s total temperature.Firstly,the technical schemes,advantages and disadvantages of different LN2 supplying systems are discussed and analyzed based on the operation conditions and test requirements of different CWTs.Then,together with the development of the pilot cryogenic transonic wind tunnel(PCTW),the key technologies of the system,including the supplying mode,rapid and accurate regulation of injection pressure,development of large scale cryogenic centrifugal pump,and matching technology between pumps and pipe network,have been summarized and the solutions to the existing issues are given.Finally,a supplying process suitable for large-scale CWT is proposed,which has the ability of independent commissioning,rapid regulation,accurate control of injection pressure and transient response to the wind tunnel’s wide range of working conditions.The breakthrough in LN2 supplying system enables China to construct a CWT for the future competitive high Reynolds number aircraft.
文摘Transgression networks in metropolitan centers need to supply a large quantity of power in a reliable manner to vital loads that are located within. A transmission network supplying such an important area must have a high standard of reliability. Therefore, those transmission systems require a special form of redundancy in order to prevent sustained outages after severe contingencies such as multiple faults. This paper outlines different forms of redundancy, and the fundamental options for designing a metropolitan network based on different forms of redundancy are illustrated. Relative merits and drawbacks of network designs based on each form of redundancy are also shown.
基金supported by the National Natural Science Foundation of China(No.22175125)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.21KJA150008)the Key Laboratory of Polymeric Materials De-sign and Synthesis for Biomedical Function,Soochow University,and the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Bacterial biofilms,especially those caused by multidrug-resistant bacteria,have emerged as one of the greatest dangers to global public health.The acceleration of antimicrobial resistance to conventional an-tibiotics and the severe lack of new drugs necessitates the development of novel agents for biofilm eradication.Photodynamic therapy(PDT)is a promising non-antibiotic method for treating bacterial infections.However,its application in biofilm eradication is hampered by the hypoxic microenvironment of biofilms and the physical protection of extracellular polymeric substances.In this study,we develop a composite nanoplatform with oxygen(O_(2))self-supplying and heat-sensitizing capabilities to improve the PDT efficacy against biofilms.CaO_(2)/ICG@PDA nanoparticles(CIP NPs)are fabricated by combining calcium peroxide(CaO_(2))with the photosensitizer indocyanine green(ICG)via electrostatic interactions,followed by coating with polydopamine(PDA).The CIP NPs can gradually generate O_(2)in response to the acidic microenvironment of the biofilm,thereby alleviating its hypoxic state.Under near-infrared(NIR)irradiation,the nanoplatform converts O_(2)into a significant amount of singlet oxygen(^(1)O_(2))and heat to eradicate biofilm.The generated heat enhances the release of O_(2),accelerates the generation of^(1)O_(2)in PDT,increases cell membrane permeability,and increases bacterial sensitivity to^(1)O_(2).This nanoplatform significantly improves the efficacy of PDT in eradicating biofilm-dwelling bacteria without fostering drug resistance.Experiments on biofilm eradication demonstrate that this nanoplatform can eradicate over 99.9999%of methicillin-resistant Staphylococcus aureus(MRSA)biofilms under 5-min NIR irradiation.Notably,these integrated advantages enable the system to promote the healing of MRSA biofilm-infected wounds with negligible toxicity in vivo,indicating great promise for overcoming the obstacles associated with bacterial biofilm eradication.
基金supported in part by the Scientific Foundation for Outstanding Young Scientists of Sichuan under Grant No.2021JDJQ0032in part by the National Natural Science Foundation of China under Grant No.52107128in part by the Natural Science Foundation of Sichuan Province under Grant No.2022NSFSC0436.
文摘Traction power systems(TPSs)play a vital role in the operation of electrified railways.The transformation of conventional railway TPSs to novel structures is not only a trend to promote the development of electrified railways toward high-efficiency and resilience but also an inevitable requirement to achieve carbon neutrality target.On the basis of sorting out the power supply structures of conventional AC and DC modes,this paper first reviews the characteristics of the existing TPSs,such as weak power supply flexibility and low-energy efficiency.Furthermore,the power supply structures of various TPSs for future electrified railways are described in detail,which satisfy longer distance,low-carbon,high-efficiency,high-reliability and high-quality power supply requirements.Meanwhile,the application prospects of different traction modes are discussed from both technical and economic aspects.Eventually,this paper introduces the research progress of mixed-system electrified railways and traction power supply technologies without catenary system,speculates on the future development trends and challenges of TPSs and predicts that TPSs will be based on the continuous power supply mode,employing power electronic equipment and intelligent information technology to construct a railway comprehensive energy system with renewable energy.
文摘Losses due to hazards are inevitable and numerical simulations for estimations are complex.This study proposes a model for estimating correlated seismic damages and losses of a water supply pipeline system as an alternative for numerical simulations.The common approach in other research shows average damage spots per mesh estimated statistically independent to one another.Spatially distributed lifeline systems,such as water supply pipelines,are interconnected,and seismic spatial variability affects the damages across the region;thus,spatial correlation of damage spots is an important factor in target areas for portfolio loss estimation.Generally,simulations are used to estimate possible losses;however,these assume each damage behaves independently and uncorrelated.This paper assumed that damages per mesh behave in a Poisson distribution to avoid over-dispersion and eliminate negative losses in estimations.The purpose of this study is to obtain a probabilistic portfolio loss model of an extensive water supply area.The proposed model was compared to the numerical simulation data with the correlated Poisson distribution.The application of the Normal To Anything(NORTA)obtained correlations for Poisson Distributions.The proposed probabilistic portfolio loss model,based on the generalized linear model and central limit theory,estimated the possible losses,such as the Probable Maximum Loss(PML,90%non-exceedance)or Normal Expected Loss(NEL,50%non-exceedance).The proposed model can be used in other lifeline systems as well,though additional investigation is needed for confirmation.From the estimations,a seismic physical portfolio loss for the water supply system was presented.The portfolio was made to show possible outcomes for the system.The proposed method was tested and analyzed using an artificial field and a location-based scenario of a water supply pipeline system.This would aid in pre-disaster planning and would require only a few steps and time.
文摘A circular and sustainable economy for the private transport sector requires a holistic view of the emitted CO_(2) emissions.Looking at the energy supplied to the vehicle in terms of a circular economy leads to defossilisation.The remaining energy sources or forms are renewable electric energy,green hydrogen and renewable fuels.A holistic view of the CO_(2) emissions of these energy sources and forms and the resulting powertrain technologies must take into account all cradle-to-grave emissions for both the vehicle and the energy supply.In order to compare the different forms of energy,the three most relevant forms of powertrain technology are considered and a configuration is chosen that allows for an appropriate comparison.For this purpose,data from the FVV project“Powertrain 2040”are used[1]and combined with research data on the energy supply chain for passenger cars.The three comparable powertrain configurations are a battery electric vehicle,a fuel cell electric vehicle and an internal combustion engine hybrid vehicle fueled with electric fuel.First,the three selected powertrain configurations are presented in terms of their performance,weight,technology and other characteristics.A comparative analysis is carried out for different CO_(2) emissions of the electricity mix.The electricity mix is used for both the production of the vehicle and the energy.The results are presented in the form of cradle-to-wheel emissions,which consider the total CO_(2) emissions of the vehicle over its life cycle.Finally,the results are analyzed and discussed to determine which powertrain technology fits best into which energy sector CO_(2) emissions window.
基金supported by the Beijing Municipal Science&Technology Program (No.Z201100008220003)the National Key R&D Program of China (No.2019YFD1100105)。
文摘The cement mortar lining(CML)of commonly used ductile iron pipes can severely deteriorate the drinking water quality at the initial stage of use,but the behavioral characteristics of different elements release from the CML in this stage is still unclear.In this study,dynamic immersion experiments with new cement mortar lined ductile iron pipe reactors were conducted under different feed water hardness and alkalinity conditions.The results showed that the release of alkaline substances from the CML at the initial stage of use could strongly influence the pH of water,which consequently greatly impacted the release/precipitation behaviors of calcium,aluminum and silicon.The pH and aluminum concentration of the effluent water could reach 11.5 and 700μg/L within 24 hr of hydraulic retention time,respectively,under conditions of relatively lower hardness and alkalinity.Due to the pH elevation,calcium carbonate precipitation could occur even at much lower feed water alkalinity.Whereas the aluminum and silicon could keep release from the CML in soluble form at different hardness and alkalinity levels,and their release rate depended on the amount of calcium carbonate precipitation.Thus,aluminum and silicon were more suitable as indicators of the corrosion intensity at the initial stage of CML use rather than the traditional calcium carbonate precipitation potential.Appropriate feed water hardness and alkalinity levels for mitigating the initial intense corrosion of CML were proposed:hardness>40 mg/L(CaCO_(3)),alkalinity>100 mg/L(CaCO_(3)).
基金This work was supported by the Applied Basic Research Program of Science and Technology Plan Project of Sichuan Province of China(No.2020YJ0252).
文摘The low-frequency oscillation(LFO)has occurred in the train-network system due to the introduction of the power electronics of the trains.The modeling and analyzing method in current researches based on electrified railway unilateral power supply system are not suitable for the LFO analysis in a bilateral power supply system,where the trains are supplied by two traction substations.In this work,based on the single-input and single-output impedance model of China CRH5 trains,the node admittance matrices of the train-network system both in unilateral and bilateral power supply modes are established,including three-phase power grid,traction transformers and traction network.Then the modal analysis is used to study the oscillation modes and propagation characteristics of the unilateral and bilateral power supply systems.Moreover,the influence of the equivalent inductance of the power grid,the length of the transmission line,and the length of the traction network are analyzed on the critical oscillation mode of the bilateral power supply system.Finally,the theoretical analysis results are verified by the time-domain simulation model in MATLAB/Simulink.
基金supported by the National Natural Science Foundation of China(51767012)Curriculum Ideological and Political Connotation Construction Project of Kunming University of Science and Technology(2021KS009)Kunming University of Science and Technology Online Open Course(MOOC)Construction Project(202107).
文摘This paper proposes a longitudinal protection scheme utilizing empirical wavelet transform(EWT)for a through-type cophase traction direct power supply system,where both sides of a traction network line exhibit a distinctive boundary structure.This approach capitalizes on the boundary’s capacity to attenuate the high-frequency component of fault signals,resulting in a variation in the high-frequency transient energy ratio when faults occur inside or outside the line.During internal line faults,the high-frequency transient energy at the checkpoints located at both ends surpasses that of its neighboring lines.Conversely,for faults external to the line,the energy is lower compared to adjacent lines.EWT is employed to decompose the collected fault current signals,allowing access to the high-frequency transient energy.The longitudinal protection for the traction network line is established based on disparities between both ends of the traction network line and the high-frequency transient energy on either side of the boundary.Moreover,simulation verification through experimental results demonstrates the effectiveness of the proposed protection scheme across various initial fault angles,distances to faults,and fault transition resistances.
基金funded by Universiti Teknologi PETRONAS and grants(YUTP-PRG:015PBC-011).
文摘This study conducts a systematic literature review(SLR)of blockchain consensus mechanisms,an essential protocols that maintain the integrity,reliability,and decentralization of distributed ledger networks.The aim is to comprehensively investigate prominent mechanisms’security features and vulnerabilities,emphasizing their security considerations,applications,challenges,and future directions.The existing literature offers valuable insights into various consensus mechanisms’strengths,limitations,and security vulnerabilities and their real-world applications.However,there remains a gap in synthesizing and analyzing this knowledge systematically.Addressing this gap would facilitate a structured approach to understanding consensus mechanisms’security and vulnerabilities comprehensively.The study adheres to Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines and computer science standards and reviewed 3749 research papers from 2016 to 2024,excluding grey literature,resulting in 290 articles for descriptive analysis.The research highlights an increased focus on blockchain consensus security,energy efficiency,and hybrid mechanisms within 60%of research papers post-2019,identifying gaps in scalability,privacy,and interoperability for future exploration.By synthesizing the existing research and identifying the key trends,this SLR contributes to advancing the understanding of blockchain consensus mechanisms’security and guiding future research and structured innovation in blockchain systems and applications.
基金supported by the National Natural Science Foundation of China(71871007)Project of Chinese Academy of Engineering.
文摘Blockchain technology has attracted worldwide atten-tion,and has strong application potential in complex product system supply chain and other fields.This paper focuses on the supply chain management issues of complex product systems,and combines the technical characteristics of blockchain,such as tamper resistance and strong resistance to destruction,to conduct research on the application of blockchain based supply chain management for complex product systems.The block-chain technology is integrated into functional modules such as business interaction,privacy protection,data storage,and sys-tem services.The application technology architecture of com-plex product system supply chain integrated with blockchain is constructed.The application practice in complex product sys-tem supply chain is carried out.The results show that the sup-ply chain of complex product systems has the functions of traceability,cost reduction,and anti-counterfeiting protection.Finally,the future development direction and research focus of the complex product system supply chain based on blockchain are prospected,which provides a reference for the equipment manufacturing supply chain management in the mili-tary industry.
基金supported by the Russian Science Foundation(Grant No.23-29-00022).
文摘Heat engines based on reciprocating machines remain in demand as energy converters in a variety of industries around the world.The aim of the study was to evaluate the gas-dynamic,consumable and heat exchange characteristics of non-stationary air flows in a supply system with transverse profiling of valve channels based on experimental studies.Valve channels with cross sections in the form of a circle,square and triangle were used to control the consumable and heat exchange characteristics of the flows in the supply system of the reciprocatingengine model.The article presents data on changes in local velocity,volumetric airflow and instantaneous heat transfer coefficient of non-stationary airflow in supply systems with different valve channel designs.A spectral analysis of the pulsations of the local heat transfer coefficient was also performed.The Nusselt number was calculated for the studied supply systems.The figured valve channels lead to an increase in the volumetric airflow through the supply systemupto32%comparedwiththe basic configuration.The useof a square valve channel leads to suppression of heat transfer(drop is about 15%)compared to the basic supply system,and the use of a triangular valve channel causes an intensification of heat transfer(growth is about 17.5%).The obtained data can be useful for refining mathematical models,adjusting machine learning algorithms,and improving design methods for supply systems of reciprocating machines to improve their technical,economic,and environmental characteristics.
