This article focuses on the challenges ofmodeling energy supply systems for buildings,encompassing both methods and tools for simulating thermal regimes and engineering systems within buildings.Enhancing the comfort o...This article focuses on the challenges ofmodeling energy supply systems for buildings,encompassing both methods and tools for simulating thermal regimes and engineering systems within buildings.Enhancing the comfort of living or working in buildings often necessitates increased consumption of energy and material,such as for thermal upgrades,which consequently incurs additional economic costs.It is crucial to acknowledge that such improvements do not always lead to a decrease in total pollutant emissions,considering emissions across all stages of production and usage of energy and materials aimed at boosting energy efficiency and comfort in buildings.In addition,it explores the methods and mechanisms for modeling the operating modes of electric boilers used to collectively improve energy efficiency and indoor climatic conditions.Using the developed mathematical models,the study examines the dynamic states of building energy supply systems and provides recommendations for improving their efficiency.These dynamic models are executed in software environments such as MATLAB/Simscape and Python,where the component detailing schemes for various types of controllers are demonstrated.Additionally,controllers based on reinforcement learning(RL)displayed more adaptive load level management.These RL-based controllers can lower instantaneous power usage by up to 35%,reduce absolute deviations from a comfortable temperature nearly by half,and cut down energy consumption by approximately 1%while maintaining comfort.When the energy source produces a constant energy amount,the RL-based heat controllermore effectively maintains the temperature within the set range,preventing overheating.In conclusion,the introduced energydynamic building model and its software implementation offer a versatile tool for researchers,enabling the simulation of various energy supply systems to achieve optimal energy efficiency and indoor climate control in buildings.展开更多
In the paper,the statistical modeling method of the lightning attachment process to extended objects has been proposed.The modeling takes into account the probabilities of lightning occurrence with current of differen...In the paper,the statistical modeling method of the lightning attachment process to extended objects has been proposed.The modeling takes into account the probabilities of lightning occurrence with current of different amplitudes, and nonlinear variation of spark resistance at leader channel growth.The method also takes into consideration the dependency of velocity and acceleration of a lightning leader on its potential.The propagation of lightning channel towards the earth is tortuous and random in orientation and does not depend upon ground objects until it enters into"last stroke zone".It assumes that the lightning leader channel orientation begins when its streamer zone touches the earth,a grounded object,a grounded lightning rod or a streamer zone of the ascending leader.The probable frequency of lightning strikes to an investigated object can be obtained by the summation of the total probable number of strikes of all possible potentials at each node of the object,appearing with the assigned probability,as well as the points of origin of the heads of lightning leaders from all nodes on the plain(over the object) at corresponding heights.The proposed method is implemented to calculate the lightning stroke probability to a high voltage substation. Due to lightning attraction from the territory greater than that of the investigated object,the total number of annual probable lightning strokes to the object is increased by 1.28 times in comparison with the case of the same flat territory.展开更多
It was shown that the concentration of heavy metal ions Fe<sup>3+</sup>, Cu<sup>2+</sup>, Cr<sup>3+</sup> and Zn<sup>2+</sup>, which are contained in the fermentation me...It was shown that the concentration of heavy metal ions Fe<sup>3+</sup>, Cu<sup>2+</sup>, Cr<sup>3+</sup> and Zn<sup>2+</sup>, which are contained in the fermentation medium, affects the process of biogas production. The aim of this paper was to establish the concentration of ions, which makes it possible to increase the yield of biogas and the methane content in it. The total yield of biogas per unit of dry organic matter, methane and the kinetics of changes in the yield of biogas during fermentation of cattle manure in the presence of different concentrations of metal ions in the anaerobic environment. It was established that the content of Fe<sup>3+</sup>, Cu<sup>2+</sup> is up to 80 mg/dm<sup>3</sup>, Cr<sup>3+</sup> and Zn<sup>2+</sup> is up to 50 mg/dm<sup>3</sup> in the medium lead to increased methane production by anaerobic association of microorganisms due to the <span>effect on the activity of enzyme systems in comparison with the sample</span> without the addition of metal ions. It was found that the rational concentrations to increase the methane yield in the biogas obtained by fermentation of cattle manure are: Fe<sup>3+</sup>-20 - 40 mg/dm<sup>3</sup>, Cu<sup>2+</sup>-40 - 60 mg/dm<sup>3</sup>, Cr<sup>3+</sup>-10 mg/dm<sup>3</sup>. The increase in the concentration of metal ions above rational values leads to a decrease in the methane content in biogas. It was shown that zinc ions have a positive effect on methane production, but reduce the total biogas <span>yield and, accordingly, the degree of conversion of organic raw materials. </span>Therefore, the rational concentration of Zn<sup>2+</sup> in the fermentation medium is 10 mg/dm<sup>3</sup>.展开更多
The article presents an example of a device for focusing ultrasound through the air with the use of computer modeling technology and experimental data processing. The device is a matrix of 172 emitters operating at a ...The article presents an example of a device for focusing ultrasound through the air with the use of computer modeling technology and experimental data processing. The device is a matrix of 172 emitters operating at a frequency of 40 kHz, and the formation of the electronic unit of the ultrasound beam. Beam control on the software from your PC. Radiation pressure at the focal point was 57 Pa, and allows you to move light objects and feel the tactile effect of ultrasound. Present calculations the characteristics of the focused field and results of computer visualization of theoretical and experimental research.展开更多
We propose a framework for designing randomized stream ciphers with enhanced security. The key attribute of this framework is using of nonlinear bijective mappings or keyless hash functions for random coding. We inves...We propose a framework for designing randomized stream ciphers with enhanced security. The key attribute of this framework is using of nonlinear bijective mappings or keyless hash functions for random coding. We investigate the computational security of the proposed ciphers against chosen-plaintext-chosen-initialization-vector attacks and show that it is based on the hardness of solving some systems of random nonlinear Boolean equations. We also provide guidelines for choosing components to design randomizers for specified ciphers.展开更多
Surface of oxidized multiwalled carbon nanotubes was investigated for stabilization of nanosized tin（IV） oxide. The synthesis of nanosized tin（IV） oxide on the surface of carbon nanotubes was carried out with the ...Surface of oxidized multiwalled carbon nanotubes was investigated for stabilization of nanosized tin（IV） oxide. The synthesis of nanosized tin（IV） oxide on the surface of carbon nanotubes was carried out with the use of three soft chemical methods： sol-gel, precipitation, and thermal. The synthesized tin（IV） oxide particles on the surface of carbon nanotubes were studied by thermal analysis, X-ray diffraction and electron microscopy. The lattice parameters of tin（IV） oxide on the surface of multiwalled carbon nanotubes were calculated.展开更多
A variety of liquid thermal solar collectors designs used for water heating have been developed by the previous researchers. But the majority of them do not meet the requirements on small weight, easy assembling and i...A variety of liquid thermal solar collectors designs used for water heating have been developed by the previous researchers. But the majority of them do not meet the requirements on small weight, easy assembling and installing, versatility, scalability and adaptability of the design, which are particularly important when they are facade integrated. In order to avoid the above mentioned drawbacks of the liquid thermal collectors, the authors propose to apply to them extruded aluminum alloy made heat pipes of originally designed cross-sectional profile with wide fins and longitudinal grooves. Such solar collectors could be a good solution for building facade and roof integration, because they are assembled of several standard and independent, hermetically sealed and light-weight modules, easy mounted and ＂dry＂ connected to the main pipeline. At that, their thermal performances are not worse than of the other known ones made of heavier and more expensive copper with higher thermal conductance, or having entire rigid designs. Some variants of the developed solar collectors shaping of the assembled modules for building facade or roof integration are proposed. Variously colored coatings to the absorbers are developed and made of carbon-siliceous nano-composites by means of sol-gel method. Their optical performances were compared with ＂anodized black＂. It is stated that colored coatings have a good prospect in thermal SCs （solar collectors） adaptation to building facades decoration, but the works on study and upgrade of their performances should be continued.展开更多
The aim of the study of phase shifter on MEMS （micro-electro-mechanical systems） structures was to minimize the dimensions of the design achievement. Also, the main task was to achieve the reliability and durability...The aim of the study of phase shifter on MEMS （micro-electro-mechanical systems） structures was to minimize the dimensions of the design achievement. Also, the main task was to achieve the reliability and durability of the device. The calculation was based on the optimization technique （step by step） and the modeling of individual parts of the device, namely MEMS-keys that perform the main function--switching. The urgency of this problem is the development and study of one device as a universal, that is, automatically switches from two signals simultaneously. Designs are original and devises are the intellectual property of the authors. The program for modeling phase shifters Computer Simulation Technology Microwave Studio and its results are presented in the paper.展开更多
<strong>Background & Aim:</strong> Employees’ engagement is a significant organizational competence. Turnover intention is an institutional concern that needs critical analysis of identifying its pred...<strong>Background & Aim:</strong> Employees’ engagement is a significant organizational competence. Turnover intention is an institutional concern that needs critical analysis of identifying its predictors. Studies have supported the relationship between nurses’ engagement and their desire to leave the organization. This study aims to explore the relationship between work engagement and turnover intention among nurses working in the Kingdom of Bahrain. <strong>Methods: </strong>A cross-sectional design was used for this study. A group of 922 nurses from a major tertiary hospital in the Kingdom of Bahrain was invited to complete the online self-administered survey. The work engagement was assessed using the Utrecht Work Engagement Scale (UWES). The turnover intention was assessed using the 3-item TI Scale based on Mobley <em>et al.</em> survey. The study was conducted in December 2019. <strong>Results: </strong>610 nurses completed the survey on a response rate of (66.2%). The result suggests that nurses expressed high level of work engagement Mean ± Standard Deviation [M = 4.85, SD ± 0.70], and low level of turnover intention [M = 2.29, SD ± 0.94]. Pearson correlation revealed a significant negative relationship between work engagement and turnover intention at <em>p </em>< 0.01. Furthermore, male staff have higher intention to leave. Those working in ambulatory division have higher work engagement than nurses working in critical care division.<strong> Conclusion/practical implication:</strong> It’s paramount for the nurses’ leaders and human resource development practitioners to focus on work engagement dimensions, and developing effective interventions to improve it, which eventually decreases nursing staff’s turnover intention. Retention is more preferable than recruiting, employing, and training new staff. This study confirms the significant relationship between work engagement and turnover intention among nurses.展开更多
This paper addresses to the problem of using SAS Enterprise Guide 6.1 as a means for building probabilistic models and as optimum method of modeling gross domestic product in terms of the economic crisis and social th...This paper addresses to the problem of using SAS Enterprise Guide 6.1 as a means for building probabilistic models and as optimum method of modeling gross domestic product in terms of the economic crisis and social threats is proposed. Today in a complex socio-political and economic situation growing influence of external factors, presence of uncertainties and risks there exists a problem of anticipating potential threats in the humanitarian and social spheres and ways to overcome them aiming to provide food security and controllability of ecological situation. All these problems, as reported in the NATO program ＂Science for Peace and Security＂, are of high priority for the countries that need to take into account threats to security, including Ukraine. That is why in the framework of the project NUKR. SFPP G4877 ＂Modeling and Mitigation of Social Disasters Caused by Catastrophes and Terrorism＂ the problems of scientific prediction of national economy for the period to 2030 as one of the measures preventing growth of social tension in the country are disclosed.展开更多
There is a growing recognition of the interdependencies among the supply systems that rely upon food,water and energy.Billions of people lack safe and sufficient access to these systems,coupled with a rapidly growing ...There is a growing recognition of the interdependencies among the supply systems that rely upon food,water and energy.Billions of people lack safe and sufficient access to these systems,coupled with a rapidly growing global demand and increasing resource constraints.Modeling frameworks are considered one of the few means available to understand the complex interrelationships among the sectors,however development of nexus related frameworks has been limited.We describe three opensource models well known in their respective domains(i.e.TerrSysMP,WOFOST and SWAT)where components of each if combined could help decision-makers address the nexus issue.We propose as a first step the development of simple workflows utilizing essential variables and addressing components of the above-mentioned models which can act as building-blocks to be used ultimately in a comprehensive nexus model framework.The outputs of the workflows and the model framework are designed to address the SDGs.展开更多
文摘This article focuses on the challenges ofmodeling energy supply systems for buildings,encompassing both methods and tools for simulating thermal regimes and engineering systems within buildings.Enhancing the comfort of living or working in buildings often necessitates increased consumption of energy and material,such as for thermal upgrades,which consequently incurs additional economic costs.It is crucial to acknowledge that such improvements do not always lead to a decrease in total pollutant emissions,considering emissions across all stages of production and usage of energy and materials aimed at boosting energy efficiency and comfort in buildings.In addition,it explores the methods and mechanisms for modeling the operating modes of electric boilers used to collectively improve energy efficiency and indoor climatic conditions.Using the developed mathematical models,the study examines the dynamic states of building energy supply systems and provides recommendations for improving their efficiency.These dynamic models are executed in software environments such as MATLAB/Simscape and Python,where the component detailing schemes for various types of controllers are demonstrated.Additionally,controllers based on reinforcement learning(RL)displayed more adaptive load level management.These RL-based controllers can lower instantaneous power usage by up to 35%,reduce absolute deviations from a comfortable temperature nearly by half,and cut down energy consumption by approximately 1%while maintaining comfort.When the energy source produces a constant energy amount,the RL-based heat controllermore effectively maintains the temperature within the set range,preventing overheating.In conclusion,the introduced energydynamic building model and its software implementation offer a versatile tool for researchers,enabling the simulation of various energy supply systems to achieve optimal energy efficiency and indoor climate control in buildings.
文摘In the paper,the statistical modeling method of the lightning attachment process to extended objects has been proposed.The modeling takes into account the probabilities of lightning occurrence with current of different amplitudes, and nonlinear variation of spark resistance at leader channel growth.The method also takes into consideration the dependency of velocity and acceleration of a lightning leader on its potential.The propagation of lightning channel towards the earth is tortuous and random in orientation and does not depend upon ground objects until it enters into"last stroke zone".It assumes that the lightning leader channel orientation begins when its streamer zone touches the earth,a grounded object,a grounded lightning rod or a streamer zone of the ascending leader.The probable frequency of lightning strikes to an investigated object can be obtained by the summation of the total probable number of strikes of all possible potentials at each node of the object,appearing with the assigned probability,as well as the points of origin of the heads of lightning leaders from all nodes on the plain(over the object) at corresponding heights.The proposed method is implemented to calculate the lightning stroke probability to a high voltage substation. Due to lightning attraction from the territory greater than that of the investigated object,the total number of annual probable lightning strokes to the object is increased by 1.28 times in comparison with the case of the same flat territory.
文摘It was shown that the concentration of heavy metal ions Fe<sup>3+</sup>, Cu<sup>2+</sup>, Cr<sup>3+</sup> and Zn<sup>2+</sup>, which are contained in the fermentation medium, affects the process of biogas production. The aim of this paper was to establish the concentration of ions, which makes it possible to increase the yield of biogas and the methane content in it. The total yield of biogas per unit of dry organic matter, methane and the kinetics of changes in the yield of biogas during fermentation of cattle manure in the presence of different concentrations of metal ions in the anaerobic environment. It was established that the content of Fe<sup>3+</sup>, Cu<sup>2+</sup> is up to 80 mg/dm<sup>3</sup>, Cr<sup>3+</sup> and Zn<sup>2+</sup> is up to 50 mg/dm<sup>3</sup> in the medium lead to increased methane production by anaerobic association of microorganisms due to the <span>effect on the activity of enzyme systems in comparison with the sample</span> without the addition of metal ions. It was found that the rational concentrations to increase the methane yield in the biogas obtained by fermentation of cattle manure are: Fe<sup>3+</sup>-20 - 40 mg/dm<sup>3</sup>, Cu<sup>2+</sup>-40 - 60 mg/dm<sup>3</sup>, Cr<sup>3+</sup>-10 mg/dm<sup>3</sup>. The increase in the concentration of metal ions above rational values leads to a decrease in the methane content in biogas. It was shown that zinc ions have a positive effect on methane production, but reduce the total biogas <span>yield and, accordingly, the degree of conversion of organic raw materials. </span>Therefore, the rational concentration of Zn<sup>2+</sup> in the fermentation medium is 10 mg/dm<sup>3</sup>.
文摘The article presents an example of a device for focusing ultrasound through the air with the use of computer modeling technology and experimental data processing. The device is a matrix of 172 emitters operating at a frequency of 40 kHz, and the formation of the electronic unit of the ultrasound beam. Beam control on the software from your PC. Radiation pressure at the focal point was 57 Pa, and allows you to move light objects and feel the tactile effect of ultrasound. Present calculations the characteristics of the focused field and results of computer visualization of theoretical and experimental research.
文摘We propose a framework for designing randomized stream ciphers with enhanced security. The key attribute of this framework is using of nonlinear bijective mappings or keyless hash functions for random coding. We investigate the computational security of the proposed ciphers against chosen-plaintext-chosen-initialization-vector attacks and show that it is based on the hardness of solving some systems of random nonlinear Boolean equations. We also provide guidelines for choosing components to design randomizers for specified ciphers.
文摘Surface of oxidized multiwalled carbon nanotubes was investigated for stabilization of nanosized tin（IV） oxide. The synthesis of nanosized tin（IV） oxide on the surface of carbon nanotubes was carried out with the use of three soft chemical methods： sol-gel, precipitation, and thermal. The synthesized tin（IV） oxide particles on the surface of carbon nanotubes were studied by thermal analysis, X-ray diffraction and electron microscopy. The lattice parameters of tin（IV） oxide on the surface of multiwalled carbon nanotubes were calculated.
文摘A variety of liquid thermal solar collectors designs used for water heating have been developed by the previous researchers. But the majority of them do not meet the requirements on small weight, easy assembling and installing, versatility, scalability and adaptability of the design, which are particularly important when they are facade integrated. In order to avoid the above mentioned drawbacks of the liquid thermal collectors, the authors propose to apply to them extruded aluminum alloy made heat pipes of originally designed cross-sectional profile with wide fins and longitudinal grooves. Such solar collectors could be a good solution for building facade and roof integration, because they are assembled of several standard and independent, hermetically sealed and light-weight modules, easy mounted and ＂dry＂ connected to the main pipeline. At that, their thermal performances are not worse than of the other known ones made of heavier and more expensive copper with higher thermal conductance, or having entire rigid designs. Some variants of the developed solar collectors shaping of the assembled modules for building facade or roof integration are proposed. Variously colored coatings to the absorbers are developed and made of carbon-siliceous nano-composites by means of sol-gel method. Their optical performances were compared with ＂anodized black＂. It is stated that colored coatings have a good prospect in thermal SCs （solar collectors） adaptation to building facades decoration, but the works on study and upgrade of their performances should be continued.
文摘The aim of the study of phase shifter on MEMS （micro-electro-mechanical systems） structures was to minimize the dimensions of the design achievement. Also, the main task was to achieve the reliability and durability of the device. The calculation was based on the optimization technique （step by step） and the modeling of individual parts of the device, namely MEMS-keys that perform the main function--switching. The urgency of this problem is the development and study of one device as a universal, that is, automatically switches from two signals simultaneously. Designs are original and devises are the intellectual property of the authors. The program for modeling phase shifters Computer Simulation Technology Microwave Studio and its results are presented in the paper.
文摘<strong>Background & Aim:</strong> Employees’ engagement is a significant organizational competence. Turnover intention is an institutional concern that needs critical analysis of identifying its predictors. Studies have supported the relationship between nurses’ engagement and their desire to leave the organization. This study aims to explore the relationship between work engagement and turnover intention among nurses working in the Kingdom of Bahrain. <strong>Methods: </strong>A cross-sectional design was used for this study. A group of 922 nurses from a major tertiary hospital in the Kingdom of Bahrain was invited to complete the online self-administered survey. The work engagement was assessed using the Utrecht Work Engagement Scale (UWES). The turnover intention was assessed using the 3-item TI Scale based on Mobley <em>et al.</em> survey. The study was conducted in December 2019. <strong>Results: </strong>610 nurses completed the survey on a response rate of (66.2%). The result suggests that nurses expressed high level of work engagement Mean ± Standard Deviation [M = 4.85, SD ± 0.70], and low level of turnover intention [M = 2.29, SD ± 0.94]. Pearson correlation revealed a significant negative relationship between work engagement and turnover intention at <em>p </em>< 0.01. Furthermore, male staff have higher intention to leave. Those working in ambulatory division have higher work engagement than nurses working in critical care division.<strong> Conclusion/practical implication:</strong> It’s paramount for the nurses’ leaders and human resource development practitioners to focus on work engagement dimensions, and developing effective interventions to improve it, which eventually decreases nursing staff’s turnover intention. Retention is more preferable than recruiting, employing, and training new staff. This study confirms the significant relationship between work engagement and turnover intention among nurses.
文摘This paper addresses to the problem of using SAS Enterprise Guide 6.1 as a means for building probabilistic models and as optimum method of modeling gross domestic product in terms of the economic crisis and social threats is proposed. Today in a complex socio-political and economic situation growing influence of external factors, presence of uncertainties and risks there exists a problem of anticipating potential threats in the humanitarian and social spheres and ways to overcome them aiming to provide food security and controllability of ecological situation. All these problems, as reported in the NATO program ＂Science for Peace and Security＂, are of high priority for the countries that need to take into account threats to security, including Ukraine. That is why in the framework of the project NUKR. SFPP G4877 ＂Modeling and Mitigation of Social Disasters Caused by Catastrophes and Terrorism＂ the problems of scientific prediction of national economy for the period to 2030 as one of the measures preventing growth of social tension in the country are disclosed.
基金The authors would like to acknowledge the European Commission Horizon 2020 Program that funded both the ERAPLANET/GEOEssential(Grant Agreement no.689443)ConnectinGEO(Grant Agreement no.641538)projects.
文摘There is a growing recognition of the interdependencies among the supply systems that rely upon food,water and energy.Billions of people lack safe and sufficient access to these systems,coupled with a rapidly growing global demand and increasing resource constraints.Modeling frameworks are considered one of the few means available to understand the complex interrelationships among the sectors,however development of nexus related frameworks has been limited.We describe three opensource models well known in their respective domains(i.e.TerrSysMP,WOFOST and SWAT)where components of each if combined could help decision-makers address the nexus issue.We propose as a first step the development of simple workflows utilizing essential variables and addressing components of the above-mentioned models which can act as building-blocks to be used ultimately in a comprehensive nexus model framework.The outputs of the workflows and the model framework are designed to address the SDGs.
