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    Ivan Lazovic

    ABSTRACT The indoor air quality in schools is very important for health and learning abilities of children. The primary indoor CO2 source in classrooms is the respiration of school building occupants. Also, CO2 comes from outside as a... more
    ABSTRACT The indoor air quality in schools is very important for health and learning abilities of children. The primary indoor CO2 source in classrooms is the respiration of school building occupants. Also, CO2 comes from outside as a result of fossil fuels combustion. CO2 concentration depends on a ventilation rate, size of the classroom, number of occupants and their activity and time they spend in school building. Unfortunately, ventilation rates in schools were not often measured, even in cases when inadequate ventilation caused pupils’ health problems and their absence from school. The increase in indoor CO2 concentration above the outdoor concentration is considered as a good surrogate for the indoor concentrations of bio effluents. This paper presents the research of ventilation rates in five naturally ventilated schools in urban and rural areas in Serbia during the heating season. CO2 concentrations were measured outdoor and in three classrooms for five working days, continually. Ventilation rates are calculated based on measured concentrations of CO2. The results have shown that classrooms in Serbian schools have inadequate ventilation during the heating period. Mean value of carbon dioxide concentration has often been exceeding 1000 ppm.
    Background: Numerous epidemiological studies have associated exposure to PM in the outdoor environment to adverse health effects. Nowadays, the attention is paid to indoor air pollution, since peop...
    The European initiatives for citizens? inclusion in the air quality monitoring process have impacted the participants? knowledge, and attitudes towards air pollution and have led to a higher sense of community toward activities and... more
    The European initiatives for citizens? inclusion in the air quality monitoring process have impacted the participants? knowledge, and attitudes towards air pollution and have led to a higher sense of community toward activities and measures against air pollution. In the Republic of Serbia, an experiment with self-made sensor kits "Klimerko ? Air to the Citizens" started in 2018. In this paper, we have presented the level of agreement of the particulate matter (PM) readings from selected Klimerko devices to the PM readings of the reference equivalent PM monitors from the National Air Quality Monitoring Network in the cities of Bor and Belgrade. The Klimerko devices that we tested showed excellent stability and reliability during the comparison period. The conclusion of our investigation is that the properly calibrated Klimerko devices could be applied for indicative measurements of PM mass concentrations in the ambient air.
    Homogeneity of the flue gas-flow through the chamber of an electrostatic precipitator is one of the basic influencing parameter on dedusting efficiency. This paper presents results of a multiobjective optimization study of the flue gas... more
    Homogeneity of the flue gas-flow through the chamber of an electrostatic precipitator is one of the basic influencing parameter on dedusting efficiency. This paper presents results of a multiobjective optimization study of the flue gas controlling devices of electrostatic precipitator of 324 MWe lignite fired Unit A4 of TPP "Nikola Tesla" in Serbia. The aim was to achieve better flow homogeneity in the cross-section of the precipitator compared to the original design. Additional constraints were to maintain the minimum as possible overall weight of the proposed design as well as pressure drop through the precipitator. Numerical simulations based on CFD were used to investigate dependence of the velocity distribution in the ducts and precipitator?s chamber with respect to the geometrical parameters of tested concepts of turning blades. A series of 22 detailed full-scale numerical models of the precipitator with different concepts of turning vanes designs were developed. Ass...
    ABSTRACT The indoor air quality in schools is very important for health and learning abilities of children. The primary indoor CO2 source in classrooms is the respiration of school building occupants. Also, CO2 comes from outside as a... more
    ABSTRACT The indoor air quality in schools is very important for health and learning abilities of children. The primary indoor CO2 source in classrooms is the respiration of school building occupants. Also, CO2 comes from outside as a result of fossil fuels combustion. CO2 concentration depends on a ventilation rate, size of the classroom, number of occupants and their activity and time they spend in school building. Unfortunately, ventilation rates in schools were not often measured, even in cases when inadequate ventilation caused pupils’ health problems and their absence from school. The increase in indoor CO2 concentration above the outdoor concentration is considered as a good surrogate for the indoor concentrations of bio effluents. This paper presents the research of ventilation rates in five naturally ventilated schools in urban and rural areas in Serbia during the heating season. CO2 concentrations were measured outdoor and in three classrooms for five working days, continually. Ventilation rates are calculated based on measured concentrations of CO2. The results have shown that classrooms in Serbian schools have inadequate ventilation during the heating period. Mean value of carbon dioxide concentration has often been exceeding 1000 ppm.
    Background: Numerous epidemiological studies have associated exposure to PM in the outdoor environment to adverse health effects. Nowadays, the attention is paid to indoor air pollution, since peop...
    The European initiatives for citizens? inclusion in the air quality monitoring process have impacted the participants? knowledge, and attitudes towards air pollution and have led to a higher sense of community toward activities and... more
    The European initiatives for citizens? inclusion in the air quality monitoring process have impacted the participants? knowledge, and attitudes towards air pollution and have led to a higher sense of community toward activities and measures against air pollution. In the Republic of Serbia, an experiment with self-made sensor kits "Klimerko ? Air to the Citizens" started in 2018. In this paper, we have presented the level of agreement of the particulate matter (PM) readings from selected Klimerko devices to the PM readings of the reference equivalent PM monitors from the National Air Quality Monitoring Network in the cities of Bor and Belgrade. The Klimerko devices that we tested showed excellent stability and reliability during the comparison period. The conclusion of our investigation is that the properly calibrated Klimerko devices could be applied for indicative measurements of PM mass concentrations in the ambient air.
    Homogeneity of the flue gas-flow through the chamber of an electrostatic precipitator is one of the basic influencing parameter on dedusting efficiency. This paper presents results of a multiobjective optimization study of the flue gas... more
    Homogeneity of the flue gas-flow through the chamber of an electrostatic precipitator is one of the basic influencing parameter on dedusting efficiency. This paper presents results of a multiobjective optimization study of the flue gas controlling devices of electrostatic precipitator of 324 MWe lignite fired Unit A4 of TPP "Nikola Tesla" in Serbia. The aim was to achieve better flow homogeneity in the cross-section of the precipitator compared to the original design. Additional constraints were to maintain the minimum as possible overall weight of the proposed design as well as pressure drop through the precipitator. Numerical simulations based on CFD were used to investigate dependence of the velocity distribution in the ducts and precipitator?s chamber with respect to the geometrical parameters of tested concepts of turning blades. A series of 22 detailed full-scale numerical models of the precipitator with different concepts of turning vanes designs were developed. Ass...
    Greenhouse gases emission as well as total energy consumption in buildings of public importance, such as schools, municipal buildings, health care centers, can be significantly reduced by increasing buildings? energy efficiency.... more
    Greenhouse gases emission as well as total energy consumption in buildings of public importance, such as schools, municipal buildings, health care centers, can be significantly reduced by increasing buildings? energy efficiency. Buildings? energy consumption adds up to 37% of total energy consumption in the EU countries. In the Republic of Serbia this amount is significantly higher, about 50%. School buildings are considered as one of the most diverse structures from the point of energy-efficient design and construction. The main aim of this paper is to determine the most appropriate settings for possible improvements in energy efficiency and temperature comfort inside a typical primary school classroom in Serbia. The energy efficiency analysis was performed during the heating season for the naturally ventilated primary school classroom located in the eastern Serbia region. The analysis was performed using novel CFD model, suggested in this paper. The suggested model was used to sol...
    The research presents an experiment with a model of an electronic generator for energy injection into the plasma of a fusion reactor. By recording a non-ionizing field in the vicinity of a fusion reactor, it was determined that this field... more
    The research presents an experiment with a model of an electronic generator for energy injection into the plasma of a fusion reactor. By recording a non-ionizing field in the vicinity of a fusion reactor, it was determined that this field has an extremely high growth rate. At the site of the maximum intensity of the field of non-ionizing radiation, commercial surge arresters with a flexible model of surge arresters were used for experimentation. It has been found that the commercial surge arresters have an efficiency of about 20%. For the efficiency of the flexible model, it was found to be slightly less than 40% (and to be achieved by the application of alpha particle radiation). Since neither of these efficiencies guarantee reliable operation of the gas-filled surge arrester, it was concluded that essential electronics in the vicinity of the fusion generator must be protected. However, since this protection can only be implemented in a fusion reactor, the fact remains that the env...
    Substantial knowledge is available on the association of the indoor school environment and its effect among schoolchildren. In the same context, the SINPHONIE (School indoor pollution and health: Observatory network in Europe) conducted a... more
    Substantial knowledge is available on the association of the indoor school environment and its effect among schoolchildren. In the same context, the SINPHONIE (School indoor pollution and health: Observatory network in Europe) conducted a study to collect data and determine the distribution of several indoor air pollutants (IAPs), physical and thermal parameters and their association with eye, skin, upper-, lower respiratory and systemic disorder symptoms during the previous three months. Finally, data from 115 schools in 54 European cities from 23 countries was collected and included 5175 schoolchildren using a harmonized and standardized protocol. The association between exposures and the health outcomes were examined using logistic regression models on individual indoor air pollutants (IAPs); a VOC (volatile organic compound) score defined as the sum of the number of pollutants to which the children were highly exposed (concentration > median of the distribution) in classroom was also introduced to evaluate the multiexposure - outcome association, while adjusting for several confounding factors. Schoolchildren exposed to above or equal median concentration of PM2.5, benzene, limonene, ozone and radon were at significantly higher odds of suffering from upper, lower airways, eye and systemic disorders. Increased odds were also observed for any symptom (sick school syndrome) among schoolchildren exposed to concentrations of limonene and ozone above median values. Furthermore, the risks for upper and lower airways and systemic disorders significantly increased with the VOCs score. Results also showed that increased ventilation rate was significantly associated with decreased odds of suffering from eye, skin disorders whereas similar association was observed between temperature and upper airways symptoms. The present study provides evidence that exposure to IAPs in schools is associated with allergic and respiratory symptoms in children. Further investigations are needed to confirm our findings.
    The electrostatic precipitator system of the lignite fired 350 MWe unit B1 of Thermal Power Plant Kostolac B has been modernized during 2014. The results of complex in site measurements, performed in the frame of performance control test... more
    The electrostatic precipitator system of the lignite fired 350 MWe unit B1 of Thermal Power Plant Kostolac B has been modernized during 2014. The results of complex in site measurements, performed in the frame of performance control test at the beginning of the exploitation period of the upgraded electrostatic precipitator proved that, under normal and guarantee working conditions of the boiler and precipitator, the emission of particulate matter do not exceed limiting value. After the period of precipitator further adjustments, five series of measurements in the frame of acceptance test were performed in accordance with relevant standards. This paper presents results of the investigation of particulate matter concentration, laboratory analysis of the lignite, fly and bottom ash samples, working parameters of the unit and upgraded electrostatic precipitator as well as results of the calculations. The averaged mean particulate concentration at the exit of upgraded electrostatic preci...
    Sustainable development indicators mainly provide information that can link the observed energy system with sustainable development. This paper considers building energy indicators in order to provide monitoring and measurement of energy... more
    Sustainable development indicators mainly provide information that can link the observed energy system with sustainable development. This paper considers building energy indicators in order to provide monitoring and measurement of energy performance of buildings. The results of measurement which are considered were obtained in school buildings in Serbia. The aim of this paper is to select, define, and calculate energy indicators as criteria for evaluating the quality of public buildings, with regard to sustainable development. The criteria for assessing sustainability are quantified by certain defined sets of economic, social and environmental indicators. The ASPID method of multi-criteria analysis is also described and mathematically presented. This method is based on the synthesis technique of fuzzy sets and the sustainability of the school buildings was based on their assessment as complex energy systems.
    Previous studies have shown that poorly ventilated classrooms can have negative impact on the health of children and school staff. In most cases, schools in Serbia are ventilated naturally. Considering their high occupancy, classroom air... more
    Previous studies have shown that poorly ventilated classrooms can have negative impact on the health of children and school staff. In most cases, schools in Serbia are ventilated naturally. Considering their high occupancy, classroom air quality test determines the level of air pollution, after which it is possible to implement corrective measures. The research presented in this study was conducted in four schools which are located in different areas and have different architecture designs. Measurements in these schools have been performed during the winter (heating season) and spring (non-heating season) and the following results were presented: indoor air temperature, relative humidity and carbon dioxide concentration. These results show that the classroom average concentration of carbon dioxide often exceeds the value of 1500 ppm, during its full occupancy, which indicates inadequate ventilation. Measurement campaigns show that carbon dioxide concentration increased significantly...
    Research Interests:
    Research Interests:
    The central concern of indoor air quality (IAQ) analysis is the prediction of airborne contaminant dispersal in buildings. Airborne contaminants disperse throughout buildings in a complex manner that depends on many parameters: the nature... more
    The central concern of indoor air quality (IAQ) analysis is the prediction of airborne contaminant dispersal in buildings. Airborne contaminants disperse throughout buildings in a complex manner that depends on many parameters: the nature of air movements (in-to, out-of and within the building system), the influence of the heating and natural ventilation, the possibility of removal by filtration or contribution, by generation of contaminants etc. For IAQ analysis we seek to comprehensively model all of these phenomena. The aim of this paper is to present methodology used for determination of airflow and contaminant related phenomena. Subsequently, the goal was to model and investigate possible indoor contaminant behavior as a result of implementation of building energy efficiency measures and GHG emission mitigation scenarios. As a reference example representation, modeling and simulation performance of one typical Belgrade dwelling has been performed. It incorporates developing of ...
    Indoor air quality (IAQ) is very important for children health and well-being, since children are particularly vulnerable and sensitive on presence of air pollutants. This study was performed in two naturally ventilated schools located in... more
    Indoor air quality (IAQ) is very important for children health and well-being, since children are particularly vulnerable and sensitive on presence of air pollutants. This study was performed in two naturally ventilated schools located in the same municipality. First school is located in urban area, at residential - industrial site, while the other school is situated in rural area. School buildings were chosen based on their urban environment features. The measurements were carried out in heating as well as in non-heating period in duration of five consecutive working days. The objective of the study was to analyze IAQ in the classrooms with special emphasis on levels and diurnal variations of particulate matter (PM10 and PM2.5), carbon dioxide (CO2) and nitrogen dioxide (NO2) in occupied and unoccupied school classrooms. In this paper, the CO2 concentrations were measured at both indoor and outdoor environments. Concentrations of CO2 higher than 1000 ppm were regularly detected in ...
    This study investigated seasonal variation of PAHs and their partition between gas and particulate-bounded phases in indoor and outdoor air in 4 schools in Serbia located at different locations. The sampling campaigns were conducted... more
    This study investigated seasonal variation of PAHs and their partition between gas and particulate-bounded phases in indoor and outdoor air in 4 schools in Serbia located at different locations. The sampling campaigns were conducted during one workweek at each school successively. Campaigns were conducted in schools during heating and non-heating seasons in December 2011 and June 2012. Seasonal variations of gas and particle-bounded PAHs concentrations were observed with higher levels during heating season. The highest total PAH values were associated with the gas phase in both sampling periods. The total PAHs concentration at indoor and at the outdoor sites, during heating season, ranged from 88.45 to 447.72 ng/m3 and 201.69 to 1017.15 ng/m3, respectively. During non-heating season, the total PAHs concentration ranged from 36.91 to 271.57 ng/m3 in indoor environment and 27.00 to 132.32 ng/m3 in outdoor environment. Most of the I/O ratios were less than 1, which indicated that the i...
    ABSTRACT The indoor air quality in schools is very important for health and learning abilities of children. The primary indoor CO2 source in classrooms is the respiration of school building occupants. Also, CO2 comes from outside as a... more
    ABSTRACT The indoor air quality in schools is very important for health and learning abilities of children. The primary indoor CO2 source in classrooms is the respiration of school building occupants. Also, CO2 comes from outside as a result of fossil fuels combustion. CO2 concentration depends on a ventilation rate, size of the classroom, number of occupants and their activity and time they spend in school building. Unfortunately, ventilation rates in schools were not often measured, even in cases when inadequate ventilation caused pupils’ health problems and their absence from school. The increase in indoor CO2 concentration above the outdoor concentration is considered as a good surrogate for the indoor concentrations of bio effluents. This paper presents the research of ventilation rates in five naturally ventilated schools in urban and rural areas in Serbia during the heating season. CO2 concentrations were measured outdoor and in three classrooms for five working days, continually. Ventilation rates are calculated based on measured concentrations of CO2. The results have shown that classrooms in Serbian schools have inadequate ventilation during the heating period. Mean value of carbon dioxide concentration has often been exceeding 1000 ppm.