Academic literature on the topic 'Age dependence of pollutant concentrations'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Age dependence of pollutant concentrations.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Age dependence of pollutant concentrations"

1

N., Bravo, Hansen S., Økland I., et al. "Influence of maternal and sociodemographic characteristics on the accumulation of organohalogen compounds in Argentinian women. The EMASAR study." Environmental Research 158 (October 1, 2017): 759–67. https://doi.org/10.1016/j.envres.2017.07.033.

Full text
Abstract:
The occurrence of organohalogen compounds in venous serum from post-partum mothers from two Argentinian cities, Salta and Ushuaia, has been investigated (n = 698). 4,4'-DDE was the most abundant compound in these cities, with geometric means of 33 and 67ng/g lipid weight, respectively. City of residence, age and parity were the main determinants of the accumulation of these compounds. Hexachlorobenzene (HCB) was the second most abundant pollutant in Ushuaia, 8.7ng/g lipid, and β-hexachlorocyclohexane (β-HCH) in Salta, 7.8ng/g lipid. Decabromodiphenyl ether was higher in Ushuaia than Salta, 8.2 and 4.1ng/g lipid, respectively. The predominance of β-HCH, 4,4'-DDE and 4,4'-DDT in Salta was related with higher use of pesticides for agricultural applications. The observed higher concentrations of 4,4'-DDE and 4,4'-DDT in the mothers from rural+semi-urban sites than in urban areas were consistent with this agricultural origin. In addition, the most volatile organochlorine compounds included in this study, HCB and α-HCH, were mainly found in Ushuaia. The concentrations of the studied organohalogen pollutants in Argentina were lower than those found in other similar studies which is consistent with the location of these cities in the southern hemisphere. Age, mainly for 4,4'-DDE and polychlorobiphenyl (PCB) congeners 138, 153 and 180, and parity, mainly for HCB, β-HCH, 4,4'-DDT and PCB congener 118, were the second main determinants of the concentrations of these compounds. Gestational weight gain also influenced on the maternal levels of HCB, β-HCH, 4,4'-DDT and PCB congeners 118, 138 and 153. Higher weight accumulation during pregnancy involved dilution of these persistent pollutants. Body mass index (BMI) was a statistically significant determinant for 4,4'-DDT, α-HCH and PCB congeners 153 and 180. The observed direct correspondence between higher BMI and 4,4'-DDT concentrations was in agreement with the above reported inputs related with agricultural applications. The reverse correspondence of BMI with α-HCH and the PCB congeners indicated higher dilution at higher weight increase.
APA, Harvard, Vancouver, ISO, and other styles
2

Efimova, Natalia V., Marina V. Kuzmina, and Elena V. Bobkova. "Assessment of the annual trend of chemical aerogenic risk to health and mortality of the population at an industrial center." Hygiene and sanitation 102, no. 12 (2023): 1375–80. http://dx.doi.org/10.47470/0016-9900-2023-102-12-1375-1380.

Full text
Abstract:
Introduction. Ambient air pollution determines high levels of risk to public health, causing excess mortality. 
 The purpose of the study is to analyze the dependence of the seasonal dynamics of pollutants and mortality from major non-infectious diseases in the population of the industrial center of Eastern Siberia.
 Materials and methods. Air pollution in Bratsk was assessed based on data from monitoring systems for 2017–2022, taking into account one-time, average monthly and annual concentrations. Hazard indices and mortality rates (MR) from major causes were calculated. The annual trend in indicators are assessed using seasonality indices (SI).
 Results. Features of the seasonal dynamics of pollutants were revealed: maximum fluctuations in SI are characteristic of benzo(a)pyrene (22% in the warm season, 214% in the cold season), formaldehyde (219 and 65%, respectively). The SI for mortality had significant fluctuations throughout the year and varied across age groups and disease classes. Changes in seasonality have been noted during the COVID-19 pandemic. Average monthly MR in the older group is associated with concentrations of PM2.5, formaldehyde, NO2.
 Limitations of the study are related to the limited data on monitoring pollutants, inevitable errors in conditional division into seasons, and the impossibility 
 of accurately determining the cause of death during a pandemic.
 Conclusion. The use of average monthly data on MR values and pollutant concentrations confirms the dependence of population mortality on air pollution when studying this phenomenon in medium-sized cities with high levels of hazard indices.
APA, Harvard, Vancouver, ISO, and other styles
3

Marrone, Erica, Cristina Longo, Jennifer O’Loughlin, et al. "Association between annual exposure to air pollution and systolic blood pressure among adolescents in Montréal, Canada." Health Promotion and Chronic Disease Prevention in Canada 43, no. 4 (2023): 191–98. http://dx.doi.org/10.24095/hpcdp.43.4.04.

Full text
Abstract:
Introduction In adults, chronic exposure to air pollution is associated with elevated blood pressure, but few studies have examined this relationship in youth. We investigated the association between annual ambient concentrations of air pollutants (fine particulate matter [PM2.5] and nitrogen dioxide [NO2]) and systolic blood pressure (SBP) among adolescents in Montréal, Canada. Methods Participants were students aged 15 to 17 years who provided SBP and residential postal code data in 2004/05 through their enrolment in the Nicotine Dependence in Teens study. Annual estimates for 2004 of residential exposure to NO2 and PM2.5 were provided by the Canadian Urban Environmental Health Research Consortium and linked to participants’ residential postal code. Elevated SBP was defined as SBP ≥ 90th percentile adjusted for age, sex and height. Logistic regression was used to estimate odds ratios and 95% confidence intervals (CIs) for each pollutant with respect to elevated SBP, adjusted for relevant confounders. Results The sample consisted of 508 adolescents (mean age: 16.9, 46% male); 4% had elevated SBP. Although estimates were not statistically significant, there were generally modest positive associations between pollutant levels and SBP. The adjusted prevalence odds ratio of elevated SBP was 1.33 (95% CI: 0.64, 3.05) for every interquartile range (IQR) increase in residential PM2.5 levels (2.1μg/m3). Similarly, the adjusted prevalence odds ratio of elevated SBP was 1.17 (95% CI: 0.47, 2.70) for every IQR increase in residential NO2 levels (10.2 ppb). Conclusion Findings support a possible relationship between exposure to air pollutants and increased SBP in adolescents, warranting further investigation for this important public health concern.
APA, Harvard, Vancouver, ISO, and other styles
4

Galil, N., and M. Rebhun. "Primary Chemical Treatment Minimizing Dependence on Bioprocess in Small Treatment Plants." Water Science and Technology 22, no. 3-4 (1990): 203–10. http://dx.doi.org/10.2166/wst.1990.0202.

Full text
Abstract:
In wastewater from small communities, institutions, hotels, camps and tourist areas the major pollutants such as organic matter, oil and grease and organic nitrogen are mainly in particulate form, while the soluble fractions of organics and nitrogen are low. This is due to the short residence times in the sewerage systems preventing decomposition and lysis. Such wastewaters are also characterized by high variations in pollution load, mostly in the particulate fraction. Small plants, treating wastewater for discharge to lakes or rivers, have to remove organic pollutants and nutrients, mainly phosphorus. Chemical flocculation-sedimentation, as primary treatment, was considered a promising process combination to obtain reliable operation and for minimizing effects of variations in flow and load. Two possible process combinations were studied: a. chemical flocculation-sedimentation as primary stage, followed by biotreatment (CBT); b. biotreatment of raw wastewater, followed by chemical flocculation-sedimentation (BCT). It was found that primary chemical treatment by alum, or lime, removes more than 90 percent of the suspended solids, colloids, phosphates, oil and grease; the organic matter as BOD and organic nitrogen removals were about 70 percent. By removing the particulate organic matter and other disturbing factors the successive bioprocess in CBT was substantially improved: the growth rate constants for general biomass and for nitrifiers as well as the removal rates were higher for CBT than for BCT; the critical sludge age for nitrification in CBT was 4 days, as compared to 10 days in BCT. The reduction of organic load by about 70 percent, producing a more uniform influent and the better bio-kinetics achieved in CBT, enable a considerable economy in the bioreactor volume and lower energy requirement. Experimental results showed that the CBT sequence enables lower sludge production containing higher concentrations of solids, most of them inorganic.
APA, Harvard, Vancouver, ISO, and other styles
5

Nguyen, Thi Thui Nhung, and Irina Vladimirovna Volkova. "Mercury accumulation in bivalve molluscs in hydroecosystem of Red River estuary (Vietnam)." Vestnik of Astrakhan State Technical University. Series: Fishing industry 2023, no. 1 (2023): 82–88. http://dx.doi.org/10.24143/2073-5529-2023-1-82-88.

Full text
Abstract:
The article presents analysis of mercury content in different tissues such as gills, mantle, hepatopancreas and body (leg) in 4 species of bivalve molluscs in the estuary of the Red River in Vietnam. The studies were carried out in 2016–2021 during the main hydrological seasons (during the summer flood and winter low water) at 37 stations in the delta and estuarine coast of the Red River. There are shown the dependences of mercury content in mollusc tissues on the age parameters (length and mass of tissues) and on the content of pollutant in dissolved, suspended forms of near-bottom water layers and in bottom sediments. The mercury content in the tissues of molluscs varies whithin 0,023 ± 0,001 to 0,459 ± 0,007 mg/kg wet weight. The highest content of mercury was found in the hepatopancreas 
 of Austriella corrugata, and the lowest - in the leg of Lutraria rhynchaena. Significant close positive correlations were registered between the mercury concentrations in the mollusc tissues and the mercury content in the near-bottom water layer and in bottom sediments (r from 0.68 to 0.92, p < 0.05). All studied species of molluscs are classified as macroconcentrators of mercury in water; Austriella corrugata can actively accumulate mercury not only from the water, but also from the bottom sediments. Bivalve molluscs can be used as an object of biomonitoring when studying the distribution of mercury in the estuary of the Red River.
APA, Harvard, Vancouver, ISO, and other styles
6

Tereshchenko, Tatyana, Galina Sroslova, Margarita Postnova, Yuliya Zimina, and Mikhail Sroslov. "Influence of Anthropogenic Factors on the State of Woody Plants in Volgograd." Natural Systems and Resources, no. 1 (May 2021): 5–11. http://dx.doi.org/10.15688/nsr.jvolsu.2021.1.1.

Full text
Abstract:
Studies conducted in different cities have shown that trees growing in urbanized areas reduce noise levels and cleanse the air of solid particles, ozone, sulfur dioxide, carbon monoxide, nitric oxide and other pollutants contained in car fumes, transport dust and generated by industry. The reaction to the influence of negative factors in woody plants is in disturbances in metabolism and biochemical composition, their general development also changes, and their population decreases. The indicators of disorders occurring at the cellular and tissue levels are more sensitive to the influence of negative anthropogenic factors in comparison with external manifestations. The research was carried out on woody plants: small-leaved linden (L. Tíliacordáta), horse chestnut (L. Aésculus); the soil. The research was carried out in 9 districts of Volgograd. The assessment of the state of woody plants was carried out by the visual method based on external signs. GOST methods were used to determine the concentrations of chemical elements in the foliage and soil of woody plants. Using physical and chemical methods, the concentrations of chemical elements in the soil and biomass of woody plants taken from the selected areas of the city of Volgograd were obtained, and the correlation between these indicators and the life state of woody plants was determined. The dependence of the indicators of the concentration of nutrients in the soil and the state and viability of woody plants was well traced. In general, the state of most of the woody plants of the city was healthy or moderately weakened. Such a high level of the life state is explained by the relatively young age structure of the studied plants, because at a young age woody plants are more resistant to negative factors of the urban environment. The revealed features of the life of woody plants in the city can be taken into account in the practice of city green building.
APA, Harvard, Vancouver, ISO, and other styles
7

Kozlova, Anastasia, Marina Stepantsevich, Vladislav Kukartsev, Aleksey Losev, and Natalya Yagudaeva. "Statistical analysis of seasonal variations in pollutant concentrations in urban atmosphere." E3S Web of Conferences 592 (2024): 06010. http://dx.doi.org/10.1051/e3sconf/202459206010.

Full text
Abstract:
In the context of global climate change and urbanization, the issue of air quality is becoming increasingly relevant. Air pollution poses a threat to human health and ecosystems, highlighting the need for monitoring the concentrations of pollutants. This study examines the seasonal variations in the concentrations of harmful substances in the urban atmosphere using statistical methods. The aim of the research is to analyze time series data on concentrations of carbon monoxide (CO), nitrogen oxide (NO), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), ammonia (NH3), and particulate matter (PM2.5 and PM10). Correlation and factor analysis are employed to assess the relationships between pollutants and identify underlying factors. The analysis of data collected over several years emphasizes seasonal changes, showing that pollutant concentrations are subject to significant fluctuations driven by both natural and anthropogenic factors. The results can be used to develop strategies for improving air quality and predicting the health impacts of pollution on the population. This research deepens the understanding of the dynamics of atmospheric pollution and its seasonal dependence, which is important for shaping environmental policy and management decisions.
APA, Harvard, Vancouver, ISO, and other styles
8

Chan, Edward C., and Timothy M. Butler. "urbanChemFoam 1.0: large-eddy simulation of non-stationary chemical transport of traffic emissions in an idealized street canyon." Geoscientific Model Development 14, no. 7 (2021): 4555–72. http://dx.doi.org/10.5194/gmd-14-4555-2021.

Full text
Abstract:
Abstract. This paper describes a large-eddy simulation based chemical transport model, developed under the OpenFOAM framework, implemented to simulate dispersion and chemical transformation of nitrogen oxides from traffic sources in an idealized street canyon. The dynamics of the model, in terms of mean velocity and turbulent fluctuation, are evaluated using available stationary measurements. A transient model run using a photostationary reaction mechanism for nitrogen oxides and ozone subsequently follows, where non-stationary conditions for meteorology, background concentrations, and traffic emissions are applied over a 24 h period, using regional model data and measurements obtained for the city of Berlin in July 2014. Diurnal variations of pollutant concentrations indicate dependence on emission levels, background concentrations, and solar state. Comparison of vertical and horizontal profiles with corresponding stationary model runs at select times show that while there are only slight differences in velocity magnitude, visible changes in primary and secondary flow structures can be observed. In addition, temporal variations in diurnal profile and cumulative species concentration result in significant deviations in computed pollutant concentrations between transient and stationary model runs.
APA, Harvard, Vancouver, ISO, and other styles
9

Girgždienė, Raselė, and Radvilė Rameikytė. "VARIATION OF PM10 MASS AND AEROSOL NUMBER CONCENTRATIONS IN ŠIAULIAI." JOURNAL OF ENVIRONMENTAL ENGINEERING AND LANDSCAPE MANAGEMENT 15, no. 1 (2007): 47–53. http://dx.doi.org/10.3846/16486897.2007.9636907.

Full text
Abstract:
The urban environment is distinguished by higher aerosol and gaseous pollutant concentrations than those in rural areas. A study of aerosol pollutant behavior was performed in an industrial Lithuanian city of Šiauliai. The PM10 mass concentration and meteorological parameter monitoring data were analysed. The aerosol number concentration was measured during a 10‐day experiment in Šiauliai. Analysis of PM10 showed that the workdays‐weekends phenomenon in the PM10 mass concentration distribution was prevailing. The PM10 mass concentration on workdays was higher in comparison with the concentration at weekends, 24,6 μg/m3 and 21 μg/m3, respectively. Clear PM10 mass concentration dependence on the wind parameters (speed and direction) was found. Linear relationship between aerosol number and PM10 mass concentrations was found at a high particle number concentration (more than 18000 cm−3). PM10 level in Šiauliai was defined as a sum of three sources: regional background, urban background and local sources. Contribution of these sources to the total PM10 mass concentration was estimated to be 36 %, 30 % and 34 %, respectively, during June‐October of 2005.
APA, Harvard, Vancouver, ISO, and other styles
10

Khuriganova, Olga I., Vladimir A. Obolkin, Liudmila P. Golobokova, Yuri S. Bukin, and Tamara V. Khodzher. "Passive Sampling as a Low-Cost Method for Monitoring Air Pollutants in the Baikal Region (Eastern Siberia)." Atmosphere 10, no. 8 (2019): 470. http://dx.doi.org/10.3390/atmos10080470.

Full text
Abstract:
The measured concentrations of inorganic pollutants, such as ozone (2015–2018), sulfur, and nitrogen oxides (2012–2018) at air monitoring sites in the south of Eastern Siberia were sampled, following the passive sampling method, and analyzed. The spatial inhomogeneity of atmospheric gas concentrations is presented. The ozone concentration is lower in urban areas than those in rural areas and the background level. However, the nitrogen and sulfur oxide concentrations are higher in the atmosphere over the city site. The seasonal dependence of the ozone concentration was determined using its maximum (March–April) and minimum (September–October) levels. The dynamics of the nitrogen and sulfur oxide concentrations indicate that they are at their highest in December–June and their lowest in July–August. To verify the validity of the pollutant concentration measurements sampled by passive sampling, we compared our results with those obtained following the automatic and filter pack methods. A linear regression analysis and a pairwise modification of Student’s t test evaluated the concentrations of the air pollutant, sampled and measured using different methods, and they correlate well (r = 0.7–0.9). Full validation of the passive sampling method is not possible for some sites; therefore it is necessary to remove the remaining systematic errors in future work.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Age dependence of pollutant concentrations"

1

Vuorinen, Ilppo. Post-Glacial Baltic Sea Ecosystems. Oxford University Press, 2018. http://dx.doi.org/10.1093/acrefore/9780190228620.013.675.

Full text
Abstract:
Post-glacial aquatic ecosystems in Eurasia and North America, such as the Baltic Sea, evolved in the freshwater, brackish, and marine environments that fringed the melting glaciers. Warming of the climate initiated sea level and land rise and subsequent changes in aquatic ecosystems. Seminal ideas on ancient developing ecosystems were based on findings in Swedish large lakes of species that had arrived there from adjacent glacial freshwater or marine environments and established populations which have survived up to the present day. An ecosystem of the first freshwater stage, the Baltic Ice Lake initially consisted of ice-associated biota. Subsequent aquatic environments, the Yoldia Sea, the Ancylus Lake, the Litorina Sea, and the Mya Sea, are all named after mollusc trace fossils. These often convey information on the geologic period in question and indicate some physical and chemical characteristics of their environment. The ecosystems of various Baltic Sea stages are regulated primarily by temperature and freshwater runoff (which affects directly and indirectly both salinity and nutrient concentrations). Key ecological environmental factors, such as temperature, salinity, and nutrient levels, not only change seasonally but are also subject to long-term changes (due to astronomical factors) and shorter disturbances, for example, a warm period that essentially formed the Yoldia Sea, and more recently the “Little Ice Age” (which terminated the Viking settlement in Iceland).There is no direct way to study the post-Holocene Baltic Sea stages, but findings in geological samples of ecological keystone species (which may form a physical environment for other species to dwell in and/or largely determine the function of an ecosystem) can indicate ancient large-scale ecosystem features and changes. Such changes have included, for example, development of an initially turbid glacial meltwater to clearer water with increasing primary production (enhanced also by warmer temperatures), eventually leading to self-shading and other consequences of anthropogenic eutrophication (nutrient-rich conditions). Furthermore, the development in the last century from oligotrophic (nutrient-poor) to eutrophic conditions also included shifts between the grazing chain (which include large predators, e.g., piscivorous fish, mammals, and birds at the top of the food chain) and the microbial loop (filtering top predators such as jellyfish). Another large-scale change has been a succession from low (freshwater glacier lake) biodiversity to increased (brackish and marine) biodiversity. The present-day Baltic Sea ecosystem is a direct descendant of the more marine Litorina Sea, which marks the beginning of the transition from a primeval ecosystem to one regulated by humans. The recent Baltic Sea is characterized by high concentrations of pollutants and nutrients, a shift from perennial to annual macrophytes (and more rapid nutrient cycling), and an increasing rate of invasion by non-native species. Thus, an increasing pace of anthropogenic ecological change has been a prominent trend in the Baltic Sea ecosystem since the Ancylus Lake.Future development is in the first place dependent on regional factors, such as salinity, which is regulated by sea and land level changes and the climate, and runoff, which controls both salinity and the leaching of nutrients to the sea. However, uncertainties abound, for example the future development of the Gulf Stream and its associated westerly winds, which support the sub-boreal ecosystems, both terrestrial and aquatic, in the Baltic Sea area. Thus, extensive sophisticated, cross-disciplinary modeling is needed to foresee whether the Baltic Sea will develop toward a freshwater or marine ecosystem, set in a sub-boreal, boreal, or arctic climate.
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Age dependence of pollutant concentrations"

1

Jiang, P., I. Bychkov, J. Liu, and A. Hmelnov. "Predicting of air pollutant concentrations based on spatio-temporal attention convolutional LSTM networks." In 1st International Workshop on Advanced Information and Computation Technologies and Systems 2020. Crossref, 2021. http://dx.doi.org/10.47350/aicts.2020.09.

Full text
Abstract:
Forecasting of air pollutant concentration, which is influenced by air pollution accumulation, traffic flow and industrial emissions, has attracted extensive attention for decades. In this paper, we propose a spatio-temporal attention convolutional long short term memory neural networks (Attention-CNN-LSTM) for air pollutant concentration forecasting. Firstly, we analyze the Granger causalities between different stations and establish a hyperparametric Gaussian vector weight function to determine spatial autocorrelation variables, which is used as part of the input feature. Secondly, convolutional neural networks (CNN) is employed to extract the temporal dependence and spatial correlation of the input, while feature maps and channels are weighted by attention mechanism, so as to improve the effectiveness of the features. Finally, a depth long short term memory (LSTM) based time series predictor is established for learning the long-term and short-term dependence of pollutant concentration. In order to reduce the effect of diverse complex factors on LSTM, inherent features are extracted from historical air pollutant concentration data meteorological data and timestamp information are incorporated into the proposed model. Extensive experiments were performed using the Attention-CNNLSTM, autoregressive integrated moving average (ARIMA), support vector regression (SVR), traditional LSTM and CNN, respectively. The results demonstrated that the feasibility and practicability of Attention-CNN-LSTM on estimating CO and NO concentration.
APA, Harvard, Vancouver, ISO, and other styles
2

Hutter, Marek, Radomir Scurek, and Vera Holubova. "STUDY OF THE INFLUENCE OF DRONES ON THE MEASUREMENT OF AIR POLLUTANTS." In 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022/4.1/s19.51.

Full text
Abstract:
Unmanned aerial vehicles (UAV) began being constructed many decades ago. Recently - in line with technological developments - there has also been a progression of its expansion, both among the lay public and its dynamic integration within the security services. One of the desired functionalities of the drones is the continuous measurement of air pollution at the scene of a fire. This paper deals with the question of whether drones, due to the rotation of their rotors, do not affect the values of air pollution, the concentration of which is detected by a detector located on the drone. To confirm or refute this hypothesis, an experiment was designed and conducted, which should simulate the conditions arising from the fire. A drone was also used, which is intended for direct reconnaissance of the terrain at the place of intervention by fire protection units. The continuous concentration of selected dominant toxic emissions was then measured with a sensitive detector - aspirating smoke detector with continuous air sampling CO, CO2, NO - TESTO 350 � XL The results of this experiment were then processed mathematically and graphically. It was found out that drones have no physical effect on the measurement concentration The results obtained from the experiment are important for drone designers and for firefighters, who are very dependent on reliable data in the event of an intervention.
APA, Harvard, Vancouver, ISO, and other styles
3

Vidanapathirana, M., N. Perera, R. Emmanuel, and S. Coorey. "Can Colombo port city high-rise tower and podium morphology improve pollutant dispersion and urban ventilation?" In World Construction Symposium - 2023. Ceylon Institute of Builders - Sri Lanka, 2023. http://dx.doi.org/10.31705/wcs.2023.26.

Full text
Abstract:
A rapid increase in high-rise building clusters within developing cities has led to mounting environmental and climatic issues. This is especially highlighted in Asian cities where extreme tropical climates are accentuated by ad-hoc developments, that in turn create unfavourable urban environments. Traffic emissions and air pollution, directly and indirectly, effect the Urban Heat Island (UHI) factor. Studies show that urban ventilation is a key mechanism to ameliorate UHI, reduce pollution stagnation, improve air quality, and reduce dependence on energy-consuming systems, thereby enhancing future sustainability. A research gap on the effect of the morphology of high-rise towers, and tower and podium forms as clusters on air pollution dispersion was identified. A high-rise cluster in the proposed Port City in Colombo, Sri Lanka was identified, and possible building forms were designed based on guidelines given by the local authority. Simplified three-dimensional building clusters were simulated using Ansys Fluent and a RANS k-epsilon turbulence model. Results suggest the addition of a podium has minimal impact on pollution dispersion when compared with only a tower form. Block podiums were found to concentrate pollution within the podium height, while tiered podiums pushed street pollution upwards along the face of a podium. However, more uniform dispersion was seen in tiered podiums, reducing overall pollution concentrations within the study area. Overall, as per requirement and context, it is highlighted that podium forms can be designed to create better-ventilated urban spaces with good air quality, within a high-rise high-dense environment.
APA, Harvard, Vancouver, ISO, and other styles
4

Belyaev, B. I., V. I. Shuplyak, V. V. Sikorsky, and G. F. Stelmakh. "Remote diagnostics of the plant leaf structure features: the spectropolarizational nephelometry technique." In The European Conference on Lasers and Electro-Optics. Optica Publishing Group, 1994. http://dx.doi.org/10.1364/cleo_europe.1994.cfd1.

Full text
Abstract:
It is shown that the laser and optical nephelometric measurements including the spectropolarizational ones at different angles are highly informative for non-contact plant diagnostics. Before recent time the traditional view on the polarization of plant-reflected radiation was a formation of the polarized component due to a specular reflection on the leaf surface exceptionally. Our detailed studies on the spectral and angular dependences of the reflected light polarization degree for the different plant leaves have shown that the singly and multiply scattering on intraleaf structure elements combined with chlorophyll molecular absorption is very essential for the formation of polarized light component. It is also found that the polarizational characteristics are more sensitive for the changes of plant structure as compared with the traditionally measured bidirectional reflectance factors. We have discovered and theoretically substantiated a spectral shift of a main maximum of the polarization degree angular dependence and an appearance of the additional (non-Brewster) maxima at the incident angles of 65-75°, 15-20°, 30-35° and 40-45°. The features of polarization degree angular function are resulted from single scattering processes and concerned with such factors as intraleaf water concentration, leaf's age, size, and concentration proportions of the lipid and protein components. The experimental and theoretical obtained results give the basis of optical and laser remote diagnostics of the intraleaf structure; in particular, make possible to obtain the refractive indexes of leaf structure elements, intracell particle concentrations, and particle size distribution functions. It is shown that the plant illness (in particular, bacterial cancer), ontogenetic development of plants, and ecological state of vegetation may be diagnosed from analysis of the polarization degree angular functions.
APA, Harvard, Vancouver, ISO, and other styles
5

Aguado García, Daniel, Henri Haimi, Anna Mikola, Ana Soares, and Ulf Jeppsson. "Sustainable wastewater treatment solutions for water-smart circular economy." In 2nd WDSA/CCWI Joint Conference. Editorial Universitat Politècnica de València, 2022. http://dx.doi.org/10.4995/wdsa-ccwi2022.2022.14702.

Full text
Abstract:
The Protection of aquatic water bodies and human health is a paramount objective accomplished by wastewater treatment systems. Traditionally, pollutants are managed and removed in wastewater treatment plants (WWTPs), following a paradigm in which wastewater is considered a waste. Wastewater treatment requires significant amounts of resources, such as energy and chemicals, while sludge is produced, requiring further treatment. A decade ago, a new paradigm emerged, suggesting that municipal wastewater is a source of resources, particularly reclaimed water, materials (e.g., nutrients) and energy. Many processes applicable for this new paradigm already existed, and others have been further developed (struvite-crystallization, membrane contactors, air-stripping, ionic exchange, electrodialysis, direct osmosis, etc.). Recently, resource recovery processes have been extensively developed and investigated to optimize their operation. Reclaimed water can be used for recharging aquifers, irrigation in agriculture and cooling applications. Potential risks posed by the use of reclaimed water – and of other recovered wastewater resources – must be assessed and managed during the lifecycle of the application. For example, membrane separation processes are recognised as suitable for this application to remove pathogens and particles to ensure water quality. Traditional WWTP design is based on effluent quality requirements and investment costs, with energy efficiency being only rarely considered. Larger facilities exhibit lower normalized electric consumption than smaller WWTPs, and older ones normally consume more than modern facilities (although is process dependent). For instance, in Spain it is possible to find facilities with specific electric consumptions 5-10 times higher than in modern and optimized facilities. This clearly reflects the great margin for potential energy savings. Electricity consumption at WWTPs can be reduced by improving the processes and their operation, as well as through mechanical equipment improvement. The aeration of the biological process is the major electricity consumer; thus, control strategies have been deployed to its optimization. Also, less oxygen-demanding process alternatives have been explored, like the simultaneous nitrification-denitrification operated at very low dissolved oxygen concentration. Partial nitritation and deammonification processes with low oxygen consumption per nitrogen load removed, are especially suited for treating supernatant from sludge dewatering units. However, these low energy solutions might have a downside with direct greenhouse gas GHG emissions, especially N2O. Anaerobic digestion of sludge, usually applied in large WWTPs, produces biogas that can generate both electricity and heat for local use or external use, through combined heat and power production, or liquefied biogas for external use. It is also possible to increase biogas production through co-digestion of external substrates, advanced control or sludge pre-treatment. Thermolysis processes, piloted for sewage sludge treatment, enable also waste-to-chemicals applications. There are also other possibilities for energy recovery at WWTPs, such as thermal energy via heat exchangers and heat pumps, hydropower generation using turbines, and heat from sludge incineration. Energy can be also recovered by anaerobic digestion of microalgae grown in nutrient-rich wastewater. In this paper, the transition towards sustainability and water-smart circular economy is illustrated showing how current WWTPs can be turned into Water Resource Recovery Facilities (WWRFs). The incorporation of sustainable pathways and technologies, make energy-positive facilities achievable, thus, reducing their climate impact.
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!