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Indoor air pollutants comprise both polar and non-polar volatile organic compounds (VOCs). Indoor potted plants are well known for their innate ability to improve indoor air quality (IAQ) by detoxification of indoor air pollutants. In this study, a combination of two different plant species comprising a C3 plant (Zamioculcas zamiifolia) and a crassulacean acid metabolism (CAM) plant (Sansevieria trifasciata) was used to remove polar and non-polar VOCs and minimize CO2 emission from the chamber. Z. zamiifolia and S. trifasciata, when combined, were able to remove more than 95% of pollutants within 48 h and could do so for six consecutive pollutant's exposure cycles. The CO2 concentration was reduced from 410 down to 160 ppm inside the chamber. Our results showed that using plant growth medium rather than soil had a positive effect on decreasing CO2. We also re-affirmed the role of formaldehyde dehydrogenase in the detoxification and metabolism of formaldehyde and that exposure of plants to pollutants enhances the activity of this enzyme in the shoots of both Z. zamiifolia and S. trifasciata. Overall, a mixed plant of Z. zamiifolia and S. trifasciata was more efficient at removing mixed pollutants and reducing CO2 than individual plants. [ABSTRACT FROM AUTHOR]

Climate change, characterized by rising atmospheric CO 2 levels and temperatures, poses significant challenges to global crop production. Sweet sorghum, a prominent C 4 cereal extensively grown in arid areas, emerges as a promising candidate for sustainable bioenergy production. This study investigated the responses of photosynthesis and leaf-scale water use efficiency (WUE) to varying light intensity ( I ) in sweet sorghum under different temperature and CO 2 conditions. Comparative analyses were conducted between the A n - I , g s - I , T r - I , WUE i - I , and WUE inst - I models proposed by Ye et al. and the widely utilized the non-rectangular hyperbolic (NRH) model for fitting light response curves. The Ye's models effectively replicated the light response curves of sweet sorghum, accurately capturing the diminishing intrinsic WUE (WUE i ) and instantaneous WUE (WUE inst ) trends with increasing I . The fitted maximum values of A n , g s , T r , WUE i , and WUE inst and their saturation light intensities closely matched observations, unlike the NRH model. Despite the NRH model demonstrating high R 2 values for A n - I , g s - I , and T r - I modelling, it returned the maximum values significantly deviating from observed values and failed to generate saturation light intensities. It also inadequately represented WUE responses to I , overestimating WUE. Across different leaf temperatures, A n , g s , and T r of sweet sorghum displayed comparable light response patterns. Elevated temperatures increased maximum A n , g s , and T r but consistently declined maximum WUE i and WUE inst . However, WUE inst declined more sharply due to the disproportionate transpiration increase over carbon assimilation. Critically, sweet sorghum A n saturated at current atmospheric CO 2 levels, with no significant gains under 550 μmol mol -1 . Instead, stomatal closure enhanced WUE under elevated CO 2 by coordinated g s and T r reductions rather than improved carbon assimilation. Nonetheless, this response diminished under simultaneously high temperature, suggesting intricate interplay between CO 2 and temperature in modulating plant responses. These findings provide valuable insights into photosynthetic dynamics of sweet sorghum, aiding predictions of yield and optimization of cultivation practices. Moreover, our methodology serves as a valuable reference for evaluating leaf photosynthesis and WUE dynamics in diverse plant species., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Yang, Ma, Ye, Yang, Shi, Wang, Zhou, Wang and Deng.)

The phenology has gained considerably more attention in recent times of climate change. The transition from vegetative to reproductive phases is a critical process in the life history of plants, closely tied to phenology. In an era of climate change, understanding how environmental factors affect this transition is of paramount importance. This study consisted of field surveys and a greenhouse experiment on the reproductive biology of Northern pipevine ( Aristolochia contorta Bunge). During field surveys, we investigated the environmental factors and growth characteristics of mature A. contorta , with a focus on both its vegetative and reproductive phases. In its successful flowering during the reproductive phase, A. contorta grew under the conditions of 40% relative light intensity and 24% soil moisture content, and had a vertical rhizome. In the greenhouse experiments, we examined the impact of increased CO 2 concentration on the growth and development of 10-year-old A. contorta , considering the effect of rhizome direction. Planted with a vertical rhizome direction, A. contorta exhibited sufficient growth for flowering under ambient CO 2 concentrations. In contrast, when planted with a horizontal rhizome direction, it was noted to significantly impede successful growth and flowering under elevated CO 2 concentrations. This hindered the process of flowering, highlighting the pivotal role of substantial vegetative growth in achieving successful flowering. Furthermore, we observed a higher number of underground buds and shoots under the conditions of elevated CO 2 concentration and a horizontal rhizome direction instead of flowering. Elevated CO 2 concentrations also exhibited diverse effects on mature A. contorta 's flower traits, resulting in smaller flower size, shorter longevity, and reduced stigma receptivity, and pollen viability. The study shed light on elevated CO 2 concentrations can hinder growth, potentially obstructing sexual reproduction and diminishing genetic diversity., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Park and Kim.)

Climate change has added a new dimension to the uncertainty in rice (Oryza sativa L.) yield worldwide, and Bangladesh in particular. The present study estimated the potential impacts of climate change on the yield of T. aman (Transplanted aman, BR‐22) rice variety for 12 representative districts in Bangladesh using the DSSAT 4.0 (Decision Support System for Agrotechnology Transfer) model. Available data on soil and typical crop management practice for T. aman rice were used in the simulations. The daily weather inputs required for this model were generated using the PRECIS (Predicting Regional Climate Impact Studies) model. The model predicted an average yield of T. aman cultivars for selected locations in comparison to the baseline year 2008 are +5.04, +6.06 and −32.43% for the year 2030, 2050 and 2070, respectively. Changes of monthly average temperatures were found to be primarily responsible for the reduction in rice yield. Variability in rainfall pattern over the growing period of T. aman rice also affected the yield. Furthermore, model outcomes envisaged that climate change may make rice yield more susceptible to its transplanting date, forecasting a significant change in yield as the transplanting date is shifted from beginning to the end of July. These outcomes may provide valuable insight into the potential impacts of climate change on rice yield and adequate adaptive measures to mitigate the adverse effect of future climate change in Bangladesh as well as other rice‐growing countries. [ABSTRACT FROM AUTHOR]

The study was carried out to assess the impact of climate change on potato productivity to develop adaptation strategies in Punjab, using crop growth simulation models for future climate scenarios (2030, 2050 and 2080) under representative concentration pathways (RCPs) 4.5 and 6.0. Three potato cultivars belonging to distinct maturity groups, late (Kufri Badshah), medium (Kufri Jyoti) and early (Kufri Pukhraj), were used. Simulation results showed that under RCP 4.5, increase in CO2 concentration is expected to bring an increase in productivity of Kufri Badshah, Kufri Jyoti and Kufri Pukhraj by 6.7, 7.2 and 7.1% in 2030; 10.8, 11.6 and 11.4% in 2050; and 14.0, 15.0 and 14.8% in 2080. However, the corresponding increase in temperature is likely to decline the mean productivity by 2.6, 3.8 and 3.8% in 2030; 6.5, 8.7 and 9.3% in 2050; and 14.4, 17.6 and 18.4% in 2080, for Kufri Badshah, Kufri Jyoti and Kufri Pukhraj. But, when combined influence of temperature and CO2 was considered, the productivity of potato will not be affected in 2030 and 2050 over the baseline scenario but is expected to decline in 2080 (Kufri Badshah − 1.9%, Kufri Jyoti − 4.1% and Kufri Pukhraj − 5.2%). Similarly, for RCP 6.0, increased CO2 concentration is expected to increase the mean productivity by 6.5% in 2030, 10.5% in 2050 and 19.4% in 2080. However, yield increase due to CO2 is negated by increased temperature with respective values of 2.2, 4.4 and 14.2%. However, under combined effect for RCP 6.0, productivity of potato cultivars is not likely to be affected over the baseline scenarios for 2030, 2050 and 2080. Results further revealed that by changing the dates of planting or selection of suitable cultivars, yield can increase in 2030 by 7.4% in Kufri Badshah and 7.8 and 1.5% in Kufri Pukhraj in 2050 and 2080, under RCP 4.5. Similarly, adaptation may increase mean yield up to 9.1% for Kufri Pukhraj in 2030, 9.8% for Kufri Badshah in 2050 and 8.2% for Kufri Badshah and Kufri Jyoti in 2080 under RCP 6.0. Further, with proper irrigation and nitrogen management practices, yield can be increased. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the impact of ventilation and filtration conditions on particle concentrations in an orthopedic operating room. Total particle, viable particle, and CO2 concentration were measured under three different situations, namely before air filter replacement, after air filter replacement, and in an operating room with a new air conditioning system. Before air filter replacement, the mean values of airflow, total particle concentration, and viable particle concentration were 706 m3/h, 15.0 × 106 ± 4.0 × 106 particles/m3, and 57 CFU/m3, respectively. After replacement, the airflow increased to 1954 m3/h, and total and viable particle concentrations decreased to 0.4 × 106 ± 0.2 × 106 particles/m3 and 24 CFU/m3, respectively. In the room with a new air conditioning system, the airflow was 2051 m3/h, and total and viable particle concentrations were 0.3 × 106. ± 0.1 × 106 particles/m3 and 15 CFU/m3, respectively. The CO2 levels were 663 ppm (before), 659 ppm (after), and 574 ppm (new room). The results showed that inappropriate or no maintenance of filters in an air conditioning system had significant negative effects on indoor air quality in operating rooms. Air conditioning systems operating with saturated filters can be affected by pressure drop, which can lead to a reduction in airflow, thereby resulting in an increase in the average total particle and viable particle concentrations and the risk of infection in operating rooms. However, the results showed that the CO2 concentration was not affected by the filter replacement. Article Highlights: Improper maintenance of the air filters poses negative effects in operating rooms. Particles remain inside the room with less air exchange caused by saturated filters. Change in filters produces a greater effect on air quality in operating rooms. CO2 concentration generated by the people may not be affected by the filter replacement. [ABSTRACT FROM AUTHOR]

PREMISE A CO2 control system is important for investigating how elevated CO2 affects plant growth. Our automatic CO2 monitoring and control system offers an inexpensive and flexible way to make CO2‐enriched environments. METHOD AND RESULTS Using microcontrollers paired with non‐dispersive infrared CO2 sensors, relays, and valves, we developed a low‐cost system for monitoring and controlling CO2 levels in growth chambers. CONCLUSIONS Compared with existing commercially available CO2 control systems, Arduino‐based microcontrollers offer affordable access to the data logging of CO2 levels in growth chambers, thereby reducing budget limitations for creating growth conditions with highly controlled CO2 concentrations.

Due to their slow movement and closure upon shade, partially closed stomata can be a substantial limitation to photosynthesis in variable light intensities. The abscisic acid deficient flacca mutant in tomato (Solanum lycopersicum) displays very high stomatal conductance (gs). We aimed to determine to what extent this substantially increased gs affects the rate of photosynthetic induction. Steady-state and dynamic photosynthesis characteristics were measured in flacca and wildtype leaves, by the use of simultaneous gas exchange and chlorophyll fluorometry. The steady-state response of photosynthesis to CO2, maximum quantum efficiency of photosystem II photochemistry (Fv/Fm), as well as mesophyll conductance to CO2 diffusion were not significantly different between genotypes, suggesting similar photosynthetic biochemistry, photoprotective capacity, and internal CO2 permeability. When leaves adapted to shade (50 µmol m−2 s−1) at 400 µbar CO2 partial pressure and high humidity (7 mbar leaf-to-air vapour pressure deficit, VPD) were exposed to high irradiance (1500 µmol m−2 s−1), photosynthetic induction was faster in flacca compared to wildtype leaves, and this was attributable to high initial gs in flacca (~0.6 mol m−2 s−1): in flacca, the times to reach 50 (t50) and 90% (t90) of full photosynthetic induction were 91 and 46% of wildtype values, respectively. Low humidity (15 mbar VPD) reduced gs and slowed down photosynthetic induction in the wildtype, while no change was observed in flacca; under low humidity, t50 was 63% and t90 was 36% of wildtype levels in flacca. Photosynthetic induction in low CO2 partial pressure (200 µbar) increased gs in the wildtype (but not in flacca), and revealed no differences in the rate of photosynthetic induction between genotypes. Effects of higher gs in flacca were also visible in transients of photosystem II operating efficiency and non-photochemical quenching. Our results show that at ambient CO2 partial pressure, wildtype gs is a substantial limitation to the rate of photosynthetic induction, which flacca overcomes by keeping its stomata open at all times, and it does so at the cost of reduced water use efficiency.

The Earth CO2 is constantly changing. During photosynthesis CO2 is assimilated and immobilized in the form of organic matter. In the other way around, under the action of chemical and biochemical processes, the CO2 of the organic matter is released again into the atmosphere. The current concentration of CO2 in the atmosphere is about 390 ppm. Based on information from the literature, it is possible to estimate the amount of organic matter produced from the CO2 available in the atmosphere. On the other hand, by incinerating all the plant and animal organic matter on the Earth, it is possible to estimate the amount of CO2 produced and released to the atmosphere. In order to test these hypotheses, mathematical models were developed. By the models it is possible to estimate that if all CO2 in the atmosphere is assimilated via photosynthesis, it would produce 296 Mg.ha-1 of organic matter. On the other hand, by incinerating all vegetable and animal organic matter from the Earth, excluding petroleum, coal and other carbon sources, and considering an average value of 100 Mg.ha-1 the CO2 concentration in the atmosphere would increase by 131.8 ppm. This value added to the existing 390 ppm would raise CO2 concentration to 521.8 ppm. According to the models and results presented, forests may not be as important as carbon accumulators, making the environment conducive to life on Earth, but according to literature they are essential in the formation of rainfalls and maintenance of humidity, especially in areas far from the oceans and seas.

The method of automatically controlling the CO2 concentration in a greenhouse depending on ventilation was examined in order to efficiently improve the productivity of strawberries under the weather conditions in the northern part of Kyushu in Japan. The effects of CO2 enrichment on the yields, fruit Brix, and economic value of the strawberry ‘Sagahonoka’ were investigated. In addition, in order to clarify the physiological response of ‘Sagahonoka’ to the CO2 concentration, the photosynthetic rate, translocation, and photoassimilate distribution rate were measured. It was found that maintaining the CO2 concentrations above 800 μmol mol−1 and 400 μmol mol−1 during no ventilation and ventilation, respectively, resulted in 25% increases in marketable fruit yields and a 0.2–1.2% higher fruit Brix compared to control, which was kept in 400 μmol mol−1 CO2 or above all day regardless of ventilation. Additionally, the economic value of ‘Sagahonoka’ was increased. The photosynthetic rate of ‘Sagahonoka’ increased linearly up to 800 μmol mol−1 CO2, and high CO2 concentrations affected the distribution for the primary fruit, the most significant sink. It was clarified that CO2 enrichment at 800 μmol mol−1 for ‘Sagahonoka’ was effective in increasing the photosynthetic rate and distribution of photoassimilates to fruits, and the yields of strawberries could be increased efficiently by automatically controlling the CO2 concentration depending on ventilation in a southern region of Japan.

The effects of modified atmosphere packaging (MAP) with various CO2 concentrations on the bacterial community and shelf-life of smoked chicken legs during 25 d of storage at 4 °C were evaluated herein. Four treatments were stored in pallets (PAL) and MAP under 20% (M20), 60% (M60), and 100% (M100) CO2, respectively. The results indicated that the MAP treatments provided the legs with higher redness and hardness and lower yellowness, luminance, and lipid oxidation, compared with the PAL treatment. In addition, the MAP treatments effectively inhibited the growth of viable bacteria, delayed bacterial spoilage, and extended the shelf-life of the samples. The M60 and M100 treatments had a better inhibition effect on bacteria. In terms of bacterial community, Carnobacterium, Pseudomonas, Brochothrix, and Lactococcus were the most predominant genera in the 25 d-stored MAP samples, with Carnobacterium maltaromaticum, Pseudomonas fragi, Shewanella baltica, and Lactococcus piscium being the dominant species. However, while the inhibition effects of the M60 and M100 treatments on the bacterial community at Day 25 were similar, the outer package of the M100 treatment collapsed. Overall, the M60 treatment may be a promising approach to improving the quality and extending the shelf-life of smoked chicken legs.

The 13С/12С isotopic abundances in carbon dioxide of the external environment and carbohydrates synthesized by the plant differ significantly from each other and vary depending on the growing conditions. The differences in the fraction of assimilated 13C are related apparently to the rate of photosynthetic reactions. To carry out the sample preparation for mass-spectrometric isotope analysis of carbon involved in plant life, we developed a new method of sample gasification and experimental setup. А setup provided concentrating carbon dioxide 100 times with catalytic afterburning of organic microimpurities, and the prepared sample was free from residual impurities able to interfere to a level no higher than 10^-5. The gasification method involves the plant glucose oxidation by yeast with the collecting generated carbon dioxide; the concentration of reagents were matched for it. The collected CO2 was ready for isotopic measurements and the level of residual impurities able to interfere was less than 10^-5. The developed sample preparation technique has been used to study the influence of spectral characteristics of the light medium on the exchange of carbon isotopes between atmospheric CO2 and the plant carbon pool.

This article continues the research presented at the last year conference by Kapalo et al. (2017) in the article "Renovation of the building and its impact on air pollution". The main purpose of this study is to quantify the amount of carbon dioxide produced inside an apartment building with 90 occupants, before and after the thermal rehabilitation process. As expected, the improving actions on building thermal insulation had a positive effect on energy consumption and, as a consequence, the CO2 footprint of the building decreased significantly. After changing the old wooden windows with new tight ones and after using a heat recovery air handling unit, the values of CO2 production were reduced by 48%, as resulting from the conversion of energy savings due to heating of the building. After applying the thermal insulation on building envelope, the equivalent CO2 releases of the apartment building were reduced to a final value of 40% compared to the CO2 footprint before the building thermal rehabilitation.

Abstract Horticultural crop production and changes in physiological aspects during the growing season may be affected by climate change factors (CC), which include increased temperature and the associated doubling or tripling of atmospheric CO2 concentrations. However, the potential effects are complex and many parameters might impact on the observed effects. To evaluate the effects of CC, the growth, yield, fruit characteristics, photosynthetic traits, and morphological characteristics of hot peppers were investigated. The hot peppers were grown under two CC scenarios, with the Representative Concentration Pathway (RCP) of 4.5 (Temp.; +3.4°C, CO2 conc.; 540 μmol/mol, Precipitation +17.3%) and RCP 8.5 (Temp.; +6.0°C and CO2 conc.; 940 μmol/mol, Precipitation +20.3%), respectively, using extreme weather simulators. This was compared with existing weather conditions occurring in Jeonju, South Korea in terms of air temperature, relative humidity, radiation, and precipitation. Overall, the plant height showed the highest under moderate CC conditions (RCP 4.5) among all the treatments tested. The number of leaves in the RCP 8.5 condition showed 7,739/plants, which was 2.2 times higher than that of the control. In addition, fruit shape was shortened and percentage dry matter was also the highest. The yield of hot pepper in the CC RCP 4.5 and 8.5 conditions were decreased by 21.5% and 89.2% when compared with that of the control, respectively. The days to harvest in the condition of CC scenarios were shortened from 5 to 13 compared with that of control, predominantly due to the increased air temperature. The results indicated that the severe RCP CC scenarios made reduction in the yields and negative affection on the fruit qualities. Overall, hot pepper was tolerant of mild CC scenarios of temperature × CO2 but was significantly affected by more extreme CC interacting parameter concentrations (or similar).

Concepts of semi-closed greenhouses can be used to save energy, whereas their technical equipment often causes a decrease in the light received by the plants. Nevertheless, higher yields are achieved, which are presumably triggered by a higher CO2 concentration in the greenhouse and associated higher photosynthesis because of the technical cooling and the longer period of closed ventilation. Therefore, we examined the effects of photosynthetic photon flux density (PPFD) and CO2 concentration on plant photosynthesis and transpiration in tomato using a multiple cuvette gas exchange system. In a growth chamber experiment, we demonstrated that a light-mediated reduction in photosynthesis can be compensated or even overcompensated for by rising CO2 concentration. Increasing the CO2 concentration from 400 to 1000 µmol mol−1 within the PPFD range from 303 to 653 µmol m−2 s−1 resulted in an increase in net photosynthesis of 51%, a decrease in transpiration of 5 to 8%, and an increase in photosynthetic water use efficiency of 60%. Estimations showed that light reductions of 10% can be compensated for via increasing the CO2 concentration by about 100 µmol mol−1 and overcompensated for by about 40% if CO2 concentration is kept at 1000 instead of 400 µmol mol−1.

Research towards understanding the relationship between maintaining thermal comfort and energy efficiency in the public utility buildings was undertaken among 323 1st year students during class hours. Questionnaires surveys and measurements of indoor conditions were performed. The article identified students’ sensations and perceptions concerning indoor conditions. Temperature, relative humidity, air velocity and CO2 concentration measured to assess room conditions showed that the auditorium had almost comfortable conditions according to the literature guidelines. The indices used to assess students’ perceptions were: Thermal Sensation Vote (TSV), Thermal Preference Vote (TPV), Air Freshness Sensation Vote (AfSV), Air Movement Preference Vote (AmPV), and Relative Humidity Preference Vote (RHPV). The interpretation of these indicators showed that while the students’ requests for temperature changes and increased air movement are adequate for the air conditions in the room, the evaluation of stuffiness and requests for changes in humidity levels are surprising. Striving uncritically to meet the desired room parameters, according to the users votes, can lead to deterioration of the air and not only the increase in energy consumption but even waste it. Better understanding of users’ preferences and behaviour and further application of this knowledge indirectly aim at increasing energy efficiency in buildings.

There are currently trends in the world to transfer and adapt traditional solutions to contemporary needs. This applies, inter alia, to mobile shelters used by nomadic peoples. The article is devoted to the research on the quality of internal air in the yurt and the possibilities of its adaptation to high contemporary quality and environmental requirements, while maintaining its characteristic sustainable values. The tested traditional Mongolian yurt was moved from the dry and cold climate of the Asian steppe to the temperate climate of Central Europe and has been significantly modified. The outer shell materials have been changed, replacing natural materials with modern tight insulating foils. The wood-fired stove has been replaced with an electric heater and the roof opening has been firmly closed. All of these modifications resulted in far-reaching changes in the quality of the internal environment in the yurt. The conducted measurements and simulations of CO2 concentration in the modified yurt proved that the efficiency of ventilation system is not sufficient and that the air quality is very poor (even for a single user). In the case of a larger number of users, the concentration of CO2 has already reached a level that was dangerous to health. The simplest method of improving the air quality in the yurt is its careful unsealing to the required level. Striving for a low energy demand, however, would require a completely different approach (for example, in the form of forced ventilation with a heat recovery unit, ultimately powered with a PV array). Such a solution is very different from the traditional yurt model but is close to modern expectations and environmental requirements.

PREMISE: A CO2 control system is important for investigating how elevated CO2 affects plant growth. Our automatic CO2 monitoring and control system offers an inexpensive and flexible way to make CO2‐enriched environments. METHOD AND RESULTS: Using microcontrollers paired with non‐dispersive infrared CO2 sensors, relays, and valves, we developed a low‐cost system for monitoring and controlling CO2 levels in growth chambers. CONCLUSIONS: Compared with existing commercially available CO2 control systems, Arduino‐based microcontrollers offer affordable access to the data logging of CO2 levels in growth chambers, thereby reducing budget limitations for creating growth conditions with highly controlled CO2 concentrations. [ABSTRACT FROM AUTHOR]

The energy demand increases along with demographic and development growth. India is the second-most populous country in the world and most of its population needs more energy as its human and energy development indices are rather low. So, the country depends on cheaper sources of energy which have ample effects on the environment. Many energy sources are polluting, but solar energy is pollution-free and its availability is abundant with zero cost. Solar Photo Voltaic (PV) technology is the best technology to harness electricity. The effect of varying environmental factors regulates the performance factors of this technology. Its efficiency mainly depends on the concentration of greenhouse gases (GHGs), ambient temperature, module temperature, incoming solar radiation intensity, and PV material composition. To understand the behavior of solar panels on maximum power point under various GHGs concentrations, three experiments were conducted. One in normal atmospheric CO2 concentration and two in higher CO2 concentration chambers. [ABSTRACT FROM AUTHOR]

• Potential use of fluidized bed bioreactor to grow microalgae on polyurethane foam. • Optimum light intensity and CO 2 interaction to spur attached microalgal growth. • N-rich real wastewater impact on mechanism of microalgal attachment formations. • Consequential reusability of fluidized bed on microalgae-based biodiesel quality. Impoverishing nutrients from wastewater via assimilation into microalgal biomass has gained footprint in bioremediation technologies. To ease the harvesting of mature microalgal biomass from effluent, this study proposed the employment of fluidized bed bioreactor to grow attached microalgal biomass onto polyurethane foam support material while bioremediating the N-rich real wastewater from chemical fertilizer manufacturing industry. The complete removals of all nitrogen species (NH 4 +-N, NO 2 −-N and NO 3 −-N) together with COD and total phosphorus were achieved at the optimum light intensity and CO 2 concentration of 216 μmol/m2 s and 9.1 %, respectively, giving rise to the attached microalgal biomass productivity of 0.094 g/L/day. These performances were also found maintaining for at least 4 cycles of reiterative uses of spent polyurethane foam support material in similar fluidized bed bioreactor setup condition with every cycle being introduced with fresh N-rich real wastewater. The mechanism of attachment formations study predicted that the polysaccharides and proteins from microalgal extracellular polymeric substances had bridged the cells onto polyurethane foam support material during the initial colonization prior to populating and growing to cover the surfaces of support material. For biodiesel production, the extracted neutral lipid content of attached microalgal biomass was found to be four times higher than the suspended growth culture. From the transesterification process, about 97 %–98 % of attached microalgal lipid could be converted into fatty acid methyl esters (FAMEs) mixture. Interestingly, the degree of saturated fatty acids (SFA) in FAMEs was recorded increasing with the increase of cycles of reusing spent polyurethane foam support material. The presence of more SFA in FAMEs could overall enhance the oxidative stability and contribute to higher cetane number of produced biodiesel from facilely harvested attached microalgal biomass. [ABSTRACT FROM AUTHOR]

The unicellular green alga Haematococcus pluvialis is considered the optimal natural source of astaxanthin, a strong antioxidant in nature. In the present study, transcriptome and metabolic profiling of H. pluvialis under 0.16% and 0.04% CO2 levels were performed to explore the underlying mechanism by which CO2 affects growth at the vegetative stage of this alga. Approximately 1665 differentially expressed unigenes were screened in response to different CO2 conditions by transcriptome analysis. The genes related to photosynthesis, the tricarboxylic acid (TCA) cycle, glycolysis, pentose phosphate pathway, and nitrogen metabolism, were mostly up-regulated by 0.16% CO2. A total of 36 differential metabolites were identified in metabolic profiling, of them, citric acid and ribose were accumulated; however, 12 common amino acids and stress-resistant related substrates such as ornithine and putrescine were decreased at 0.16% CO2 level. Combing the results of the algal growth, the elevated CO2 promoted photosynthesis, and carbon utilization including TCA cycle and glycolysis, together with the stimulated nitrogen metabolism, protein synthesis, and energy metabolism, which resulted in rapid growth of H. pluvialis. [ABSTRACT FROM AUTHOR]

Due to their slow movement and closure upon shade, partially closed stomata can be a substantial limitation to photosynthesis in variable light intensities. The abscisic acid deficient flacca mutant in tomato (Solanum lycopersicum) displays very high stomatal conductance (gs). We aimed to determine to what extent this substantially increased gs affects the rate of photosynthetic induction. Steady-state and dynamic photosynthesis characteristics were measured in flacca and wildtype leaves, by the use of simultaneous gas exchange and chlorophyll fluorometry. The steady-state response of photosynthesis to CO2, maximum quantum efficiency of photosystem II photochemistry (Fv/Fm), as well as mesophyll conductance to CO2 diffusion were not significantly different between genotypes, suggesting similar photosynthetic biochemistry, photoprotective capacity, and internal CO2 permeability. When leaves adapted to shade (50 µmol m−2 s−1) at 400 µbar CO2 partial pressure and high humidity (7 mbar leaf-to-air vapour pressure deficit, VPD) were exposed to high irradiance (1500 µmol m−2 s−1), photosynthetic induction was faster in flacca compared to wildtype leaves, and this was attributable to high initial gs in flacca (~0.6 mol m−2 s−1): in flacca , the times to reach 50 (t50) and 90% (t90) of full photosynthetic induction were 91 and 46% of wildtype values, respectively. Low humidity (15 mbar VPD) reduced gs and slowed down photosynthetic induction in the wildtype, while no change was observed in flacca ; under low humidity, t50 was 63% and t90 was 36% of wildtype levels in flacca. Photosynthetic induction in low CO2 partial pressure (200 µbar) increased gs in the wildtype (but not in flacca), and revealed no differences in the rate of photosynthetic induction between genotypes. Effects of higher gs in flacca were also visible in transients of photosystem II operating efficiency and non-photochemical quenching. Our results show that at ambient CO2 partial pressure, wildtype gs is a substantial limitation to the rate of photosynthetic induction, which flacca overcomes by keeping its stomata open at all times, and it does so at the cost of reduced water use efficiency. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper explores the effects of three types of admixture treatments: (1) monospecific (M: European beech surrounded by six European beech seedlings), (2) single-admixture (S: European beech surrounded by six Norway spruce seedlings), and (3) group-admixture (G: European beech surrounded by three Norway spruce and three European beech seedlings), and two different CO2 concentrations ([CO2]): ambient [AMBCO2, 385 μmol (CO2) mol−1] and elevated [ELECO2, 770 μmol (CO2) mol−1] on the stem diameter increment (DI), based on a 7-year monitoring of the diameter growth of European beech (Fagus sylvatica L.) seedlings. Furthermore, to improve our understanding of the influence of climatic variables, we assessed the effects of precipitation and temperature on radial growth. After 7 years' experience (irrespective of admixture treatment), our data were not able to confirm the effect of elevated CO2 on the diameter growth (p value = 0.35), but the result was changed when the effect of elevated CO2 was considered under the different types of admixture. Elevated CO2 along with single-admixture increased the diameter increment significantly (p value = 0.001). In contrast, we characterized a significant effect of AMBCO2 × G interaction on DI (p value = 0.002). But DI was unaffected by elevated CO2 in M (p value = 0.77). In both [CO2], inter-specific competition with spruce resulted in the highest radial growth. The inter-specific interaction was most pronounced in the lower proportion with spruce (S) in ELECO2, while in ambient CO2, the higher proportion with spruce (G) had the greatest effect on the radial growth. With respect to the climatic factors, our observations showed that temperature had a stronger influence than precipitation in ELECO2, but in AMBCO2, precipitation had the strongest effect on the radial growth as indicated by the statistically significant correlation between climatic variables and radial growth. Overall, our result suggested that seedlings growth was more under the control of climate and edaphic factors than dependent on tree species diversity and CO2 concentrations. [ABSTRACT FROM AUTHOR]

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

Healthcare facilities provide a cure from the ailment while maintaining a clean environment. A high indoor environmental quality (IEQ) can improve the recovery process and create a pleasant working environment, while a poor IEQ causes nosocomial diseases that are harmful to the patients as well as the hospital staff. To assess the state of IEQ in selected local hospitals, the current study investigates critical IEQ parameters. Based on a detailed literature synthesis, three parameters are selected (temperature, relative humidity, and CO2) for IEQ assessment in four local hospitals. Four different locations (emergency room, OT, ICU, and medical ward) in each hospital are considered with respect to the existing heating, ventilation, and air conditioning (HVAC) system. Data is recorded on a 5-min interval for 6 days uninterrupted and the mean hourly value for each location is calculated for 24 hours. Statistical analysis is performed to compare the day- and night-time IEQ trends. A significant difference is found in the day- and night-time observations for OTs, while random trends are noticed in emergency areas. The results show that occupancy rate, ambient thermal conditions, type of HVAC system, and building orientation are vital drivers of IEQ. In conclusion, design and retrofitting recommendations are provided. [ABSTRACT FROM AUTHOR]

Optimization of an amine‐based method is vital to ensure product quality, equipment safety, and system efficiency. Here, the effectiveness of amine concentration and circulation rate is evaluated for a diglycolamine (DGA)‐based facility. The performance is measured using the concentration of carbon dioxide in the treated gas and the net acid gas loading of the amine solution. Both amine concentration and circulation rate were observed to affect the system efficiency. An optimal operating range was identified for the gas plant studied established on the performance criteria. The analysis is based on a proprietary mass transfer‐based process simulator of an amine‐based acid gas treating facility and field data. [ABSTRACT FROM AUTHOR]

• The optimal control of environmental conditions is an effective way for improving plant growth, quality, and input resources use efficiency. • Light is the main source of energy required for photosynthesis and many other physiological processes related to plant growth. • Light quality influences plant growth and development more than light intensity and photoperiod. • Light spectrum for plant response ranges from the UV (280–400 nm) to the far-red (700–800 nm) regions. • More studies are still needed, taking into account integrative environmental control, input resources efficiency, and economic analysis. Lettuce is one of the most popular leafy vegetables produced in controlled environments with artificial lighting (CEALs). Optimal control of environmental conditions can be used to facilitate the improvement of lettuce plant growth and light use efficiency. This article reviews and discusses the effects of light, air velocity, temperature, relative air humidity, and CO 2 concentration on the growth and development of lettuce plants in a CEAL. A review of previous studies revealed that light intensity in the range between 200–250 µmol m−2 s−1 with a photoperiod of 16–18 h using red and blue LEDs, with a ratio between 5 and20% for the blue light are optimal to improve lettuce plant growth and light use efficiency. The optimal light quality can also be achieved by using supplemental white or green LEDs, far-red light, and UV-A radiation. Air velocity in the range between 0.3 and 0.7 m s−1 enhances the photosynthetic rate, transpiration rate, and gas diffusion through the boundary layer of the leaf and prevents the occurrence of tipburn. The air temperature of 22–25 °C during the light periods was reported as optimal to enhance CO 2 uptake and consequently improve lettuce growth. Relative air humidity in the range between 70 and 80% promotes vegetative growth and reduces water stress by causing the stomata to close. High CO 2 concentrations increased photosynthetic rate but also decreased CO 2 utilization efficiency. Therefore, CO 2 concentration in the range between 1000 and 1500 µmol mol−1 is optimal for high growth rate, productivity, and CO 2 utilization efficiency. Most of the previous studies have focused on the effect of light intensity, quality, and duration on the growth and development of lettuce plants under artificial light, with limited information about the interactions of all environmental conditions. This review will be useful for growers, researchers, and designers in the field of plant production in CEALs. [ABSTRACT FROM AUTHOR]

Temperature and CO2 are the two most important climate parameters that affect crop yield directly. In this study, the impact of these two parameters on the productivity of peanut and rice under the sub-humid and sub-tropical condition of Eastern India were assessed using experimental data and the DSSAT v4.5 CROPGRO-Peanut and CERES-Rice model. Experimental results of peanut and rice with four sowing dates of each were used as the baseline scenarios. The future weather data from the CSIRO-Mk3–6.0 model for RCP 4.5 and 8.5 was used to the peanut and rice crop model to simulate the yield using future weather data for the periods 2020, 2050, and 2080, and change in yield was compared with the baseline (1980–2013) at Kharagpur, West Bengal, India. The results reveal that rising temperature has negative effect on the growth and developmental phases of crop, and it brings early flowering. Concurrently, increase in temperature causes reduction of crop yield due to pollen sterility and poor pollen growth during reproductive growth stage. The CO2 concentrations used in the model, as projected by IPCC, were 390, 420, 530, and 650 ppm for the years 1980–2013 (baseline), 2020, 2050, and 2080, respectively. However, simulation was made using the model for percent change in mean temperature of 3.36 °C for 2020, 7.59 °C for 2050, and 10.4 °C for 2080. The model simulation reveals that elevated CO2 concentration of 420, 530 and 650 ppm showed gradual increase in the grain yield and biomass yield with shifting in sowing dates for peanut crop. On the other hand, for rice crop, though the crop yield increases gradually, the total biomass yield would reduce in future climate change scenario. [ABSTRACT FROM AUTHOR]

• The microstructural and mechanical performances of dry-mix cement paste in view of CO 2 concentration and further water curing was investigated in detail. • The compressive strength and microstructure at 2 h (immediately after carbonation) and 1, 3 and 7 days with further water curing was explored. • The hydrated and carbonated products was analyzed by XRD and TGA. The microstructure change of C-S-H and calcium carbonate was further analyzed by NMR and SEM. Early-age carbonation can make a significant difference in the formation of hydration products in cement-based materials and alter the microstructural and mechanical performances. To understand in detail the impacts and their contribution to cement hydration, dry-mix cement pastes were exposed to instant carbonation with 0.04 %, 1%, 3%, 10 %, 20 % CO 2 concentrations for 2 h prior to further water curing. By increasing the CO 2 concentration, an increment in strength gain of samples at 2 h (right after early carbonation) as well as being prolonged by water curing at 1, 3, 7 days was noticed. This agrees with TGA and XRD results, demonstrating that the increases in CO 2 concentration resulted in a higher carbonation reaction and hydration degree. 29Si NMR results also indicate that the higher the CO 2 concentration the lower the calcium to silica ratio (Ca/Si); thus, there is a higher degree of polymerization to promote early hydration. It can be concluded that early carbonation of 2 h in particular with a high CO 2 concentration can be beneficial for further cement hydration due to the consumption of calcium hydroxide (CH) and nuclei site effect of calcite crystals, resulting in better microstructural properties and mechanical performance. [ABSTRACT FROM AUTHOR]

In the construction process of modern buildings, the aim is to achieve maximum comfort within minimum energy consumption. One of the ways to achieve this requirement is the accurate determination of the volumetric flow rate of fresh air, necessary to ensure the required indoor air quality. This study begins with the experimental determination of carbon dioxide (CO2) concentration in an office room with one occupant performing three types of activities with different levels of physical intensities. Based on these measurements, a methodology for the precise determination of the volumetric air flow rate is presented. This method was compared with another one that takes into account body parameters and is considered in this study as the most accurate. The required outdoor air flow rate for the experimental room was also determined based on the present legislations of five different countries. Comparing all the studied methods and considering as refence the method based on body parameters, it was found that the accuracy of the values is influenced by the physical intensity of the activity and that most methods generally underestimate the amount of required fresh air. [ABSTRACT FROM AUTHOR]

A multifactorial field experiment in an open-top chamber facility at the experimental station Domaninek was conducted in 2014 to understand the potential effects of climate change factors on the malting quality of spring barley and to evaluate the interactions of these factors with nitrogen nutrition. The results showed a major effect of nitrogen nutrition on malting quality. Nitrogen increased the protein content and impaired the key malting quality parameters such as a relative extract or Kolbach index. Elevated CO2 concentration had a generally positive effect on malting quality and alleviated the negative impact of nitrogen nutrition particularly. Reduced water availability had only a minor impact on malting quality; however, these effects were predominantly positive. [ABSTRACT FROM AUTHOR]

Dark, that is, nonphototrophic, microbial CO2 fixation occurs in a large range of soils. However, it is still not known whether dark microbial CO2 fixation substantially contributes to the C balance of soils and what factors control this process. Therefore, the objective of this study was to quantitate dark microbial CO2 fixation in temperate forest soils, to determine the relationship between the soil CO2 concentration and dark microbial CO2 fixation, and to estimate the relative contribution of different microbial groups to dark CO2 fixation. For this purpose, we conducted a 13C‐CO2 labeling experiment. We found that the rates of dark microbial CO2 fixation were positively correlated with the CO2 concentration in all soils. Dark microbial CO2 fixation amounted to up to 320 µg C kg−1 soil day−1 in the Ah horizon. The fixation rates were 2.8–8.9 times higher in the Ah horizon than in the Bw1 horizon. Although the rates of dark microbial fixation were small compared to the respiration rate (1.2%–3.9% of the respiration rate), our findings suggest that organic matter formed by microorganisms from CO2 contributes to the soil organic matter pool, especially given that microbial detritus is more stable in soil than plant detritus. Phospholipid fatty acid analyses indicated that CO2 was mostly fixed by gram‐positive bacteria, and not by fungi. In conclusion, our study shows that the dark microbial CO2 fixation rate in temperate forest soils increases in periods of high CO2 concentrations, that dark microbial CO2 fixation is mostly accomplished by gram‐positive bacteria, and that dark microbial CO2 fixation contributes to the formation of soil organic matter. [ABSTRACT FROM AUTHOR]

• A study combined experiment and numerical analysis was firstly performed to improve the ventilation system in a Mine refuge chamber (MRC). • A new analytical model of fifty-person MRC is proposed. • Average CO 2 concentration can be controlled below 0.5 % by ventilation of 0.1 m3/min per person. • Air inlets arranged on both sides or top and air outflows arranged on both ends of the MRC are recommended. • A quantitative relationship between CO 2 concentration and ventilation rate, CO 2 release rate was proposed. A combined experimental and numerical study was performed to improve the performance of the ventilation system in a mine refuge chamber (MRC). In the experiment, CO 2 cylinders and dispersion pipes were used to simulate the CO 2 release of 50 people, and 0.1 L/min per person of fresh air was provided by an air compressor. A new analytical model for a 50-person MRC was proposed and validated against the experimental data. Sensitivity analysis was carried out to investigate the effects of several control factors. The results indicated the following: (1) The ventilation system layout has a significant influence on the CO 2 concentration distribution in an MRC, while the uniformity of the CO 2 concentration distribution in the MRC may not be effective with increased number of air inlets. (2) Under a well-arranged ventilation system in the 50-person MRC, the average CO 2 concentration can be controlled at less than 0.5 % with a ventilation rate of 0.1 m3/min per person, and less than 0.2 % with a ventilation rate of 0.3 m3/min per person. (3) A quantitative correlation exists between the CO 2 concentration and ventilation volume rate, as well as the CO 2 release rate, for an MRC under a well-arranged ventilation system. [ABSTRACT FROM AUTHOR]

Elevated atmospheric CO2 has resulted in climate warming since the end of 21th century due to its greenhouse effect. Global warming coupled with elevated CO2 concentration could have a drastic consequence for physiological processes of maize (Zea mays L.), a stable plant with C4 photosynthetic pathway. Understanding photosynthetic processes, transpiration and water use efficiency of maize under different CO2 concentration and temperature would shed insight into how maize would respond to climate change. Using growing chambers, we measured growth, photosynthesis and water use efficiency of maize grown in six chambers with day/night temperature controlled at 25/19°Cto 37/31°C at ambient CO2 concentration (400 μmol/mol) and elevated CO2 concentration (800 μmol/mol), respectively. Other factors in the chambers were kept the same, with the relative humidity being 55% - 65%, photosynthetic photon flux density (PPFD) being 1000 μmol/m2·s, and daily 12 h photoperiod for 60 days. In each treatment, we measured the net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), leaf water use efficiency (WUE), using a portable photosynthesis system (Licor-6400). In addition, we also measured plant biomass, leaf area, total carbon and nitrogen contents, and soluble sugars (glucose, fructose, and sucrose) in the plant. The results showed that the temperature had a dramatic impact on growth of the maize, whereas the biomass and height of the plants grown under the elevated CO2 were almost the same as those grown under the ambient CO2. It was also found that the response of Pn to temperature was not affected by CO2 when temperature was 25/19°C and 37/31°C, while the elevated CO2 increased Pn by 16.4% (P<0.05) when temperature was risen to 37/31°C, suggesting that CO2 elevation might have improved the tolerance of maize to thermal stress thereby reducing thermal damage to maize leaves. Warming significantly increased soluble sugars concentrations, especially the concentration of fructose, when temperature was risen from 25/19°C to 31/25°C, but followed by a decline when temperature was further risen to 37/31°C, alluding that thermal stress might have suppressed the photosynthesis leading to a decrease in soluble sugars content of the leaves. At temperature 37/31°C, the elevated CO2 boosted soluble sugars in the leaves due to the increased photosynthetic rates, while a further temperature rise reduced the water use efficiency (WUE) of the leaves. The elevated CO2 enhanced WUE by ameliorating the adverse effect of temperature on WUE, but under different mechanisms. When temperature was 25/19°C and 31/25°C, the elevated CO2 improved WUE due to the reduction in Tr, while when the temperature was 37/25°C, the elevated CO2 alleviated the adverse effect of temperature on photosynthesis to improve WUE. The results suggested that climate warming may reduce Pn and WUE of maize, but the associated elevated atmospheric CO2 could alleviate the adverse impact of the warming on Pnthere by improving the WUE. These findings are helpful for adequately assessing the consequence of climate change for growth and water use efficiency of maize and have important implication for ecosystem management in response to climate change. [ABSTRACT FROM AUTHOR]

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

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

The Earth CO2 is constantly changing. During photosynthesis CO2 is assimilated and immobilized in the form of organic matter. In the other way around, under the action of chemical and biochemical processes, the CO2 of the organic matter is released again into the atmosphere. The current concentration of CO2 in the atmosphere is about 390 ppm. Based on information from the literature, it is possible to estimate the amount of organic matter produced from the CO2 available in the atmosphere. On the other hand, by incinerating all the plant and animal organic matter on the Earth, it is possible to estimate the amount of CO2 produced and released to the atmosphere. In order to test these hypotheses, mathematical models were developed. By the models it is possible to estimate that if all CO2 in the atmosphere is assimilated via photosynthesis, it would produce 296 Mg.ha-1 of organic matter. On the other hand, by incinerating all vegetable and animal organic matter from the Earth, excluding petroleum, coal and other carbon sources, and considering an average value of 100 Mg.ha-1 ___ the CO2 concentration in the atmosphere would increase by 131.8 ppm. This value added to the exis-47 ting 390 ppm would raise CO2 concentration to 521.8 ppm. According to the models and results presented, forests may not be as important as carbon accumulators, making the environment conducive to life on Earth, but according to literature they are essential in the formation of rainfalls and maintenance of humidity, especially in areas far from the oceans and seas. [ABSTRACT FROM AUTHOR]

Many old public buildings in Central and Eastern Europe are characterized by low energy efficiency and often lack of mechanical ventilation. The general trends are aimed to improve the energy efficiency of the building sector and to provide comfort conditions. The indoor air quality can be determined based on the CO2 concentrations. In the article, a complex approach to the definition and analysis of data on the indoor CO2 concentration and the air exchange rate in educational institutions at natural air exchange and in the absence of mechanical air circulation was implemented. Educational institutions in Kyiv have been considered. The study of the CO2 concentration of indoor and outdoor air of three typical schools of mass development in the 80 s, as well as the training building of Igor Sikorsky KPI, was carried out. Experimental determination of the background CO2 concentration during the day next to the considered objects showed that the background concentration of CO2 is in the range of 400-420 ppm. Measurements of the CO2 concentration distribution were carried out after classes throughout the classroom area, according to which the difference between the values at the level of the working area was 30...180 ppm. It was found that the concentration of CO2 varies during classes between 700-1100 ppm. During the break, the CO2 concentration decreases to 500-1000 ppm, depending on the type of ventilation. Experimental data on the dynamics of changes in the indoor CO2 concentration are used to determine the air exchange rate based on balances of air flows and CO2. It is shown that the number of present persons influences the indoor CO2 concentration more significantly than the air exchange rate. On the example of an experimental study of the CO2 concentration in the classrooms for high school students it was found that the air exchange rate during the classes is in the range of 0.4...0.75 h-1. During breaks the air exchange rate increases to 2.9-3.5 h-1. For the range considered, the weighted average air exchange rate is 0.8 h-1, and even with forced airing, the air exchange rate is insufficient to ensure acceptable CO2 concentration. For the training building of Igor Sikorsky KPI a field experiment was carried out to determine the dynamics of changes in CO2 concentration in time and on the basis of it the air exchange rates for representative classrooms were determined. The concentration of CO2 ranged from 500 to 2000 ppm and increases by 350-850 ppm depending on the use and location of classrooms. Based on experimental data, the air exchange rate for the training building of the education institution is in the range of 0.35-0.7 h-1. During the periods of airing the air exchange may increase by 0.45 h-1, but this does not allow reaching the standard value. When analyzing the obtained results, simulation models of natural air exchange of the examined classrooms were used on the basis of the improved ASHRAE method. The natural air exchange rate based on simulations is in the -0.8...0.5 h-1 range. Negative values are explained by exfiltration, which is typical for the upper floors. Not only the comfort and condition of the building envelope, but also the total energy consumption of the building depend on the actual level of air exchange rate. In the total energy balance the ventilation component is 30-60%. Further use of the obtained results can be connected with monitoring of the actual level of air exchange rate and its consideration during complex modernization or implementation of the ventilation systems with heat recovery in the premises of educational institutions. [ABSTRACT FROM AUTHOR]

The article presents the results of studies of the influence of land transformation of Ukraine on the formation of CO2 emissions and assimilation and the potential of reducing its concentration in the atmosphere. The reports of Ukraine to the United Nations Framework Convention on Climate Change (UNFCCC) from 1990 to 2015 were used. Based on the data of correlation-regression analysis, it is established that the impact on CO2 emission and assimilation is caused by the transformation of lands: into forests (by 83.9%), wetlands (by 54.3%), settlements (by 38.7%). According to the results of the research, three levels of significance of the environmental impact of land transformation on the formation of CO2 emissions are identified. Forests and wetlands are included in the 1st, arable lands and settlements in the second, other lands and pastures by the third. Of the 75.5% of the total change in CO2 volume, 15.3% is explained by the variation in the change in arable land; 6.6% - by changing the areas of land converted into pastures; 41.1% by the change in the area of land transformed to settlements; 6.2% by changing the area of land transformed to other land; 6.2% is explained by changes in air temperature. The data obtained showed that a change of the area of transformed lands by 1% for individual lands (except forests and wetlands), provided that the established transformation trends are maintained, will lead to an increase (or decrease) of CO2 emissions: for arable land - by 22.5%; for pastures - by 23.7%; for settlements - by 38.7%; for other lands - by 23.8%. A change in air temperature of 1% (0.0879 t ˚C), if the trends of transformation are maintained, will result in a 34.8% change in CO2 emissions. It is proved that air temperature is a determining component that simultaneously affects all types of land and the formation of CO2 emissions. This factor is sufficiently influential and poorly controlled and can dramatically change the environmental situation. [ABSTRACT FROM AUTHOR]

Increasing air temperature and atmospheric CO2 levels may affect the distribution of invasive species. Whereas there is wide knowledge on the effect of global change on temperate species, responses of tropical invasive species to these two global change drivers are largely unknown. We conducted a greenhouse experiment on Terminalia catappa L. (Combretaceae), an invasive tree species on Brazilian coastal areas, to evaluate the effects of increased air temperature and CO2 concentration on seed germination and seedling growth on the island of Santa Catarina (Florianópolis, Brazil). Seeds of the invasive tree were subjected to two temperature levels (ambient and +1.6 °C) and two CO2 levels (ambient and ~650 ppmv) with a factorial design. Increased temperature enhanced germination rate and shortened germination time of T. catappa seeds. It also increased plant height, number of leaves and above‐ground biomass. By contrast, increased atmospheric CO2 concentration had no significant effects, and the interaction between temperature and CO2 concentration did not affect any of the measured traits. Terminalia catappa adapts to a relatively broad range of environmental conditions, being able to tolerate cooler temperatures in its invasive range. As T. catappa is native to tropical areas, global warming might favour its establishment along the coast of subtropical South America, while increased CO2 levels seem not to have significant effects on seed germination or seedling growth. [ABSTRACT FROM AUTHOR]