Environmental Controls Research Articles

Regulation of Precipitation on Soil Dissolved Organic Matter in Perturbed Mangrove Ecosystems

Carbon sinks in mangrove soils play a critical role in climate change mitigation globally. Soil dissolved organic matter (DOM) is a major form of labile organic matter and influences carbon cycling in wetland ecosystems. However, the factors regulating DOM pools in mangrove soils on a regional scale are not well understood. Here, we used a novel approach to assess soil DOM dynamics and its environmental drivers in mangrove wetlands on a national scale in China. Soil samples were collected from 43 sampling sites and distributed in mangroves across the coastline of China. DOM extracted from mangrove soils was characterized by fluorescence spectroscopy. We estimated that dissolved organic carbon (DOC) content ranged from 0.20 ± 0.02 g/kg to 3.85 ± 0.09 g/kg and nationally averaged 0.73 ± 0.07 g/kg in mangrove soils. Soil DOM was composed of humic-like substances, including humic acid-like (53.46 ± 8.74%) and fulvic acid-like (46.54 ± 8.74%). DOM pools in mangrove soils were identified to be perturbed by terrestrial inputs. Besides, the coupling interactions of environmental controls on the soil DOM pool were validated by establishing the structural equation modeling (SEM). We found that precipitation is the most important driver, which controlled directly the inputs and outputs of DOM pools. It also indirectly influenced DOM pools by regulating soil parameters through the cascade reactions. Cu, salinity, and clay are key mediators among soil parameters for precipitation affecting DOM pools. Precipitation influences soil DOC negatively and CDOM and FDOM positively markedly. The results provide novel insights into the labile carbon pool in mangrove soils and are beneficial for improving the assessment frameworks in the blue carbon ecosystems.

SliceChip: a benchtop fluidic platform for organotypic culture and serial assessment of human and rodent pancreatic slices.

Enzymatically isolated pancreatic islets are the most commonly used ex vivo testbeds for diabetes research. Recently, precision-cut living slices of human pancreas are emerging as an exciting alternative because they maintain the complex architecture of the endocrine and exocrine tissues, and do not suffer from the mechanical and chemical stress of enzymatic isolation. We report a fluidic pancreatic SliceChip platform with dynamic environmental controls that generates a warm, oxygenated, and bubble-free fluidic pathway across singular immobilized slices with continuous deliver of fresh media and the ability to perform repeat serial perfusion assessments. A degasser ensures the system remains bubble-free while systemic pressurization with compressed oxygen ensures slice medium remains adequately oxygenated. Computational modeling of perfusion and oxygen dynamics within SliceChip guide the system's physiomimetic culture conditions. Maintenance of the physiological glucose dependent insulin secretion profile across repeat perfusion assessments of individual pancreatic slices kept under physiological oxygen levels demonstrated the culture capacity of our platform. Fluorescent images acquired every 4 hours of transgenic murine pancreatic slices were reliably stable and recoverable over a 5 day period due to the inclusion of a 3D-printed bioinert metallic anchor that maintained slice position within the SliceChip. Our slice on a chip platform has the potential to expand the useability of human pancreatic slices for diabetes pathogenesis and the development of new therapeutic approaches, while also enabling organotypic culture and assessment of other tissue slices such as brain and patient tumors.

Self‐Assembled Multistable Scattering Mode for Versatile Energy‐Saving Smart Windows

AbstractSmart windows are crucial to dynamic control over light transmission to fulfill various demands in energy saving, privacy, and information display; however, most present technologies still perform a single function (often tint or haze adjustment) and require continuous electricity for operation. In this study, novel self‐assembled ionic liquid crystals (ILCs) doped with negative cholesteric liquid crystals (CLCs) to offer electrically switchable and stable scattering‐mode light modulators are presented. The novel smectic A phase based on the ILCs exhibits high solubility in the adopted nematics, enhancing the LC device's performance in several ways, including improved homogeneity, stable alignment quality, prolonged stability, and simplified fabrication. The LC device can potentially offer a dynamically rapid switching function between stable transparent (imperfect fingerprint textures) states and stable scattering (focal conic textures with small domains) states by using external stimuli and highly maintained multistable states for prolonged periods, even when the external stimuli are removed. The LC device also offers polarization‐independent scattering and transparent‐mode LC light modulators, low operating voltage, excellent contrast, and broad viewing angles. Its versatility and outstanding field‐off stability make it ideal for various applications such as smart lighting, building climate control, energy‐saving displays, and augmented reality (AR) glasses.

Investigating an Enhanced Approach for Greenhouse Climate Control: Optimising Cooling and Heating Systems

This study aimed to enhance greenhouse climate regulation by optimizing the efficiency of existing cooling and heating systems while considering external temperature and humidity conditions. We introduced an automated system capable of regulating the internal greenhouse environment, which underwent testing across 30 days in September 2021, with temperatures ranging from 26°C to 31°C and humidity from 65% to 70%. The system consistently monitored and adjusted the microclimate, with sensors capturing temperature and humidity data at 30-second intervals, amassing over 83,000 data entries for enhanced control accuracy. The automated regulation effectively maintained desired humidity, significantly reducing nighttime levels by 80% while carefully increasing daytime humidity to counteract external heat. Temperature control was largely successful, sustaining daytime levels around 32°C, but faced challenges in maintaining the target of 26°C during cooler nights. Energy consumption was optimized, with the automation leading to a significant 4-33% energy saving for cooling and an 8% saving in heating compared to traditional methods. Additionally, the system was accessible via a web interface, allowing for real-time climate tracking and prompt anomaly identification. In conclusion, the developed greenhouse automation system exhibited efficiency in equipment usage and improved temperature and humidity control. Further enhancements are required for lamp-based heating. This research contributes to the efficiency and reliability of greenhouse automation systems, mitigating risks associated with external environmental factors and enhancing stability, productivity, and disease and pest prevention.

Investigating an Enhanced Approach for Greenhouse Climate Control: Optimising Cooling and Heating Systems

This study aimed to enhance greenhouse climate regulation by optimizing the efficiency of existing cooling and heating systems while considering external temperature and humidity conditions. We introduced an automated system capable of regulating the internal greenhouse environment, which underwent testing across 30 days in September 2021, with temperatures ranging from 26°C to 31°C and humidity from 65% to 70%. The system consistently monitored and adjusted the microclimate, with sensors capturing temperature and humidity data at 30-second intervals, amassing over 83,000 data entries for enhanced control accuracy. The automated regulation effectively maintained desired humidity, significantly reducing nighttime levels by 80% while carefully increasing daytime humidity to counteract external heat. Temperature control was largely successful, sustaining daytime levels around 32°C, but faced challenges in maintaining the target of 26°C during cooler nights. Energy consumption was optimized, with the automation leading to a significant 4-33% energy saving for cooling and an 8% saving in heating compared to traditional methods. Additionally, the system was accessible via a web interface, allowing for real-time climate tracking and prompt anomaly identification. In conclusion, the developed greenhouse automation system exhibited efficiency in equipment usage and improved temperature and humidity control. Further enhancements are required for lamp-based heating. This research contributes to the efficiency and reliability of greenhouse automation systems, mitigating risks associated with external environmental factors and enhancing stability, productivity, and disease and pest prevention.

Natural and anthropogenic controls on environmental change during the Holocene based on a multi-proxy record obtained from subalpine peatland in southern China

The interactions between past climate, human activity and environmental change in subtropical mountainous areas are poorly understood due to the lack of reliable records in South China. In this study, the evolution of the East Asian summer monsoon (EASM) during the Holocene, and the interactions between regional human activity and environmental change, were studied using multi-proxy records from a subalpine peat core recovered from South China. The chronology of this peat core has been well-constrained by 10 AMS 14C dates of peat stems. A series of proxy indicators, including carbon isotopes (δ13C), loss on ignition (LOI), magnetic susceptibility (MS), the chemical index of alteration (CIA), and geochemical elements from the Shiwangutian (SWGT) peatland were used to reconstruct the palaeohydrological changes during the Holocene. Regional moisture levels showed a generally arid–wet–arid pattern, and three phases of climatic change were detected as follows. 1) Between 11,600 and 9000 cal yr BP, the EASM was weak and a relatively dry climate developed. 2) Between 9000 and 4000 cal yr BP, the prevalence of humid climatic conditions was associated with a strong summer monsoon. 3) After 4000 cal yr BP, the climate shifted to relatively dry conditions. Further comparisons and analysis suggested that solar insolation, migration of the Intertropical Convergence Zone (ITCZ), and El Niño-Southern Oscillation (ENSO) activity played an important role in determining the variations in Holocene EASM intensity. In addition, the increase in both MS and heavy metal concentrations over the last 1000 years is consistent with an increase in the population of Hunan Province. Therefore, it can be inferred that population growth and the associated expansion of cropland and mining led to an increase in soil erosion and metal tool use. These findings suggest that the impact of human activity generally outweighed the natural climatic controls on the environment and landscape in the mountainous region of southern China over the last 1000 years.

Transient thermal modelling of a Mediterranean greenhouse for sustainable agriculture: Comparison of desert and dry-summer subtropical climates

Climate change has become increasingly dominant in recent years and threatens food production and security in many areas worldwide. Due to the increase in temperature in some regions, there is a drought problem in agricultural food production, causing issues for food security. Intergovernmental Panel on Climate Change reported that climate change causes a reduction in crop quality and yield changes in farmer livelihoods. Greenhouse agriculture is a common and more protected farming management system than open-field farming. However, the influence of different climate regions on agricultural production in greenhouses should be investigated. In this study, thermal modeling of a greenhouse with and without ventilation is performed to determine the temperature and humidity variations of the greenhouse indoor air variations in selected provinces from Türkiye and Qatar to represent the effects of different climate regions. The impacts of variable climatic conditions on the greenhouse’s indoor and agricultural plants’ temperatures are investigated. Furthermore, implementing a heat pump as heating and cooling equipment in the greenhouse is studied. The yearly average vegetation and indoor temperature, respectively, are determined as 31.41 °C and 30.04 °C for Doha and 21.69 °C and 20.43 °C for Izmir. While the annual average unconditioned indoor temperature is found as 30.04 °C, the average conditioned indoor temperature is determined as 23.67 °C in Doha City. Moreover, the combined climate control mechanisms reduce the number of hours out of the optimum temperature range from 8013 to 1.4 and from 2640 to 3.1 in Doha and Izmir, respectively.

Biological and environmental controls on nighttime water-use behaviors in Populus simonii in semi-arid areas of the Chinese Loess plateau

Recent studies have revealed that the active nighttime water-use behaviors by trees have critical physio-ecological significance in survival and growth in adversity. However, the characteristics and biophysical control of nighttime water-use of silvicultural trees are not clear. We continuously monitored sap flow and leaf water potential (predawn and midday) of Populus simonii of different tree sizes as well as environmental factors during the 2021 and 2022 growing seasons (May-September) in a semi-arid area of Loess Plateau. Our results showed that both nighttime water-use (WUn) and the ratio of nighttime to daily water-use (WUn%) increased significantly with tree size, and had larger values in the drought year than in the normal year. The WUn% of different tree sizes ranged from 10.24 to 13.01% and can reach up to 36.49% during prolonged soil drought. Besides, the WUn% of different tree sizes were significantly positively and negatively correlated with nighttime vapor pressure deficit (VPDn) and soil water content, respectively. By partitioning the components of WUn, we found that as tree size increased, the stem water refilling (RE) and nighttime transpiration increased obviously, but the ratio of RE to WUn (RE%) did not change. The RE of different tree sizes constituted the major part of WUn with an average RE% of 65.7–68.0%, and the RE% was larger in the drought year than in the normal year. Additionally, the RE% of different tree sizes increased with decreasing predawn leaf water potential (Ѱpd) during the soil dry stage and with increasing VPDn during the soil wet stage. Given the increased risk of atmospheric drought and soil drought, it can be expected from our findings that the nighttime water-use behaviors of trees become more active in the future, which represents a significant performance of drought adaptation strategies of silvicultural species.

The Beginning of the Large-Scale Reconstruction of the Russian State Library: Architecture and Digitalization

The article reveals the foundations of design and research surveys, on the basis of which the Russian State Library (RSL) implemented the project of repair and restoration works for the central entrance of the library. The aim of the works was to adapt the cultural heritage object to modern use. The building complex, conceived in the mid — 1920s, was completed by 1940, but it was not fully commissioned until 1960. In the mid — 1970s, there was insufficient space to store the growing holdings. The front decoration of the central hall suffered enormous damage over the years. In 2019, a negative trend in the condition of the building was revealed. The main book depository was overloaded. The problems of the RSL are combined in a comprehensive investment programme for the reconstruction and restoration of infrastructure facilities. In 2019—2020, design solutions were developed for the repair and restoration of buildings and individual public spaces of the library. In 2021, the first stage of restoration of the entrance group began. The decision was made to carry out the work in a service-preserving environment and the challenge was to transform the very model of service to readers. The team working on the restoration made decisions reflecting the development of 21st century technologies and current standards for the automation of library processes. As a result of the works, new technological channels for the building operation and space for servicing readers were arranged, a climate control system was installed, the power supply and electric lighting system was replaced, historical interiors were restored, modern fire and engineering safety systems were created, a new centralized information and navigation complex for readers was deployed, etc. In 2023, a grandiose historical space was opened for the RSL readers.

Smart cement for fire alarms and indoor climate control

Fire alarms in buildings are essential for safety. However, due to the poor conductivity of cement, it remains a challenge to detect fire without the assistance of other monitoring equipment. In this study, a fire alarm cement composite containing expandable graphite, carbon fiber, and ordinary Portland cement that can achieve ultrasensitive temperature monitoring and indoor climate control in a building is developed. Homogeneously distributed expandable graphite in this smart cement rapidly expands under high temperatures, forming new electrically conductive pathways. This results in excellent temperature sensing performance, with a temperature coefficient of resistance of − 0.467 %/°C in the range of 220 °C–400 °C. The smart cement can be easily integrated into a building to transmit a fire alert to a computer, mobile phone, or visual alarm device in a timely manner. Furthermore, this smart cement exhibits higher flexural strength in harsh environments compared to ordinary cement. This smart cement exhibits potential to considerably broaden cement applications and be highly desirable for next-generation smart building materials.

Distinct, direct and climate‐mediated environmental controls on global particulate and mineral‐associated organic carbon storage

AbstractIdentifying controls on soil organic carbon (SOC) storage, and where SOC is most vulnerable to loss, are essential to managing soils for both climate change mitigation and global food security. However, we currently lack a comprehensive understanding of the global drivers of SOC storage, especially with regards to particulate (POC) and mineral‐associated organic carbon (MAOC). To better understand hierarchical controls on POC and MAOC, we applied path analyses to SOC fractions, climate (i.e., mean annual temperature [MAT] and mean annual precipitation minus potential evapotranspiration [MAP‐PET]), carbon (C) input (i.e., net primary production [NPP]), and soil property data synthesized from 72 published studies, along with data we generated from the National Ecological Observatory Network soil pits (n = 901 total observations). To assess the utility of investigating POC and MAOC separately in understanding SOC storage controls, we then compared these results with another path analysis predicting bulk SOC storage. We found that POC storage is negatively related to MAT and soil pH, while MAOC storage is positively related to NPP and MAP‐PET, but negatively related to soil % sand. Our path analysis predicting bulk SOC revealed similar trends but explained less variation in C storage than our POC and MAOC analyses. Given that temperature and pH impose constraints on microbial decomposition, this indicates that POC is primarily controlled by SOC loss processes. In contrast, strong relationships with variables related to plant productivity constraints, moisture, and mineral surface availability for sorption indicate that MAOC is primarily controlled by climate‐driven variations in C inputs to the soil, as well as C stabilization mechanisms. Altogether, these results demonstrate that global POC and MAOC storage are controlled by separate environmental variables, further justifying the need to quantify and model these C fractions separately to assess and forecast the responses of SOC storage to global change.

Climate and landscape control of runoff stable isotopes in the inland mountain

Study regionThe Xiying River Basin is a typical inland mountainous watershed located in the Qilian Mountains. Study focusThis article reveals the change of runoff stable isotopes and their control mechanisms based on isotope data of different water bodies (precipitation, runoff, groundwater, and glacial snowmelt) in the Xiying River Basin from 2016 to 2021, combined with relevant meteorological observation data and the Normalized Vegetation Index (NDVI). New hydrological insights for the regionThe results show that (1) meteorological factors control runoff isotope variations through controlling the evaporation process of runoff and the isotopic characteristics of recharge sources. (2) In areas with low vegetation cover, surface landscape features influence runoff isotopic composition by altering the isotopic characteristics of recharge sources. (3) In areas with high vegetation cover, surface vegetation cover affects runoff stable isotopes by controlling evapotranspiration processes. This study connects vegetation cover and runoff isotopes to explain the surface landscape control of runoff stable isotopes. It offers a more powerful reference for elucidating the factors influencing runoff isotopes in inland mountain watersheds.

Controls on Quaternary geochemical and mineralogical variability in the Koora Basin and South Kenya Rift

The South Kenya Rift is comprised of a series of N-S-oriented grabens with sediments that preserve an approximate one-million-year environmental history that reflects the interplay of climate, tectonism and volcanism. This study attempts to disentangle the relative roles of these major controls by comparing the geochemical records preserved in three sedimentary basins. The study focuses on the Koora Basin using bulk geochemical data in a 139-m-long core. This record is then compared with geochemical data and environmental histories from a 196-m-long core at Magadi and outcrops in the Olorgesailie Basin. Four climatic phases (1000–850; 850–470; 470–400; 400–0 ka) are recognised at Koora, which can also be distinguished in the Magadi and Olorgesailie Basins. However, inter-basin contrasts also suggest that additional, non-climatic factors influenced these geochemical histories, particularly during four intervals. These include 1) the Magadi Transition (MT; ∼770–700 ka), 2) the Magadi Tectonic Event (MTE; ∼540 ka), 3) the Koora Instability Period (KIP; ∼325–180 ka), and 4) the Trona Precipitation Period (TPP; ∼105–0 ka). Prior to the MT, Zr/TiO2, La/Lu, Mo, As, V and Na/Ca in Magadi and Koora cores were similar but afterwards diverged. Major reductions in transition metals at Magadi during the MTE reflect tectonically-induced cross-rift drainage diversion. This contrasts with the Koora and Olorgesailie basins where these metals were constant from ∼1000 to 300 ka. The KIP represents a significant increase in volcanic inputs to the Koora Basin and increased geochemical variability. Bromine (Br), which reflects peralkaline volcanic activity and/or evaporative concentration, is elevated during the KIP at Koora but is below detection limits in the rest of the Koora core. Br in the Magadi core does not correlate with that in the Koora record, suggesting contrasting accumulation processes. The TPP represents a phase of trona precipitation at Magadi but not at Koora. This difference partly reflects increased magmatic CO2 rising along faults in the Magadi basin during a period of increasing aridity. Rare-earth element patterns indicate a major change at Magadi with many anomalies after about 325 ka to the present, caused by the development of hypersaline waters, which did not occur at Koora or Olorgesailie. The geochemical data from the three basins help to partially separate climatic controls from those related to volcanism, tectonism and local geomorphology.

Environmental controls of winter soil carbon dioxide fluxes in boreal and tundra environments

Abstract. The carbon cycle in Arctic–boreal regions (ABRs) is an important component of the planetary carbon balance, with growing concerns about the consequences of ABR warming for the global climate system. The greatest uncertainty in annual carbon dioxide (CO2) budgets exists during winter, primarily due to challenges with data availability and limited spatial coverage in measurements. The goal of this study was to determine the main environmental controls of winter CO2 fluxes in ABRs over a latitudinal gradient (45∘ to 69∘ N) featuring four different ecosystem types: closed-crown coniferous boreal forest, open-crown coniferous boreal forest, erect-shrub tundra, and prostrate-shrub tundra. CO2 fluxes calculated using a snowpack diffusion gradient method (n=560) ranged from 0 to 1.05 g C m2 d−1. To assess the dominant environmental controls governing CO2 fluxes, a random forest machine learning approach was used. We identified soil temperature as the main control of winter CO2 fluxes with 68 % of relative model importance, except when soil liquid water occurred during 0 ∘C curtain conditions (i.e., Tsoil≈0 ∘C and liquid water coexist with ice in soil pores). Under zero-curtain conditions, liquid water content became the main control of CO2 fluxes with 87 % of relative model importance. We observed exponential regressions between CO2 fluxes and soil temperature in fully frozen soils (RMSE=0.024 gCm-2d-1; 70.3 % of mean FCO2) and soils around the freezing point (RMSE=0.286 gCm-2d-1; 112.4 % of mean FCO2). FCO2 increases more rapidly with Tsoil around the freezing point than at Tsoil<5 ∘C. In zero-curtain conditions, the strongest regression was found with soil liquid water content (RMSE=0.137 gCm-2d-1; 49.1 % of mean FCO2). This study shows the role of several variables in the spatio-temporal variability in CO2 fluxes in ABRs during winter and highlights that the complex vegetation–snow–soil interactions in northern environments must be considered when studying what drives the spatial variability in soil carbon emissions during winter.

The Environmental and Genetic Controls of Increment Suggest a Limited Adaptability of Native Populations of Norway Spruce to Weather Extremes

In the Baltics, warming is expected to burden the growth of Norway spruce Picea abies, with weather anomalies/extremes having strong triggering effects, which can be mitigated by tree breeding. Within the region, breeding programmes have been aiming for productivity, yet being conservative, their sustainability depends on the adaptability of native genotypes, which is unclear. The adaptability of genotypes can be assessed through local adaptations and phenotypic plasticity, with the sensitivity of increment depicting the conformity of genotypes and environments. To assess the adaptability of native populations to anticipated climates, local genetic adaptation and phenotypic plasticity of the weather sensitivity of the radial increment were assessed by the methods of time series analysis and quantitative genetics based on three clonal trials (low-density single-tree plot plantations of grafted clones of native plus trees) representing the local climatic gradient in Latvia. The growth of trees was sensitive to the moisture availability in summer and the thermal regime in winter, yet coinciding anomalies in both were associated with abrupt changes in tree ring width. These environmental effects differed among the clones, indicating genetic controls over the sensitivity of increment, which, however, decreased under a warmer climate, suggesting a limited adaptability of local populations to warming. Still, the weather-growth relationships showed moderate phenotypic plasticity, suggesting some mid-term adaptability. Accordingly, supplementation of breeding populations via assisted gene transfer with the genotypes that are adapted to warmer and drier climates appears crucial.

Aspect Matters: Unraveling Microclimate Impacts on Mountain Greenness and Greening

AbstractMountains are vital ecosystems, yet predicting plant growth there is complex due to diverse microclimates on slopes. Equatorial‐facing slopes (EFSs) are drier and warmer, and polar‐facing slopes (PFSs) are wetter and colder, than their regional macroclimates. Analyzing Moderate Resolution Imaging Spectroradiometer normalized difference vegetation index from 2003 to 2021, we identified a clear geographic pattern of differences in greenness on the two opposite aspects: EFSs were greener than PFSs in cold areas and were browner in dry areas, mainly determined by the relative importance of limitations of temperature and water. PFSs had stronger greening trends than did EPSs, leading to a weakening difference in greenness between EPSs and PFSs in temperature‐limited areas, and an intensifying difference in water‐limited areas. This suggests the alleviation of temperature limitation and exacerbation of water limitation. Montane ecosystems constitute a “natural laboratory” for deepening our understanding of the temporal evolution of the climatic control of vegetation growth with a space‐for‐time substitution.

Variations in Precipitation at the Shimantan Reservoir, China

Global warming substantially intensifies hydrologic cycles, causing increasing frequency and magnitude of catastrophic floods and droughts. Understanding the patterns and mechanisms of precipitation in historical periods is pivotal for regional disaster prevention and mitigation. Here, we analyzed the daily precipitation of six stations at the Shimantan Reservoir from 1952 to 2013 to examine precipitation characteristics at different time scales. The Mann–Kendall test, moving t-test, and Innovative Polygon Trend Analysis (IPTA) were employed to detect the trends and change points in total precipitation amount, frequency, and duration. Influences of atmospheric circulations on precipitation were then explored via cross-wavelet analysis. Our results showed increased average precipitation and decreased precipitation days annually at the Shimantan Reservoir in the past decades. Specifically, increased seasonal precipitation was only detected in summer, while precipitation days were mainly reduced in winter. There was a noticeable increasing to decreasing transition trend in precipitation from July to August, and a transition from decreasing to increasing from June to July in precipitation days. Summer rainfall was predominantly moderate and light, accompanied by shortening and highly fluctuating rainstorm durations. July exhibited the highest precipitation frequency and always experienced rainstorms. The Arctic Oscillation and East Asian summer monsoon showed positive and negative correlations, respectively, with the changes in precipitation at the Shimantan Reservoir. Our analyses provide a fine-scale portrait of precipitation patterns and mechanisms under a changing climate and benefit regional flood control and sustainable development.

Carbon capture from biomass flue gases for CO2 enrichment in greenhouses

Heating and CO2 enrichment systems can improve yields in intensive greenhouse agriculture Combining both techniques, which are currently applied commercially, can potentially enhance their effect. The CO2 must be separated from the other noxious gases present (such as CO, NOX, and SO2) to avoid them becoming part of the supply. The CO2 is then provided to the greenhouse on demand in the same way as the heating. In this work, we show that an improved food productivity of a pilot-scale greenhouse system combined with CO2 capture by adsorption using activated carbon and heating with alternative fuel. The proposed system's overall performance was evaluated and optimized. The best values were 46.7 g/kg of CO2 storage capacity on the adsorbent bed, 99.99 % removal rate harmful gases from the gas supplied to the greenhouse, CO2 levels of 1851.0 ± 262.8 mg/Nm3 of the CO2 levels in the greenhouse, and an enrichment time of 2.18 ± 0.92 h/day. The system's effective performance over extended periods (November–February) was confirmed and the productivity of a crop species (tomato) was compared to a control, showing an increment of 18 %. The results indicate that this is a valuable option for increasing the crop yield. By integrating this combined system with advanced climate control strategies, it is possible to maximize the CO2 provided per day, leading to higher yields. The system proved to be stable under real pilot-scale conditions over winter periods (four months).

Uncertainty modelling in the selection of climate control system manufacturers for preconstruction of hydroelectric power plants

Heating, ventilation, air conditioning, and refrigeration systems, the critical intersection point of low environmental impact, neutral thermal comfort and acceptable indoor air quality are technologies that directly affect the electricity generation of hydroelectric power plants on the axis of sustainability. Addressing challenges in decision-making for pre-construction system selection, this study employs fuzzy set theory, specifically Pythagorean and q-Rung Orthopair fuzzy sets, to model uncertainty in hydroelectric power plant specific considerations. Utilizing Analytic Hierarchy Process, Technique for Order of Preference by Similarity to Ideal Solution and the Complex Proportional Assessment the model evaluates ten global climate control system manufacturers. Sensitivity and comparative analysis ensure result validity, offering valuable insights for industry professionals and decision-makers, streamlining the complex process of selecting the most suitable manufacturer.

Responses of stomatal density and carbon isotope composition of sugar maple and yellow birch foliage to N, P and CaSiO3 fertilization.

Stomatal density, stomatal length and carbon isotope composition can all provide insights into environmental controls on photosynthesis and transpiration. Stomatal measurements can be time-consuming; it is therefore wise to consider efficient sampling schemes. Knowing the variance partitioning at different measurement levels (i.e., among stands, plots, trees, leaves and within leaves) can aid in making informed decisions around where to focus sampling effort. In this study, we explored the effects of nitrogen (N), phosphorus (P) and calcium silicate (CaSiO3) addition on stomatal density, length and carbon isotope composition (δ13C) of sugar maple (Acer saccharum Marsh.) and yellow birch (Betula alleghaniensis Britton). We observed a positive but small (8%) increase in stomatal density with P addition and an increase in δ13C with N and CaSiO3 addition in sugar maple, but we did not observe effects of nutrient addition on these characteristics in yellow birch. Variability was highest within leaves and among trees for stomatal density and highest among stomata for stomatal length. To reduce variability and increase chances of detecting treatment differences in stomatal density and length, future protocols should consider pretreatment and repeated measurements of trees over time or measure more trees per plot, increase the number of leaf impressions or standardize their locations, measure more stomata per image and ensure consistent light availability.