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Dry ice has been proposed as a propellant for electric propulsion, as its use may facilitate the realization of a low-cost propulsion system compared to that based on a xenon propellant. In addition, dry ice can be obtained from space (e.g., from the atmosphere of Mars) and human exhalation. This study thus conducted experiments with dry ice storage and carbon dioxide gas supply using triple-point storage. With this method, a constant tank pressure and flow rate was achieved without the application of regulators or control valves. However, the triple-point state was unexpectedly halted, even though solid dry ice remained in the tank. An internal visual observation revealed that the solid phase was surrounded by the liquid phase, which prevented the solid phase from melting. Therefore, heat conduction fins were installed in the tank to enhance the melting process, which successfully extended the triple-point duration. The supply system was applied successfully to the operation of a 1 kW Hall thruster. Furthermore, a mathematical model for estimating the phase characteristics in the tank was developed, with an in-orbit operation analyzed based on the experimental results. The heat input to the tank and the mass flow rate or enthalpy to the thruster determined the phase characteristics in the tank, which means that implementing a thermal design that considers the flow rate to the thruster is crucial. The simulation demonstrated that dry ice can be consumed by controlling the three phases in the tank using an electrical heater. A gas phase separator concept consisting of the heat conduction fins and capillary screen mesh was proposed for orbital microgravity operation.

Sequestration of CO2 within stable mineral carbonates (e.g., CaCO3) represents an attractive emission reduction strategy as it offers a leakage-free alternative to geological storage of CO2 in an environmentally benign form. However, the pH of aqueous streams equilibrated with gaseous streams containing CO2 (pH < 4) are typically lower than that which is required for carbonate precipitation (pH > 8). Traditionally, alkalinity is provided by a stoichiometric reagent (e.g., NaOH) which renders these processes environmentally hazardous and economically unfeasible. This work investigates the use of regenerable ion-exchange materials to induce alkalinity in CO2-saturated aqueous solutions such that the pH shift required for mineralization occurs without the need for stoichiometric reagents. Na+-H+ exchange isotherms (at [H+] = 10-8-10-1 M) and rates were measured for 13X and 4A zeolites and TP-207 and TP-260 organic exchange resins in batch equilibrium and fixed-bed exchange experiments, respectively. At solutions equilibrated with CO2 at 1.0 atm (pH = 3.9), H+ exchange capacities for the materials were similar (1.7-2.4 mmol H+/g material) and resulted in pH increases from 3.9 to greater than 8.0. Multi-component mixtures using Ca2+ and Mg2+ cations (at 10-3-10-1 M) in CO2-saturated water were used to probe competitive ion exchange. The presence of divalent cations in solution inhibited H+ exchange, reducing capacities to as low as 0.2 mmol H+/g for both resins and zeolites. Dynamic H+ exchange capacities in fixed-bed ion exchange columns were similar-to equilibrium values for resins (~1.5 mmol/g) and zeolites (~0.8 mmol/g) using inlet solutions that were equilibrated with gaseous streams of CO2 at 1.0 atm. For the four ion exchange materials studied (e.g., ion exchange resins and synthetic zeolites), quasi-chemical linear driving-force approximations that are in first order in solid-phase capacity, effectively model contaminant breakthrough curves. Experimentally

Identification of the breathing cycle forms the basis of any breath-by-breath gas exchange analysis. Classically, the breathing cycle is defined as the time interval between the beginning of two consecutive inspiration phases. Based on this definition, several research groups have developed algorithms designed to estimate the volume and rate of gas transferred across the alveolar membrane ("alveolar gas exchange"); however, most algorithms require measurement of lung volume at the beginning of the ith breath (VLi-1; i.e., the end-expiratory lung volume of the preceding ith breath). The main limitation of these algorithms is that direct measurement of VLi-1 is challenging and often unavailable. Two solutions avoid the requirement to measure VLi-1 by redefining the breathing cycle. One method defines the breathing cycle as the time between two equal fractional concentrations of lung expired oxygen (Fo2) (or carbon dioxide; Fco2), typically in the alveolar phase, whereas the other uses the time between equal values of the Fo2/Fn2 (or Fco2/Fn2) ratios [i.e., the ratio of fractional concentrations of lung expired O2 (or CO2) and nitrogen (N2)]. Thus, these methods identify the breathing cycle by analyzing the gas fraction traces rather than the gas flow signal. In this review, we define the traditional approach and two alternative definitions of the human breathing cycle and present the rationale for redefining this term. We also explore the strengths and limitations of the available approaches and provide implications for future studies.

Permafrost thaw causes the seasonally thawed active layer to deepen, causing the Arctic to shift toward carbon release as soil organic matter becomes susceptible to decomposition. Ground subsidence initiated by ice loss can cause these soils to collapse abruptly, rapidly shifting soil moisture as microtopography changes and also accelerating carbon and nutrient mobilization. The uncertainty of soil moisture trajectories during thaw makes it difficult to predict the role of abrupt thaw in suppressing or exacerbating carbon losses. In this study, we investigated the role of shifting soil moisture conditions on carbon dioxide fluxes during a 13-year permafrost warming experiment that exhibited abrupt thaw. Warming deepened the active layer differentially across treatments, leading to variable rates of subsidence and formation of thermokarst depressions. In turn, differential subsidence caused a gradient of moisture conditions, with some plots becoming consistently inundated with water within thermokarst depressions and others exhibiting generally dry, but more variable soil moisture conditions outside of thermokarst depressions. Experimentally induced permafrost thaw initially drove increasing rates of growing season gross primary productivity (GPP), ecosystem respiration (Reco ), and net ecosystem exchange (NEE) (higher carbon uptake), but the formation of thermokarst depressions began to reverse this trend with a high level of spatial heterogeneity. Plots that subsided at the slowest rate stayed relatively dry and supported higher CO2 fluxes throughout the 13-year experiment, while plots that subsided very rapidly into the center of a thermokarst feature became consistently wet and experienced a rapid decline in growing season GPP, Reco , and NEE (lower carbon uptake or carbon release). These findings indicate that Earth system models, which do not simulate subsidence and often predict drier active layer conditions, likely overestimate net growing season carbon uptak

Given the superior stability, technologically developed and cost effectiveness of carbon-based perovskite solar cells over conventional metallic electrode-based architectures, this work investigates the environmental performance of two industrial front-runners architectures i.e., high temperature processed carbon-based perovskite solar modules (CPSMs) and low temperature processed CPSMs using cradle-to-gate Life Cycle Assessment analysis assuming a manufacturing plant in India. According to the study, most of the impacts are due to energy consumption in the annealing and screen print paste process used in ETL, perovskite, HTL and cathode layer for both the architectures. Material selection for the perovskite and other layers has a significant environmental impact on both architectures. Compared to low temperature processed architecture, high temperature processed CPSMs have a greater environmental impact. For a five-year lifetime, the global warming potential (GWP) values for high temperature and low temperature processed CPSMs are 0.180 kg CO2-eq and 0.126 kg CO2-eq, respectively, which are marginally higher than those indicated for commercially available silicon solar cells. Thus, a sensitivity analysis was performed to determine the minimum lifetime required to compete with GWP values comparable to commercial PVs. High and low temperature processed CPSM needed 16 and 11 years of lifetime, respectively, to match silicon's 25 years of lifetime. On the other hand, the study finds the human toxicity contribution by mono-silicon is extremely high compared to the two CPSM architectures because of the contribution by electricity (44.01%) and use of heavy metals such as copper (16.83%) and steel (11.52%). © 2023 The Authors

The presence of oil and gas production fields, oil refineries, cement plants, and coal-fired power plants situated close to each other supports the program for zero CO_2 emissions through Carbon Capture, Utilization, and Storage (CCUS) for Enhanced Oil Recovery (EOR). This study aims to investigate the potential of depleted fields in the North West Java Basin as the target for CCUS-EOR in fulfilling the zero CO_2 emission program and boosting oil production. The study uses oil and gas field data to evaluate the CCUS potential both qualitatively and quantitatively. The Geographic Information System was applied through a clustering method with a 50 km and 100 km buffer from CO_2 emission sources. The calculation of CO_2 for EOR purposes with a 50 km buffer radius is 287.504 million tons, which could result in a 575.009 million stock tank barrel (STB) increase in oil production in the case of immiscible injection and 379.506 million tons for an increase of about 1.150 billion STB of oil production in the case of miscible injection. For a 100 km buffer radius, 632.541 million tons of CO_2 is required to increase 1.265 billion STB of oil production in the case of immiscible injection and 834.955 million tons of CO_2 for an increase of 2.530 billion STB of oil production in the case of miscible injection. These results are expected to be implemented as part of the program to reach the goal of producing 1 million barrels of oil per day by 2030 and achieving net zero emissions by 2060.

Estimates of ocean CO2 uptake from global ocean biogeochemistry models and pCO(2)-based data products differ substantially, especially in high latitudes and in the trend of the CO2 uptake since 2000. Here, we assess the effect of data sparsity on two pCO(2)-based estimates by subsampling output from a global ocean biogeochemistry model. The estimates of the ocean CO2 uptake are improved from a sampling scheme that mimics present-day sampling to an ideal sampling scheme with 1000 evenly distributed sites. In particular, insufficient sampling has given rise to strong biases in the trend of the ocean carbon sink in the pCO(2) products. The overestimation of the CO2 flux trend by 20-35% globally and 50-130% in the Southern Ocean with the present-day sampling is reduced to less than 15% with the ideal sampling scheme. A substantial overestimation of the decadal variability of the Southern Ocean carbon sink occurs in one product and appears related to a skewed data distribution in pCO(2) space. With the ideal sampling, the bias in the mean CO2 flux is reduced from 9-12% to 2-9% globally and from 14-26% to 5-17% in the Southern Ocean. On top of that, discrepancies of about 0.4 PgC yr(-1) (15%) persist due to uncertainties in the gas-exchange calculation.This article is part of a discussion meeting issue 'Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities'.

The Southern Ocean is among the largest contemporary sinks of atmospheric carbon dioxide on our planet; however, remoteness, harsh weather and other circumstances have led to an undersampling of the ocean basin, compared with its northern hemispheric counterparts. While novel data interpolation methods can in part compensate for such data sparsity, recent studies raised awareness that we have hit a wall of unavoidable uncertainties in air-sea CO2 flux reconstructions. Here, we present results from autonomous observing campaigns using a novel platform to observe remote ocean regions: sailboats. Sailboats are at present a free of charge environmentally friendly platform that recurrently pass remote ocean regions during round-the-globe racing events. During the past 5 years, we collected >350 000 measurements of the sea surface partial pressure of CO2 (pCO(2)) around the globe including the Southern Ocean throughout an Antarctic circumnavigation during the Vendee Globe racing event. Our analysis demonstrates that the sailboat tracks pass regions where large uncertainty in the air-sea CO2 flux reconstruction prevails, with regional oversaturation or undersaturation of the sea surface pCO(2). Sailboat races provide an independent cross-calibration platform for autonomous measurement devices, such as Argo floats, ultimately strengthening the entire Southern Ocean observing system.This article is part of a discussion meeting issue 'Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities'.

As a part of global warming reduction strategies, CO2 capture and storage (CCS) is considered a promising and effective method, which can be classified as absorption and adsorption, chemical looping combustion and cryogenic distillation, hydrate-based separation, and membrane separation. But, the high energy requirement, solvent loss and degradation, corrosive nature, and toxicity of solvents can limit the applications. Developing novel techniques and materials are attracting high attention to achieve superior capacities. The supported ionic liquid membranes (SILMs) as a part of ionic liquids (ILs) have shown great potential for efficient and cost-effective separation of CO2 from the gaseous flow. The present review demonstrates the mechanisms, advantages, difficulties, and disadvantages of CO2 capture by SILMs and compares them with various conventional methods. A major part of this review covers the tunability of SILMs, experimental data of solubility, diffusivity, permeability, and selectivity of CO2 in various combinations of ILs, membrane supports, and additives. Lastly, the stability of SILMs, reusability of ILs, membrane wetting, challenges, and future recommendations are presented., Peer Reviewed, Postprint (published version)

Mineral particles capture water vapor in the atmosphere in the form of water films that are only few monolayers thick. Water films form nanoscale hydration environments that mediate a wide range of important reactions in nature and technology. This thesis explored two important phenomena that commonly occur within the confines of water films: mineralogical transformations (Topic 1) and photocatalytic decomposition of organics (Topic 2). These transformations were chiefly identified by vibrational spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and (Transmission and Scanning) electron microscopy. Interpretations of reaction mechanisms were partially supported by chemometrics, kinetic and thermodynamic modeling, as well as molecular simulations. Mineralogical transformations (Topic 1) resolved in this thesis involved the hydroxylation (Papers I, II) and carbonation (Paper III) of periclase (MgO), and the oxidation of rhodochrosite (MnCO3) (Paper IV). Two types of MgO nanocubes with contrasting physical properties were used to resolve nucleation- and diffusion-limited hydroxylation reactions to brucite and carbonation reactions to amorphous magnesium carbonate (AMC). While nucleation-limited reactions completely transformed (8 nm) small and aggregated MgO nanocubes to brucite, the reactions became diffusion-limited in larger (32 nm) monodispersed MgO nanocubes because of brucite surface nanocoatings (Paper I). Additionally, brucite nanosheets grew under (GPa-level) crystallization pressures because of the important volumetric expansion of the reaction, which took place in a complex network of microporosity between the small and within the larger MgO nanocubes. Brucite stacking mechanisms, explored in Paper II, focused on the early stages of MgO-water interaction in water films of different thicknesses. These were suggested to involve the stacking and (epitaxial-like) growth of precursor Mg(OH)2 nanosheets in water films. Carbonation reactions explored

This PhD dissertation work delves into critical issues within the forestry business related to carbon sequestration, land value maximization and climate change vulnerability. The study proposes different tools to enhance the efficiency and outcomes of forest practices. Chapter two involves an enhanced forest rotation deferral methodology for carbon dioxide sequestration, focusing on the forest's final product destination passed the Faustmann optimal rotation age. Instead of giving the same value for pulp wood and saw timber, the research acknowledges the benefit of increased carbon dioxide stored in saw timber materials. To drive landowners to the socially optimum rotation age, where the marginal benefits of extended carbon storage equal the private marginal cost of postponing forest rotation, an incentive based mechanism is proposed, using subsidies. Through sensitivity analysis on the underlying assumptions, the socially optimal rotation is consistently greater than the currently applied one-year harvesting deferral, and smaller than longer extensions, such as 20 years deferred rotations. In chapter three, a novel approach to design Streamside Management Zones widths that vary according to different landscape characteristics is presented, as opposed to the constant command and control width currently used in Virginia. This adaptive approach allows landowners to maximize land value, while ensuring water quality protection. To determine the sediment retention equation as a function of SMZ slope, width, and soil texture, we use data derived from the Watershed Erosion Prediction Project. By simulating different regulatory constraints concerning accepted sediment delivery, the study shows the tradeoff between water quality and land expectation value through the changes in the opportunity cost of Streamside Management Zones. Lastly, chapter four centers on a dataset collected in India about tree planting species choice followed by a second model that incorporates socio

Cover crops can increase carbon (C) sequestration in soils. However, there is limited understanding of how cover crops affect carbon dioxide (CO2) and nitrous oxide (N2O) fluxes from agricultural soils in the Canadian Prairies. Research was conducted at the Trace Gas Manitoba (TGAS-MAN) long-term research site to determine the effect of a fall rye (Secale cereale L.) cover crop on spring-thaw and post-fertilizer N2O emissions, CO2 fluxes, and grain yield. Fluxes were measured over four years (2019-2022) from four 4-ha fields using the flux gradient method. In the fall of 2018 two fields were seeded no-till with fall rye and two were cultivated and left into winter. The cover crop was terminated the following spring with an herbicide application and the cash crops oats (Avena sativa), canola (Brassica napus), and spring wheat (Triticum aestivum L.) were grown in 2019, 2020, 2021, and 2022. 2020 and 2021 CO2 fluxes were removed due to unreliable data caused by flux measurement equipment. In 2019, C assimilation by the cover crop resulted in the system being a C sink of 424 kg C ha-1 after accounting for harvest removals, and the conventional system was a C source of 248 kg C ha-1. In 2022, wet growing conditions resulted in both cropping systems being a C source, with the conventional and cover crop system losing 1,366 kg C ha-1 and 1,558 kg C ha-1, respectively. The cover crop fields saw lower spring-thaw N2O emissions during years of good cover crop establishment. N2O emissions following fertilizer application and cumulative N2O fluxes were lower in cover crop fields in all study years. Combining cumulative CO2 fluxes and N2O emissions in CO2-equivalents (CO2-eq) in 2019 and 2022, the cover crop system was a net greenhouse gas source of 5,665 CO2-eq ha-1 and the conventional system was a source of 7,653 CO2-eq ha-1. The cover crop did not significantly affect crop yields.

The enormous challenge of climate change is discussed and debated today because of its major impact on life on Earth. The forests have an important role to play as the plants absorb carbon dioxide (CO2) from the atmosphere through their photosynthesis and the growing tree retain carbon (C). Hence, the larger the growth the greater the carbon storage and climate benefit. The demand for wood and wood products is increasing as well as the ongoing debate about forest management. Therefore, alternative management methods to increase wood production is of interest and the effects these methods could have on climate change mitigation. In this context this Thesis deals with the effect of fertilization on carbon balance and growth in young forest as well as flows of the greenhouse gases, CO2, methane (CH4), and nitrous oxide (N2O) from forest land. In addition, it deals also with the reliability and comparability of different measurement methods which are compared with respect to the carbon balance. The studies have been carried out in a young mixed stand of Norway spruce (Picea abies (L.) Karst) and birch (Betula pendula and B.pubescens) on a storm-felled (Gudrun 2005) area in southern Sweden, Kronoberg county. Part of the area was fertilized with 150 kg N ha-1 everysecond year from 2014 and forward, while the other part was kept unfertilized. In the unfertilized part a dose experiment was set up where 0,150, 300, and 450 kg N ha-1 were added to investigate the impact of the different fertilizer levels on forest floor greenhouse gas fluxes. Chamber measurements of forest floor fluxes, eddy-flux measurements of stand net-fluxes and tree measurements of height, diameter and birch leaf biomass were conducted in different, occasionally overlapping, periods in the years 2013-2021. The results show that even if the flows of CO2 from the forest floor increase initially after a first standard fertilization, the effect decreases quickly. The net fluxes show that the stands become ca, Den stora utmaningen med de pågående klimatförändringarna har sedan Kyotoprotokollet 1997 diskuterats med en ökande intensitet eftersom dessa har en avgörande inverkan på livet på jorden. Skogen har en viktig roll att spela då växterna genom sin fotosyntes tar upp koldioxid (CO2) från atmosfären och det växande trädet binder in kol (C). Ju högre tillväxten är, desto större är kolinlagringen och klimatnyttan. Efterfrågan på trä och träprodukter liksom den pågående debatten om skogsskötsel intensifierats. Därför är alternativa skogsskötselmetoder för att öka virkesproduktionen intressanta att studera liksom deras påverkan på klimatförändringarna. Med detta som bakgrund behandlar denna avhandling effekten av gödsling avseende skogens kolbalans, närmare bestämt tillväxt i ungskog samt flöden av växthusgaserna, CO2, metan (CH4) och lustgas (N2O) från skogsmark. Dessutom behandlar den tillförlitligheten i och jämförbarheten av olika mätmetoder med avseende på skogens kolbalans. Studierna har genomförts i ett ungt blandbestånd av gran (Picea abies(L.) Karst) och björk (Betula pendula and Betula pubescens) på ett ca 60 hektar stort område, utanför Ljungby i Kronobergs län, som blåste ned istormen Gudrun år 2005. Under åren 2013 till 2021 genomfördes redovisade kammarmätningar av markflöden av växthusgaser, eddyfluxmätningar av växthusgasers nettoflöden på beståndsnivå, skogsuppskattning av trädslag, höjd och diameter samt insamling av björkblad. Mätningarna var delvis överlappande i tid. En del av området gödslades ett långtidsförsök med 150 kg kväve (N) per hektar vartannat år från 2014. Den andra delen behölls ogödslad. På en del av den ogödslade delen inrättades 2016 ett giveförsök där 0, 150, 300 och 450 kg N per hektar tillfördes för att undersöka de olika nivåernas påverkan på växthusgasflödena från marken. Resultaten visar att även om flödet av koldioxid från marken intitialt ökar efter en första standardgödsling så avtar effekten snabbt. När kolinbindningen i växter

The enormous challenge of climate change is discussed and debated today because of its major impact on life on Earth. The forests have an important role to play as the plants absorb carbon dioxide (CO2) from the atmosphere through their photosynthesis and the growing tree retain carbon (C). Hence, the larger the growth the greater the carbon storage and climate benefit. The demand for wood and wood products is increasing as well as the ongoing debate about forest management. Therefore, alternative management methods to increase wood production is of interest and the effects these methods could have on climate change mitigation. In this context this Thesis deals with the effect of fertilization on carbon balance and growth in young forest as well as flows of the greenhouse gases, CO2, methane (CH4), and nitrous oxide (N2O) from forest land. In addition, it deals also with the reliability and comparability of different measurement methods which are compared with respect to the carbon balance. The studies have been carried out in a young mixed stand of Norway spruce (Picea abies (L.) Karst) and birch (Betula pendula and B.pubescens) on a storm-felled (Gudrun 2005) area in southern Sweden, Kronoberg county. Part of the area was fertilized with 150 kg N ha-1 everysecond year from 2014 and forward, while the other part was kept unfertilized. In the unfertilized part a dose experiment was set up where 0,150, 300, and 450 kg N ha-1 were added to investigate the impact of the different fertilizer levels on forest floor greenhouse gas fluxes. Chamber measurements of forest floor fluxes, eddy-flux measurements of stand net-fluxes and tree measurements of height, diameter and birch leaf biomass were conducted in different, occasionally overlapping, periods in the years 2013-2021. The results show that even if the flows of CO2 from the forest floor increase initially after a first standard fertilization, the effect decreases quickly. The net fluxes show that the stands become ca, Den stora utmaningen med de pågående klimatförändringarna har sedan Kyotoprotokollet 1997 diskuterats med en ökande intensitet eftersom dessa har en avgörande inverkan på livet på jorden. Skogen har en viktig roll att spela då växterna genom sin fotosyntes tar upp koldioxid (CO2) från atmosfären och det växande trädet binder in kol (C). Ju högre tillväxten är, desto större är kolinlagringen och klimatnyttan. Efterfrågan på trä och träprodukter liksom den pågående debatten om skogsskötsel intensifierats. Därför är alternativa skogsskötselmetoder för att öka virkesproduktionen intressanta att studera liksom deras påverkan på klimatförändringarna. Med detta som bakgrund behandlar denna avhandling effekten av gödsling avseende skogens kolbalans, närmare bestämt tillväxt i ungskog samt flöden av växthusgaserna, CO2, metan (CH4) och lustgas (N2O) från skogsmark. Dessutom behandlar den tillförlitligheten i och jämförbarheten av olika mätmetoder med avseende på skogens kolbalans. Studierna har genomförts i ett ungt blandbestånd av gran (Picea abies(L.) Karst) och björk (Betula pendula and Betula pubescens) på ett ca 60 hektar stort område, utanför Ljungby i Kronobergs län, som blåste ned istormen Gudrun år 2005. Under åren 2013 till 2021 genomfördes redovisade kammarmätningar av markflöden av växthusgaser, eddyfluxmätningar av växthusgasers nettoflöden på beståndsnivå, skogsuppskattning av trädslag, höjd och diameter samt insamling av björkblad. Mätningarna var delvis överlappande i tid. En del av området gödslades ett långtidsförsök med 150 kg kväve (N) per hektar vartannat år från 2014. Den andra delen behölls ogödslad. På en del av den ogödslade delen inrättades 2016 ett giveförsök där 0, 150, 300 och 450 kg N per hektar tillfördes för att undersöka de olika nivåernas påverkan på växthusgasflödena från marken. Resultaten visar att även om flödet av koldioxid från marken intitialt ökar efter en första standardgödsling så avtar effekten snabbt. När kolinbindningen i växter

Integrating CO2 capture with biomass/waste fired combined heat and power (CHP) plants is a promising method to achieve negative emissions. However, the use of versatile biomass/waste and the dynamic operation of CHP plants result in bigger fluctuations in the properties of flue gas (FG), e.g. CO2 concentration (CO2vol%) and flowrates, and the heat that can be used for CO2 capture, when comparing with coal fired power plants. To address such a challenge, dynamic modelling is essential to accurately estimate the amount of captured CO2 and optimize the operation of CO2 capture. This paper compares three dynamic approaches commonly used in literature, namely using the ideal static model (IST) and using dynamic models without control (Dw/oC) and with control (DwC), for MEA based chemical absorption CO2 capture. The performance of approaches is assessed under the variations of key factors, including the flowrate and CO2vol% of FG, and the available heat for CO2 capture. Simulation results show clear differences. For example, when the CO2vol% drops from 15.7 % to 9.7 % (about 38 %) within 4 hours, DwC gives the highest amount of captured CO2, which is 7.3 % and 22.3 % higher than IST and Dw/oC, respectively. It is also found that the time step size has a clear impact on the CO2 capture amount, especially for DwC. Based on the results, suggestions are also provided regarding the selection of dynamic modelling approaches for different purposes of simulations.

The enormous challenge of climate change is discussed and debated today because of its major impact on life on Earth. The forests have an important role to play as the plants absorb carbon dioxide (CO2) from the atmosphere through their photosynthesis and the growing tree retain carbon (C). Hence, the larger the growth the greater the carbon storage and climate benefit. The demand for wood and wood products is increasing as well as the ongoing debate about forest management. Therefore, alternative management methods to increase wood production is of interest and the effects these methods could have on climate change mitigation. In this context this Thesis deals with the effect of fertilization on carbon balance and growth in young forest as well as flows of the greenhouse gases, CO2, methane (CH4), and nitrous oxide (N2O) from forest land. In addition, it deals also with the reliability and comparability of different measurement methods which are compared with respect to the carbon balance. The studies have been carried out in a young mixed stand of Norway spruce (Picea abies (L.) Karst) and birch (Betula pendula and B.pubescens) on a storm-felled (Gudrun 2005) area in southern Sweden, Kronoberg county. Part of the area was fertilized with 150 kg N ha-1 everysecond year from 2014 and forward, while the other part was kept unfertilized. In the unfertilized part a dose experiment was set up where 0,150, 300, and 450 kg N ha-1 were added to investigate the impact of the different fertilizer levels on forest floor greenhouse gas fluxes. Chamber measurements of forest floor fluxes, eddy-flux measurements of stand net-fluxes and tree measurements of height, diameter and birch leaf biomass were conducted in different, occasionally overlapping, periods in the years 2013-2021. The results show that even if the flows of CO2 from the forest floor increase initially after a first standard fertilization, the effect decreases quickly. The net fluxes show that the stands become ca, Den stora utmaningen med de pågående klimatförändringarna har sedan Kyotoprotokollet 1997 diskuterats med en ökande intensitet eftersom dessa har en avgörande inverkan på livet på jorden. Skogen har en viktig roll att spela då växterna genom sin fotosyntes tar upp koldioxid (CO2) från atmosfären och det växande trädet binder in kol (C). Ju högre tillväxten är, desto större är kolinlagringen och klimatnyttan. Efterfrågan på trä och träprodukter liksom den pågående debatten om skogsskötsel intensifierats. Därför är alternativa skogsskötselmetoder för att öka virkesproduktionen intressanta att studera liksom deras påverkan på klimatförändringarna. Med detta som bakgrund behandlar denna avhandling effekten av gödsling avseende skogens kolbalans, närmare bestämt tillväxt i ungskog samt flöden av växthusgaserna, CO2, metan (CH4) och lustgas (N2O) från skogsmark. Dessutom behandlar den tillförlitligheten i och jämförbarheten av olika mätmetoder med avseende på skogens kolbalans. Studierna har genomförts i ett ungt blandbestånd av gran (Picea abies(L.) Karst) och björk (Betula pendula and Betula pubescens) på ett ca 60 hektar stort område, utanför Ljungby i Kronobergs län, som blåste ned istormen Gudrun år 2005. Under åren 2013 till 2021 genomfördes redovisade kammarmätningar av markflöden av växthusgaser, eddyfluxmätningar av växthusgasers nettoflöden på beståndsnivå, skogsuppskattning av trädslag, höjd och diameter samt insamling av björkblad. Mätningarna var delvis överlappande i tid. En del av området gödslades ett långtidsförsök med 150 kg kväve (N) per hektar vartannat år från 2014. Den andra delen behölls ogödslad. På en del av den ogödslade delen inrättades 2016 ett giveförsök där 0, 150, 300 och 450 kg N per hektar tillfördes för att undersöka de olika nivåernas påverkan på växthusgasflödena från marken. Resultaten visar att även om flödet av koldioxid från marken intitialt ökar efter en första standardgödsling så avtar effekten snabbt. När kolinbindningen i växter

The activation and functionalization of carbon dioxide entails great interest related to its abundance, low toxicity and associated environmental problems. However, the inertness of CO2 has posed a challenge towards its efficient conversion to added-value products. In this review we discuss one of the strategies that have been widely used to capture and activate carbon dioxide, namely the use of donor-acceptor interactions by partnering a Lewis acidic and a Lewis basic fragment. This type of CO2 activation resembles that found in metalloenzymes, whose outstanding performance in catalytically transforming carbon dioxide encourages further bioinspired research. We have divided this review into three general sections based on the nature of the active sites: metal-free examples (mainly formed by frustrated Lewis pairs), main group-transition metal combinations, and transition metal heterobimetallic complexes. Overall, we discuss one hundred compounds that cooperatively activate carbon dioxide by donor-acceptor interactions, revealing a wide range of structural motifs.

The reaction of seventeen borane derivatives of five-membered N-heterocyclic rings (BNHRs) with CO has been studied by means of DFT calculations. Several non-covalent complexes between the BNHRs and CO which evolve through a TS in a single adduct for each BNHR have been identified. The calculated IRC of the TS has allowed to identify the non-covalent complex involved in the reaction in each case. The stationary points of the reactions have been analyzed with the distortion/interaction partition model. In addition, empirical models have been attempted to correlate the acid (fluoride ion affinity) and basic (proton affinity) properties of the isolated BNHR with the TS barriers and adduct energies. The energetics of the reactions are influenced by the number of nitrogen atoms in the ring.

The challenges of combatting climate change are unprecedented and now very urgent. Current approaches are not working fast enough. This paper, and this journal issue, conceive of the challenge as one of non-marginal structural and institutional change. Several different conceptual frameworks and pluralist theories are considered, emanating from complexity theory, economics, natural sciences, political economy, and strategy. These are deployed to identify potential accelerators, including synergies between climate action and other key political issues, and beneficial non-linear dynamics such as shifts in consumer preferences and technology learning curves. The delays in action also mean that removing carbon dioxide from the atmosphere is now necessary, and even unconventional geoengineering approaches may need to be considered. A pluralist and practical approach to climate action, accounting for different institutional and social contexts across countries, is argued to be required to accelerate action. © The Author(s) 2023.

Disease conditions that involve multiple predisposing or contributing factors, or manifest as low performance and/or low-level mortality, can pose a diagnostic challenge that requires an interdisciplinary approach. Reaching a diagnosis may also be limited by a lack of available clinical profile parameter reference ranges to discriminate healthy fish from those affected by specific disease conditions. Here, we describe our experience investigating poorly performing rainbow trout (Oncorhynchus mykiss) in an intensive recirculation aquaculture, where reaching a final diagnosis of nephrocalcinosis was not as straightforward as one would wish. To list the issues making the diagnosis difficult, it was necessary to consider the creeping onset of the problem. Further diagnostic steps needed to ensure success included obtaining comparative data for fish blood profiles and water quality from both test and control aquacultural systems, excluding infections with salmonid pathogenic agents and evaluating necropsy findings. Major events in the pathophysiology of nephrocalcinosis could be reconstructed as follows: aquatic environment hyperoxia and hypercapnia RIGHTWARDS ARROW blood hypercapnia RIGHTWARDS ARROW blood acid-base perturbation (respiratory acidosis) RIGHTWARDS ARROW metabolic compensation (blood bicarbonate elevation and kidney phosphate excretion) RIGHTWARDS ARROW a rise in blood pH RIGHTWARDS ARROW calcium phosphate precipitation and deposition in tissues. This case highlights the need to consider the interplay between water quality and fish health when diagnosing fish diseases and reaching causal diagnoses.

Disease conditions that involve multiple predisposing or contributing factors, or manifest as low performance and/or low-level mortality, can pose a diagnostic challenge that requires an interdisciplinary approach. Reaching a diagnosis may also be limited by a lack of available clinical profile parameter reference ranges to discriminate healthy fish from those affected by specific disease conditions. Here, we describe our experience investigating poorly performing rainbow trout (Oncorhynchus mykiss) in an intensive recirculation aquaculture, where reaching a final diagnosis of nephrocalcinosis was not as straightforward as one would wish. To list the issues making the diagnosis difficult, it was necessary to consider the creeping onset of the problem. Further diagnostic steps needed to ensure success included obtaining comparative data for fish blood profiles and water quality from both test and control aquacultural systems, excluding infections with salmonid pathogenic agents and evaluating necropsy findings. Major events in the pathophysiology of nephrocalcinosis could be reconstructed as follows: aquatic environment hyperoxia and hypercapnia RIGHTWARDS ARROW blood hypercapnia RIGHTWARDS ARROW blood acid-base perturbation (respiratory acidosis) RIGHTWARDS ARROW metabolic compensation (blood bicarbonate elevation and kidney phosphate excretion) RIGHTWARDS ARROW a rise in blood pH RIGHTWARDS ARROW calcium phosphate precipitation and deposition in tissues. This case highlights the need to consider the interplay between water quality and fish health when diagnosing fish diseases and reaching causal diagnoses., info:eu-repo/semantics/openAccess

Disease conditions that involve multiple predisposing or contributing factors, or manifest as low performance and/or low-level mortality, can pose a diagnostic challenge that requires an interdisciplinary approach. Reaching a diagnosis may also be limited by a lack of available clinical profile parameter reference ranges to discriminate healthy fish from those affected by specific disease conditions. Here, we describe our experience investigating poorly performing rainbow trout (Oncorhynchus mykiss) in an intensive recirculation aquaculture, where reaching a final diagnosis of nephrocalcinosis was not as straightforward as one would wish. To list the issues making the diagnosis difficult, it was necessary to consider the creeping onset of the problem. Further diagnostic steps needed to ensure success included obtaining comparative data for fish blood profiles and water quality from both test and control aquacultural systems, excluding infections with salmonid pathogenic agents and evaluating necropsy findings. Major events in the pathophysiology of nephrocalcinosis could be reconstructed as follows: aquatic environment hyperoxia and hypercapnia RIGHTWARDS ARROW blood hypercapnia RIGHTWARDS ARROW blood acid-base perturbation (respiratory acidosis) RIGHTWARDS ARROW metabolic compensation (blood bicarbonate elevation and kidney phosphate excretion) RIGHTWARDS ARROW a rise in blood pH RIGHTWARDS ARROW calcium phosphate precipitation and deposition in tissues. This case highlights the need to consider the interplay between water quality and fish health when diagnosing fish diseases and reaching causal diagnoses., info:eu-repo/semantics/openAccess

The enormous challenge of climate change is discussed and debated today because of its major impact on life on Earth. The forests have an important role to play as the plants absorb carbon dioxide (CO2) from the atmosphere through their photosynthesis and the growing tree retain carbon (C). Hence, the larger the growth the greater the carbon storage and climate benefit. The demand for wood and wood products is increasing as well as the ongoing debate about forest management. Therefore, alternative management methods to increase wood production is of interest and the effects these methods could have on climate change mitigation. In this context this Thesis deals with the effect of fertilization on carbon balance and growth in young forest as well as flows of the greenhouse gases, CO2, methane (CH4), and nitrous oxide (N2O) from forest land. In addition, it deals also with the reliability and comparability of different measurement methods which are compared with respect to the carbon balance. The studies have been carried out in a young mixed stand of Norway spruce (Picea abies (L.) Karst) and birch (Betula pendula and B.pubescens) on a storm-felled (Gudrun 2005) area in southern Sweden, Kronoberg county. Part of the area was fertilized with 150 kg N ha-1 everysecond year from 2014 and forward, while the other part was kept unfertilized. In the unfertilized part a dose experiment was set up where 0,150, 300, and 450 kg N ha-1 were added to investigate the impact of the different fertilizer levels on forest floor greenhouse gas fluxes. Chamber measurements of forest floor fluxes, eddy-flux measurements of stand net-fluxes and tree measurements of height, diameter and birch leaf biomass were conducted in different, occasionally overlapping, periods in the years 2013-2021. The results show that even if the flows of CO2 from the forest floor increase initially after a first standard fertilization, the effect decreases quickly. The net fluxes show that the stands become ca, Den stora utmaningen med de pågående klimatförändringarna har sedan Kyotoprotokollet 1997 diskuterats med en ökande intensitet eftersom dessa har en avgörande inverkan på livet på jorden. Skogen har en viktig roll att spela då växterna genom sin fotosyntes tar upp koldioxid (CO2) från atmosfären och det växande trädet binder in kol (C). Ju högre tillväxten är, desto större är kolinlagringen och klimatnyttan. Efterfrågan på trä och träprodukter liksom den pågående debatten om skogsskötsel intensifierats. Därför är alternativa skogsskötselmetoder för att öka virkesproduktionen intressanta att studera liksom deras påverkan på klimatförändringarna. Med detta som bakgrund behandlar denna avhandling effekten av gödsling avseende skogens kolbalans, närmare bestämt tillväxt i ungskog samt flöden av växthusgaserna, CO2, metan (CH4) och lustgas (N2O) från skogsmark. Dessutom behandlar den tillförlitligheten i och jämförbarheten av olika mätmetoder med avseende på skogens kolbalans. Studierna har genomförts i ett ungt blandbestånd av gran (Picea abies(L.) Karst) och björk (Betula pendula and Betula pubescens) på ett ca 60 hektar stort område, utanför Ljungby i Kronobergs län, som blåste ned istormen Gudrun år 2005. Under åren 2013 till 2021 genomfördes redovisade kammarmätningar av markflöden av växthusgaser, eddyfluxmätningar av växthusgasers nettoflöden på beståndsnivå, skogsuppskattning av trädslag, höjd och diameter samt insamling av björkblad. Mätningarna var delvis överlappande i tid. En del av området gödslades ett långtidsförsök med 150 kg kväve (N) per hektar vartannat år från 2014. Den andra delen behölls ogödslad. På en del av den ogödslade delen inrättades 2016 ett giveförsök där 0, 150, 300 och 450 kg N per hektar tillfördes för att undersöka de olika nivåernas påverkan på växthusgasflödena från marken. Resultaten visar att även om flödet av koldioxid från marken intitialt ökar efter en första standardgödsling så avtar effekten snabbt. När kolinbindningen i växter

1:1 Co-crystals of carbamazepine (CBZ) and saccharin (SAC) were obtained for the first time through the supercritical anti-solvent (SAS) technique based on using supercritical CO2 as anti-solvent. The capability of SAS to produce the desired polymorphic form (two polymorphs are known) was assessed. Operational conditions investigated were temperature (40.0 and 60.0 °C), pressure (10.0 and 15.0 MPa), solvent choice and coformer concentration in the organic solution (CBZ: 30 and 15 mg/mL; SAC: stoichiometric ratio). Co-crystals were characterized in terms of crystallinity and coformers interactions. No homocrystals were present. Using methanol, at 40.0 °C polymorph I was obtained with yields up to 65%; whilst at 60.0 °C a mixture of polymorphs was obtained. Mixtures of polymorphs were also obtained in the ethanol and dichloromethane experiments at the studied conditions while the dimethylsulfoxide experiments failed to produce any co-crystal polymorph. For comparison purposes, pure CBZ and SAC were also processed by SAS., Depto. de Química Física, Fac. de Ciencias Químicas, TRUE, pub

Negatieve emissies of koolstofverwijdering — processen waarbij broeikasgassen uit de atmosfeer permanent of langdurig worden verwijderd — worden steeds vaker gezien als een onderdeel in de gereedschapskist voor klimaatbeleid. Zo zijn in alle scenario’s van het IPCC negatieve emissies nodig om klimaatneutraliteit in 2050 te bereiken. Dit onderzoek, in opdracht van het ministerie van Economische Zaken en Klimaat, brengt de technische en beleidsmatige aspecten van dit onderwerp in kaart. Het geeft een actueel beeld van de toekomstige behoefte, aanbod en mogelijke tijdpaden voor negatieve emissies, gaat in op de rol van CCS, en geeft inzicht in de behoefte aan en de opties voor beleid.

Op een landbouwbedrijf is er altijd veel leven in de brouwerij, of boerderij. Toch zijn er jaarlijks heel wat ongevallen, vaak met dodelijke afloop… en dat heeft lang niet altijd met het gebruik van zware machines te maken, er zijn ook veel ‘stille’ gevaren, zoals mestgassen.

Het klimaat verandert. Om te kunnen anticiperen op de veranderingen, is het van groot belang dat de uitstoot aan broeikasgassen sterk wordt gereduceerd. Waterschap De Dommel streeft dan ook naar een klimaat neutrale bedrijfsvoering in 2035. Energie-efficiency en opwekking van duurzame energie is daar onlosmakelijk aan verbonden. Met de voorliggende voortgangsrapportage wordt jaarlijks inzicht gegeven in de huidige CO2-uitstoot van de organisatie, de energiehuishouding en de behaalde resultaten. Deze voortgangsrapportage wordt mede opgesteld in het kader van de CO2- prestatielade. Dit is de eerste rapportage na de certificering van de organisatie in 2022.

Drained agriculturally used peatlands are hotspots for greenhouse gas (GHG) emissions, especially carbon dioxide (CO2) and nitrous oxide (N2O). To reduce GHG emissions and simultaneously maintain intensive grassland use, raising water levels by subsurface irrigation (SI) is controversially discussed. Both, intensive grassland use and installations of SI may require grassland renewal. We investigated an experimental intervention site (INT) (SI target water levels: -0.30 m) and a deeply drained reference site (REF), both intensive grassland on deep bog peat. After installation of the SI system, a mechanical grassland renewal took place at INT. At both sites, CO2 (eddy covariance), N2O and methane (manual closed chamber technique) were measured. Additionally, soil water was analyzed for nitrogen species. Here, we report on the initial year of GHG measurements including grassland renewal and rising water levels. Overall, GHG emissions were strongly influenced by grassland renewal at INT. Despite progressively rising water levels, soil moisture in the upper centimeters was low and thus grass growth was slow, resulting in an almost complete loss of harvest. This resulted in a net ecosystem carbon balance (NECB) of 4.64 ± 1.03 t C ha−1 containing only 0.57 ± 0.09 t C ha−1 harvest at INT, while NECB at REF was 6.08 ± 1.74 t C ha−1 including harvest from five grass cuts. Methane fluxes were negligible at both sites. Nitrous oxide emissions dominated the GHG balance at INT. With 144.5 ± 45.5 kg N2O–N ha–1 a–1, they were much higher than at REF (3.9 ± 3.1 kg N2O–N ha–1 a–1) and any other values published so far. Peak fluxes occurred when nitrate concentrations in soil water were extremely high, soil moisture was increased, and vegetation development was struggling. This study highlights the risk of grassland renewals on peat soils regarding yield losses as well as high GHG emissions.

Snow is critically important to the energy budget, biogeochemistry, ecology, and people of the Arctic. While climate change continues to shorten the duration of the snow cover period, snow mass (the depth of the snow pack) has been increasing in many parts of the Arctic. Previous work has shown that deeper snow can rapidly thaw permafrost and expose the large amounts of ancient (legacy) organic matter contained within it to microbial decomposition. This process releases carbonaceous greenhouse gases but also nutrients, which promote plant growth and carbon sequestration. The net effect of increased snow depth on greenhouse gas emissions from Arctic ecosystems remains uncertain. Here we show that 25 years of snow addition turned tussock tundra, one of the most spatially extensive Arctic ecosystems, into a year-round source of ancient carbon dioxide. More snow quadrupled the amount of organic matter available to microbial decomposition, much of it previously preserved in permafrost, due to deeper seasonal thaw, soil compaction and subsidence as well as the proliferation of deciduous shrubs that lead to 10% greater carbon uptake during the growing season. However, more snow also sustained warmer soil temperatures, causing greater carbon loss during winter (+200% from October to May) and year-round. We find that increasing snow mass will accelerate the ongoing transformation of Arctic ecosystems and cause earlier-than-expected losses of climate-warming legacy carbon from permafrost.

Diese Forschungsarbeit analysiert die Auswirkung der beiden existierenden regionalen Cap-and-Trade-Systeme für CO2 in den USA, das kalifornische Cap-and-Trade-System und die Regional Greenhouse Gas Initiative (RGGI), auf regionale Beschäftigung und die Anzahl von Firmensitzen. Mit Hilfe des County Business Patterns (CBP) Datensatzes auf County-Industrie-Niveau, schätze ich Difference-in-Difference Modelle für die Cap-and-Trade-Regionen zwischen 2004 und 2016. Dies ergänze ich durch Daten des CARB Mandatory GHG Reporting und berechne so Triple-Difference-Schätzungen. Damit prüfe ich für Kalifornien, ob die Maßnahme unterschiedliche Auswirkungen auf direkt regulierte Branchen hatte. Nach Einführung des Cap-and-Trade-Mechanismus ist ein durchschnittlicher Anstieg der Beschäftigung der kalifornischen Branchen auf County-Niveau um 3,1 % ceteris paribus messbar. Für die RGGI-Zone ist keine statistisch signifikante Auswirkung auf die Beschäftigung messbar. Ebenso ist in keiner der beiden Cap-and-Trade-Zonen eine unterschiedliche Auswirkung auf die direkt regulierten Branchen zu beobachten. Diese Ergebnisse sind robust gegenüber verschiedenen Imputationsmethoden und Definitionen betroffener Branchen. Was die Anzahl der Firmensitze anbelangt, so unterstützen die gesammelten Daten nicht die Annahme paralleler Trends zwischen den Vergleichsgruppen. Diese Annahme wäre für eine sinnvolle Interpretation der Differenzkoeffizienten erforderlich. Es gibt jedoch Anhaltspunkte dafür, dass sich der gemessene Beschäftigungseffekt in Regionen mit einem hohen Anteil direkt regulierter Wirtschaftstätigkeiten entfaltet, statt in allen direkt regulierten Branchen. Diese Ergebnisse könnten eher mit beschäftigungsfördernder Steuerumverteilung und Innovationsanreizen als mit Faktorsubstitution zusammenhängen., This paper analyses the impact of the two existing regional Cap-and-Trade systems for CO2 in the USA, the Californian Cap-and-Trade system and the Regional Greenhouse Gas Initiative (RGGI), on regional employment and establishment count. Using 2004-2016 county-industry level data from the County Business Patterns (CBP), I estimate difference-in-differences models for each Cap-and-Trade zone and supplement industry-coverage data for California from the CARB Mandatory GHG Reporting to compute triple-difference models and test whether policy effects differ for directly regulated industries. Following this approach, I find an average 3.1% increase in employment for Californian county-industries after the introduction of the policy holding all else equal. For the RGGI, no significant impact on employment is found. In neither of the two Cap-and-Trade zones a differential effect on directly regulated industries is observed. These results are robust to different imputation methods and measures of industry coverage. Concerning the establishment count, the gathered data does not support the assumption of parallel trends across groups, which is necessary to interpret difference-in-differences coefficients meaningfully. Some evidence is found that the measured employment effect unfolds in regions with a high share of directly regulated economic activity, rather than across directly regulated industries. These findings may be linked to labour-inducing tax redistribution and incentivised innovation, rather than factor substitution.

Vegetation dynamics optimally adapt to given environmental conditions by maximising their net carbon profit. If we model these processes, can they help us understand hydrological fluxes across different climates? Furthermore, can this optimality modelling further our understanding on the sensitivity of carbon-water mechanisms in vegetation to changes in CO2? This thesis uses a vegetation optimality model across multiple biomes in Brazil to examine the extent to which it can answer these questions. Firstly, we examine the reliability and suitability of five high-resolution meteorological gridded products (ERA5-Land, GLDAS2.0, GLDAS2.1, the BNMD and MSWEPv2.2 (precipitation only)) for seven variables (precipitation, air temperature, wind speed, pressure, specific humidity, and downward shortwave and longwave radiation) against eleven flux towers spanning five biomes across Brazil. At the daily scale analysis showed that MSWEPv2.2 outperformed the others for precipitation whilst ERA5-Land showed the most consistency for all other variables. Secondly, we show that the Vegetation Optimality Model (VOM), is successfully able to reproduce patterns of evapotranspiration (ET) at several sites, with a stronger correlation at more seasonal sites (r values ranging 0.25 – 0.69 across sites). VOM is a developed model that attempts to quantify the physiological processes of a plant growth carbon-capture cost-benefit system through describing carbon-water dynamics. Results show the importance of root dynamics in the success of the model; the minimal calibration needed per site reflects the strong physiological understanding behind it. Finally, we show declines in ET across an increasing atmospheric CO2 gradient, with dampened impacts on hydrological processes through modelling long-term adaptations in vegetation (reductions from 0.7-6.0% over an increase of 77 ppm CO2). Overall, this thesis advances our knowledge in relation to the questions above i

More environment-friendly solvents in analytical chemistry are almost inevitable in both sample preparation and analysis to meet the high standards of sustainable chemistry and human welfare. In this review paper, a critical look at the advantages and still unsolved problems of most potential classes of green solvents is presented to give an overview of the current state-of-the-art in this field. Replacing volatile organic compounds (VOCs) by ecofriendly and benign solvents in extractions/separations in sample preparation, as the most tedious and demanding step in analysis, is one of roads toward sustainable chemistry. Water under sub- and supercritical conditions, carbon-dioxide, ionic liquids (ILs), deep eutectic solvents (DESs), and those of natural origin (NADES) belong to the most promising classes of solvents in green analytical chemistry. Basic theory and mechanisms of their use illustrated by representative but not exhaustive list of examples related to complex matrices (environmental and natural food products) from analytical practice are presented in this review. Perspectives of QuEChERS, in line with GAC principles, are highlighted, in line with current trends of “going green” for quick, easy, cheap, effective, rugged, and safe analytical methods. Compliance with green chemistry (GC), especially green analytical chemistry (GAC) principles, is not a fashionable issue but, more the trend toward a sustainable future with greener chemistry; thus, green metrics are an unavoidable tool to measure how green the applied method or procedure is. Herein, the most common tools will be presented and discussed, such as national environmental method index (NEMI), analytical ecoscale, green analytical procedure index (GAPI), analytical greenness calculator (AGREE), complementary green analytical procedure index (ComplexGAPI), and analytical greenness metric for sample preparation (AGREEprep). The future trends for research and development in this still expanding field ar

The continuous flow reverse water gas shift (rWGS) process was efficiently catalyzed by a plasmonic Au/TiO2 nanocatalyst using sunlight as sole and sustainable energy source. The influence of the catalyst bed thickness on the CO production rate was studied, and three different catalytic regimes were identified as direct plasmon catalysis (DPC), shielded plasmon catalysis (SPC) and unused plasmon catalysis (UPC). The CO2 : H2 ratio was optimized to 4 : 1 and a maximum CO production rate of 7420 mmol ⋅ m−2 ⋅ h−1 was achieved under mild reaction conditions (p=3.5 bar, no external heating, Ee=14.0 kW ⋅ m−2), corresponding to an aparent quantum efficiency of 4.15%. The stability of the Au/TiO2 catalyst was studied for 110 h continuous operation, maintaining more than 82% of the initial CO production rate. On/off experiments mimicking discontinuous sunlight powered processing furthermore showed that the Au/TiO2 catalyst was stable for 8 consecutive runs.

Producción Científica, Three different mesoporous iron based nanoparticles (NPs) were added to Chlorella sorokiniana batch cultures devoted to photosynthetic biogas upgrading to enhance CO2 biofixation: Fe2O3, carbon coated zero valent iron NPs containing 7.26 % (wt%) of iron (CALPECH NPs) and carbon coated zero valent iron NPs containing 31.38 % (wt%) of iron (SMALLOPS NPS). The three types of NPs enhanced CO2 adsorption and therefore biogas upgrading in tests conducted in 1.2 L enclosed photobioreactors. However, the addition of 70 mg L−1 of CALPECH NPs resulted in a 2-fold enhancement in the microalgae productivity, and a carbohydrate and lipid content increase by 56 % and 25 %, respectively compared to the control assay. Under UV and visible light irradiation the addition of Fe2O3 NPs resulted in a 5.3-times fold enhancement in carbohydrate content when 70 mg L−1 was added. Similarly, the addition of 20 mg L−1 of SMALLOPS NPs increased the lipid content by 11 % under UV irradiation. Interestingly, CALPECH NPs did not significantly influence C. sorokiniana composition, suggesting that these particular NPs can act as UV scavengers. Therefore, the addition of mesoporous nanoparticles could improve CO2 fixation and microalgae productivity during photosynthetic biogas upgrading., Junta de Castilla y Leon - Fondo Europeo de Desarrollo Regional (grants CLU 2017-09, CL-EI-2021-07 and UIC 315), Universidad Nacional Autónoma de México (project IN108922)

The rapid development in technology and changing food habits have drastically altered the cooking method in recent years. Electric ovens are dominating the cooking sector in bakeries, restaurants, and domestic cooking. India holds the second position in terms of revenue generated by the sales of cookers and ovens. The electrical energy requirements are also adding up with electricity-based cooking. In addition, solar energy-dependent solar cooking appliances are available in the market, but they come with their own set of merits and demerits. This paper discusses the new concept and development of an Electric-Solar hybrid cooking appliance. The implemented control mechanism in the fully-featured hybrid OTG (Oven, Toaster, & Griller) oven shows the simplicity and ease of using solar energy in conjunction with electrical energy. The experimental and numerical results show that the temperature distribution inside an electric-solar hybrid oven saves energy up to 51% and takes much less cooking time than electric ovens and solar cooking appliances when operating in hybrid mode. The STEPCO (Solar Thermal-Electric Powered Cooking Oven) oven has demonstrated potential for a relatively quick return on investment, with a payback period of around 2.3 years in hybrid mode and 3.7 years in solar mode. Experimental testing has shown that the hybrid mode of the STEPCO oven achieves an impressive efficiency of 63%, which is significantly higher than that of the electric and solar modes, which are only 35% and 4.0%, respectively. Additionally, the STEPCO oven has the environmental benefit of emitting very little CO2 during the cooking process when used in hybrid mode and zero CO2 emissions when used in solar mode. © 2023

Terrestrial ecosystems have taken up about 32% of the total anthropogenic CO2 emissions in the past six decades1. Large uncertainties in terrestrial carbon-climate feedbacks, however, make it difficult to predict how the land carbon sink will respond to future climate change2. Interannual variations in the atmospheric CO2 growth rate (CGR) are dominated by land-atmosphere carbon fluxes in the tropics, providing an opportunity to explore land carbon-climate interactions3-6. It is thought that variations in CGR are largely controlled by temperature7-10 but there is also evidence for a tight coupling between water availability and CGR11. Here, we use a record of global atmospheric CO2, terrestrial water storage and precipitation data to investigate changes in the interannual relationship between tropical land climate conditions and CGR under a changing climate. We find that the interannual relationship between tropical water availability and CGR became increasingly negative during 1989-2018 compared to 1960-1989. This could be related to spatiotemporal changes in tropical water availability anomalies driven by shifts in El Niño/Southern Oscillation teleconnections, including declining spatial compensatory water effects9. We also demonstrate that most state-of-the-art coupled Earth System and Land Surface models do not reproduce the intensifying water-carbon coupling. Our results indicate that tropical water availability is increasingly controlling the interannual variability of the terrestrial carbon cycle and modulating tropical terrestrial carbon-climate feedbacks.

Many chemosensory cues evoke responses of the same valence under widely varying physiological conditions. It remains unclear whether similar or distinct neural mechanisms are involved in the detection and processing of such chemosensory cues across contexts. We show that in Caenorhabditis elegans, a chemosensory cue is processed by distinct neural mechanisms at two different life stages that share the same valence state. Both starved adults and dauer larvae are attracted to carbon dioxide (CO2), but CO2 evokes different patterns of neural activity and different motor outputs at the two life stages. Moreover, the same interneuron within the CO2 microcircuit plays a different role in driving CO2-evoked motor output at the two life stages. The dauer-specific patterns of CO2-evoked activity in this interneuron require a dauer-specific gap junction complex and insulin signaling. Our results demonstrate that functionally distinct microcircuits are engaged in response to a chemosensory cue that triggers the same valence state at different life stages, revealing an unexpected complexity to chemosensory processing.

Då man producerar cement släpps koldioxid ut från både förbränningen av bränslet och kalcineringen av kalksten för att bilda bränd kalk. En del av koldioxiden, motsvarande den som släpps ut vid kalcineringen, kommer kunna absorberas av den härdade betongen. Denna process kallas karbonatisering och rör sig som en front från betongens yta och inåt. Ett sätt som ibland används för att bygga miljövänligare är att återanvända krossad betong från demolerade betongstrukturer till ballast till nyblandad betong. En betongvägg som även innehåller ballast av betong skulle därmed absorbera mer koldioxid än en betongvägg utan betongballast. Företaget Mapei AB har utvecklat ett pulver som kan suga åt sig överskottsbetongbetong då den roterar i en betongblandarbil och forma den till kulor med varierande storlek. Dessa kulor kan användas som ballast inom ny betongproduktion medan de absorberar koldioxid. I denna litteraturstudie undersöktes hur mycket koldioxid 1 m3 återvunnen betong kunde karbonatisera då den förvarades för sig själv samt hur mycket den återvunna betongballasten kunde karbonatiseras då den används i en 1 m3 betongvägg. Även förutsättningarna för karbonatisering undersöktes för att kunna lägga fram optimala förhållanden att absorbera koldioxiden. Om den återvunna betongballasten kunde ersätta ballast av jungfruligt material till 100 % kunde den mesta av koldioxiden från kalcineringen vid cementproduktionen absorberas för en betongvägg. Undersökningen visade även att ballasten kunde karbonatiseras avsevärt innan den tillsattes i betongblandingen om den förvarades med tillgång till luft och även utsattes för väta., When producing cement, carbon dioxide is released from both the combustion of the fuel and the calcination of limestone to form quicklime. Part of this carbon dioxide, corresponding to that released during calcination, can be absorbed by the hardened concrete by a process called carbonation that moves like a front from the surface of the concrete inwards. One way that is sometimes used to build more environmentally friendly is to reuse crushed concrete from demolished concrete structures as aggregate for freshly mixed concrete. A concrete wall that also contains such recycled concrete aggregate would thus absorb more carbon dioxide than a concrete wall without concrete aggregate. The company Mapei AB has developed a powder that can absorb excess concrete as it rotates in a concrete mixer truck and form it into balls of varying sizes. These balls can be used as aggregate in new concrete production while absorbing carbon dioxide. In this literature study, it was investigated how much carbon dioxide 1 m3 of recycled concrete could carbonize when it was stored by itself and how much the recycled concrete aggregate could carbonize when it was used in a 1 m3 concrete wall. The conditions for carbonation were also investigated in order to present optimal conditions for absorbing the carbon dioxide. If the recycled concrete aggregate could replace 100% virgin material aggregate, most of the carbon dioxide from the calcination in cement production could be absorbed for a concrete wall. The investigation also showed that the aggregate could be significantly carbonated before it was added to the concrete mix if it was stored with access to air and also exposed to moisture

With climate change resulting from a history of uncontrolled greenhouse gas emissions, all parts of society now need to take action - maybe most importantly the private sector. Since 2015 the Science Based Targets (SBT) initiative has committed over 5000 companies worldwide to heavily reduce their total emissions at a pace that scientists deem necessary for average global temperature rise to stay below 2℃. However despite a growing engagement from small to medium sized enterprises (SMEs), no research has yet investigated the experiences these small businesses have had with SBT - which this work aims to change with aid of the following research questions: What possibilities and challenges do small and medium sized enterprises experience in their work with Science Based Targets?, and, Are there any major problems with Science Based Targets that risk jeopardizing the initiatives aim in small and medium sized enterprises? By conducting semi-structured qualitative interviews with 13 Swedish SMEs and 3 experts, this report summarizes and analyzes the key areas that benefit or challenge SBTs. In summary, this study shows that the strength in SBT comes from its size and indirect ability to help companies work together with a specific common goal. A common challenge is an internal lack of specific knowledge typically regarding emission calculations and methods. Here SBT has been ambiguous and difficult to reach, resulting in a reliance on consultants as intermediaries. In order to effectivize this initiative, SBT needs to cater specifically to SMEs and further define their requirements - especially regarding scope 3 goals, relative measurements and corporate growth. I also recommend adjusting the simplifications made for SMEs as they do not reflect, but rather limit their high engagement. Hopefully this study opens up for further research on SMEs' role and work in the green transition., Lärdomar från småföretag som minskar sina utsläpp med Science Based Targets Vi vet alla hur viktigt det är att stoppa klimatförändringarna som sker, men ansvaret kanske inte alltid ligger på dig eller mig. Ofta fokuseras det på vad vi kan göra som individer, men alla problem hade inte löst sig även om vi slutade flyga eller åt mer vegetariskt. Omställningen måste även göras av företagen som står för utsläppen. Ett initiativ för att påskynda detta är Science Based Targets (SBT), där anslutna företag lovar att minska sina växthusgasutsläpp till netto noll före år 2050. Trots stor potential finns det dock ännu inte mycket forskning kring initiativ som SBT, och ännu mindre vetskap om hur de är att jobba med för de anslutna företagen. I denna studie har svenska småföretag anslutna till SBT intervjuats för att synliggöra deras erfarenheter, både bra och dåliga. Det visar sig finnas mycket kvar att lära av hur småföretag arbetar för att driva positiv förändring. Kortfattat är styrkan med Science Based Targets initiativet dess storlek och status med över 5000 anslutna företag, men även som en anledning för samarbete mellan dem. Initiativet ger ett gemensamt mål som kunder och leverantörer kan arbeta mot tillsammans. Detta samarbete skapar även information och kunskap som leder till fördelar i resten av företagens verksamheter. Det kan dock ibland vara svårt för småföretag att driva SBT då de intervjuade som mest hade runt 100 anställda och det sällan finns någon anställd med spetskompetens inom miljöarbete. Företagen upplever också att SBT ofta är väldigt otydliga med vad som måste göras i praktiken, och i kombination med brist på anpassad hjälp är det många som förlitat sig på konsulter. För att förbättras kan initiativet förtydliga sina förväntningar för småföretag, samt erbjuda mer konkret hjälp anpassad för deras storlek. Tilltron för initiativet är dock högre än någonsin eftersom allt fler företag ansluter sig från alla branscher och storlekar. Utöver initiativet vill

Large greenhouse gas emissions occur via the release of carbon dioxide (CO2) and methane (CH4) from the surface layer of lakes. Such emissions are modeled from the air-water gas concentration gradient and the gas transfer velocity (k). The links between k and the physical properties of the gas and water have led to the development of methods to convert k between gases through Schmidt number normalization. However, recent observations have found that such normalization of apparent k estimates from field measurements can yield different results for CH4 and CO2. We estimated k for CO2 and CH4 from measurements of concentration gradients and fluxes in four contrasting lakes and found consistently higher (on an average 1.7 times) normalized apparent k values for CO2 than CH4. From these results, we infer that several gas-specific factors, including chemical and biological processes within the water surface microlayer, can influence apparent k estimates. We highlight the importance of accurately measuring relevant air-water gas concentration gradients and considering gas-specific processes when estimating k.

The Southern Ocean is among the largest contemporary sinks of atmospheric carbon dioxide on our planet; however, remoteness, harsh weather and other circumstances have led to an undersampling of the ocean basin, compared with its northern hemispheric counterparts. While novel data interpolation methods can in part compensate for such data sparsity, recent studies raised awareness that we have hit a wall of unavoidable uncertainties in air-sea [Formula: see text] flux reconstructions. Here, we present results from autonomous observing campaigns using a novel platform to observe remote ocean regions: sailboats. Sailboats are at present a free of charge environmentally friendly platform that recurrently pass remote ocean regions during round-the-globe racing events. During the past 5 years, we collected [Formula: see text] measurements of the sea surface partial pressure of [Formula: see text] (p[Formula: see text]) around the globe including the Southern Ocean throughout an Antarctic circumnavigation during the Vendée Globe racing event. Our analysis demonstrates that the sailboat tracks pass regions where large uncertainty in the air-sea [Formula: see text] flux reconstruction prevails, with regional oversaturation or undersaturation of the sea surface p[Formula: see text]. Sailboat races provide an independent cross-calibration platform for autonomous measurement devices, such as Argo floats, ultimately strengthening the entire Southern Ocean observing system. This article is part of a discussion meeting issue 'Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities'.

Diatoms, dinoflagellates, and coccolithophores are dominant groups of marine eukaryotic phytoplankton that are collectively responsible for the majority of primary production in the ocean.1 These phytoplankton contain additional intracellular membranes around their chloroplasts, which are derived from ancestral engulfment of red microalgae by unicellular heterotrophic eukaryotes that led to secondary and tertiary endosymbiosis.2 However, the selectable evolutionary advantage of these membranes and the physiological significance for extant phytoplankton remain poorly understood. Since intracellular digestive vacuoles are ubiquitously acidified by V-type H+-ATPase (VHA),3 proton pumps were proposed to acidify the microenvironment around secondary chloroplasts to promote the dehydration of dissolved inorganic carbon (DIC) into CO2, thus enhancing photosynthesis.4,5 We report that VHA is localized around the chloroplasts of centric diatoms and that VHA significantly contributes to their photosynthesis across a wide range of oceanic irradiances. Similar results in a pennate diatom, dinoflagellate, and coccolithophore, but not green or red microalgae, imply the co-option of phagocytic VHA activity into a carbon-concentrating mechanism (CCM) is common to secondary endosymbiotic phytoplankton. Furthermore, analogous mechanisms in extant photosymbiotic marine invertebrates6,7,8 provide functional evidence for an adaptive advantage throughout the transition from endosymbiosis to symbiogenesis. Based on the contribution of diatoms to ocean biogeochemical cycles, VHA-mediated enhancement of photosynthesis contributes at least 3.5 Gtons of fixed carbon per year (or 7% of primary production in the ocean), providing an example of a symbiosis-derived evolutionary innovation with global environmental implications.

We present unresolved questions in plant abiotic stress biology as posed by 15 research groups with expertise spanning eco-physiology to cell and molecular biology. Common themes of these questions include the need to better understand how plants detect water availability, temperature, salinity, and rising carbon dioxide (CO2) levels; how environmental signals interface with endogenous signaling and development (e.g. circadian clock and flowering time); and how this integrated signaling controls downstream responses (e.g. stomatal regulation, proline metabolism, and growth versus defense balance). The plasma membrane comes up frequently as a site of key signaling and transport events (e.g. mechanosensing and lipid-derived signaling, aquaporins). Adaptation to water extremes and rising CO2 affects hydraulic architecture and transpiration, as well as root and shoot growth and morphology, in ways not fully understood. Environmental adaptation involves tradeoffs that limit ecological distribution and crop resilience in the face of changing and increasingly unpredictable environments. Exploration of plant diversity within and among species can help us know which of these tradeoffs represent fundamental limits and which ones can be circumvented by bringing new trait combinations together. Better defining what constitutes beneficial stress resistance in different contexts and making connections between genes and phenotypes, and between laboratory and field observations, are overarching challenges.

Food waste is a dominant organic constituent of landfills, and a large global source of greenhouse gases. Composting food waste presents a potential opportunity for emissions reduction, but data on whole pile, commercial-scale emissions and the associated biogeochemical drivers are lacking. We used a non-invasive micrometeorological mass balance approach optimized for three-dimensional commercial-scale windrow compost piles to measure methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) emissions continuously during food waste composting. Greenhouse gas flux measurements were complemented with continuous oxygen (O2) and temperature sensors and intensive sampling for biogeochemical processes. Emission factors (EF) ranged from 6.6 to 8.8 kg CH4-C/Mg wet food waste and were driven primarily by low redox and watering events. Composting resulted in low N2O emissions (0.01 kg N2O-N/Mg wet food waste). The overall EF value (CH4 + N2O) for food waste composting was 926 kgCO2e/Mg of dry food waste. Composting emissions were 38-84% lower than equivalent landfilling fluxes with a potential net minimum savings of 1.4 MMT CO2e for California by year 2025. Our results suggest that food waste composting can help mitigate emissions. Increased turning during the thermophilic phase and less watering overall could potentially further lower emissions.

Many challenges related to carbon-dioxide ([Formula: see text]) sequestration in subsurface rock are linked to the injection of fluids through induced or existing fracture networks and how these fluids are altered through geochemical interactions. Here, we demonstrate that fluid mixing and carbonate mineral distributions in fractures are controlled by gravity-driven chemical dynamics. Using optical imaging and numerical simulations, we show that a density contrast between two miscible fluids causes the formation of a low-density fluid runlet that increases in areal extent as the fracture inclination decreases from 90[Formula: see text] (vertical fracture plane) to 30[Formula: see text]. The runlet is sustained over time and the stability of the runlet is controlled by the gravity-driven formation of 3D vortices that arise in a laminar flow regime. When homogeneous precipitation was induced, calcium carbonate covered the entire surface for horizontal fractures (0[Formula: see text]). However, for fracture inclinations greater than 10[Formula: see text], the runlet formation limited the areal extent of the precipitation to less than 15% of the fracture surface. These insights suggest that the ability to sequester [Formula: see text] through mineralization along fractures will depend on the fracture orientation relative to gravity, with horizontal fractures more likely to seal uniformly.

Enhanced rock weathering (ERW) in soils is a promising carbon removal technology, but the realistically achievable efficiency, controlled primarily by in situ weathering rates of the applied rocks, is highly uncertain. Here we explored the impacts of coupled biogeochemical and transport processes and a set of primary environmental and operational controls, using forsterite as a proxy mineral in soils and a multiphase multi-component reactive transport model considering microbe-mediated reactions. For a onetime forsterite application of ~ 16 kg/m2, complete weathering within five years can be achieved, giving an equivalent carbon removal rate of ~ 2.3 kgCO2/m2/yr. However, the rate is highly variable based on site-specific conditions. We showed that the in situ weathering rate can be enhanced by conditions and operations that maintain high CO2 availability via effective transport of atmospheric CO2 (e.g. in well-drained soils) and/or sufficient biogenic CO2 supply (e.g. stimulated plant-microbe processes). Our results further highlight that the effect of increasing surface area on weathering rate can be significant-so that the energy penalty of reducing the grain size may be justified-only when CO2 supply is nonlimiting. Therefore, for ERW practices to be effective, siting and engineering design (e.g. optimal grain size) need to be co-optimized.

Carbon fixation is the process by which CO2 is converted from a gas into biomass. The Calvin-Benson-Bassham cycle (CBB) is the dominant carbon-consuming pathway on Earth, driving >99.5% of the ∼120 billion tons of carbon that are converted to sugar by plants, algae, and cyanobacteria. The carboxylase enzyme in the CBB, ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco), fixes one CO2 molecule per turn of the cycle into bioavailable sugars. Despite being critical to the assimilation of carbon, rubisco's kinetic rate is not very fast, limiting flux through the pathway. This bottleneck presents a paradox: Why has rubisco not evolved to be a better catalyst? Many hypothesize that the catalytic mechanism of rubisco is subject to one or more trade-offs and that rubisco variants have been optimized for their native physiological environment. Here, we review the evolution and biochemistry of rubisco through the lens of structure and mechanism in order to understand what trade-offs limit its improvement. We also review the many attempts to improve rubisco itself and thereby promote plant growth.