Decrease Carbon Dioxide Research Articles

Increasing the efficiency of bioreactor operation for cultivation of methane-oxidizing bacteria under conditions of decreasing carbon dioxide concentration in the cultural liquid

Objectives. The work set out to develop a bioreactor that incorporates a carbon dioxide removal unit within the apparatus gas phase, which is capable of operating without the need for supplementary compression apparatus. As part of testing the developed equipment in order to ascertain its capacity for enhanced biomass production, the principal fermentation system parameters that facilitate the optimal bioreactor productivity in conditions of carbon dioxide removal from the apparatus gas phase were identified.Methods. A series of tests were conducted on the fermentation unit with the objective of controlling the oxygen and carbon dioxide content in the gas phase of the bioreactor. This was achieved using an in-line gas analyzer fitted with electrochemical sensors. The oxygen and carbon dioxide content in the gas phase was determined by means of gas chromatography. The oxygen and natural gas flow rates were determined using a thermal electronic flow controller equipped with thermoresistive elements. The oxygen content of the cultural liquid was determined by means of an optical oxygen sensor with integrated transducer. The pH level in the bioreactor was monitored and maintained using an electrochemical pH sensor.Results. The efficacy of the newly devised jet-type bioreactor design, which permits the incorporation of a carbon dioxide removal unit into the fermentation system without requiring supplementary compression apparatus, was evaluated through experimentation. The system was tested with the carbon dioxide removal unit included in the design, resulting in a 64% increase in bioreactor productivity and a 18% reduction in oxygen consumption as a component of the gas supply.Conclusions. The operational parameters of a technological bioreactor that facilitate a stable continuous process of bacterial cultivation were identified.

Tailored Carbon Dots in Solar Energy Conversion Schemes

Addressing the dual challenge of meeting the world's escalating energy needs while simultaneously decreasing carbon dioxide emissions has emerged as a pivotal issue in the new millennium. The Statistical Review of World Energy's latest report by British Petroleum Company plc reveals that global power consumption was around 18.9 terawatts (TW) in 2021, with projections estimating a surge to 30 TW by 2050. In stark contrast, solar radiation delivers a 120,000 TW to the Earth's surface, a quantity that exceeds the projected energy consumption of 2050 by 4,000 times. Efficiently harnessing and storing this immense solar energy is increasingly seen as a viable route towards a sustainable energy network. A promising solution lies in carbon-based systems. Carbon dots (CDs), an emerging class of nanomaterials, show great potential in this field. These can be synthesized through scalable methods using various carbon and nitrogen precursors, including waste, making them both cost-effective and recyclable. CDs offer a range of photophysical properties, such as variable photoluminescence and the generation of spin-active states. Furthermore, CDs are biocompatible, non-toxic, and environmentally friendly. Unlike traditional binary semiconductors, their photocatalytic attributes can be finely adjusted using a variety of organic chemistry functionalization techniques. While CDs have primarily been optimized for PL properties, their application in metal-free photocatalysis remains largely untapped. Major obstacles are the large structural diversity and complex multicomponent arrangement of CDs, along with the high variability of their photoactive centers, presenting a unique challenge. The ongoing controversy over the exact CDs structure, further compounded by a limited understanding of how this structure influences their photophysical properties, significantly hinders advancements in CDs design. This challenge significantly hampers progress in the development of more effective CDs for solar-driven water-splitting, underscoring the urgent need for increased collaboration between experimentalists and theoreticians now more than ever. In this contribution, we delve into the current understanding of photocatalytically active CD-based systems. The focus is set on model systems that feature no co-catalysts. We explore the role of CDs, shed light on the structure-activity relationship and detail photon- and charge-management in the excited state. Additionally, we share our insights on the potential opportunities that emerge from a deeper comprehension of CDs.

The impact of Tanreqing injection on mucus hypersecretion and cough in bronchiectasis: A meta-analysis of randomized controlled trials.

Bronchiectasis clinically manifests airway mucus hypersecretion as mucopurulent sputum production and chronic cough. In the past decade, Tanreqing injection (TRQ) has been often used in clinical practice as an add-on treatment for bronchiectasis in China. Several in vivo studies have indicated that TRQ is effective in improving sputum expectoration and cough in acute exacerbation of bronchiectasis but results of individual studies are inconsistent. Therefore, systematically and critically evaluating the effectiveness and safety of TRQ on mucus hypersecretion and cough in bronchiectasis is necessary. Randomized controlled trials examining the treatment of bronchiectasis with TRQ were systematically searched from databases including PubMed, Cochrane Library, Embase, Web of Science, Chinese National Knowledge Infrastructure, Vip Information Database, Wanfang data, and Chinese Biomedical Literature Database, based on a preregistered protocol and adhering to Cochrane methods. Pertinent data were taken out from the included studies and a methodological quality assessment was done. R language (version 4.4.1) was used to perform the meta-analysis. Twenty randomized controlled trials involving 1544 patients were analyzed. The results demonstrated that TRQ significantly improved mucus hypersecretion, shortened the duration of cough and phlegm, reduced symptom scores, and enhanced both forced expiratory volume in 1 second and forced vital capacity. Additionally, TRQ effectively lowered inflammatory markers, including C-reactive protein, procalcitonin, white blood cell count, neutrophil count, interleukin-6, and tumor necrosis factor-alpha. Moreover, TRQ increased the partial pressure of oxygen and decreased carbon dioxide pressure. The findings suggest that TRQ positively impacts mucus hypersecretion and mucociliary clearance, leading to improvements in sputum production and cough during bronchiectasis exacerbations, without increasing the risk of adverse effects. TRQ may be considered a viable option for managing bronchiectasis and could serve as a novel mucus-modifying agent.

Toward Environmental Sustainability in Africa: The Impact of Financial Technology, Human Development, and Renewable Energy Consumption Across Income Groups

ABSTRACTThe United Nation's Sustainable Development Goal 13 (“Climate Action”) aims to address the issues of global warming and climate change, primarily caused by greenhouse gas emissions. This study examines the impacts of financial technology, human development, economic growth, and renewable energy consumption on environmental quality from 2013 to 2019 in African nations classified into different income groups. Using the method of moments quantile regression (MMQR) technique, results show that economic growth and human development (renewable energy consumption and financial technology) increase (decrease) carbon dioxide emissions in the long run. These imply that in the absence of sustainable practices, pursuing economic growth and human development could degrade the environment, while transitioning to renewable energy and promoting fintech could improve environmental quality. This study makes five major scientific contributions in terms of research question (unique combination of variables), sample (carbon emission‐financial technology nexus in Africa), proxy for financial technology (“credit flows by fintech and big tech companies to GDP (%)”), MMQR estimation technique (for the first time in this context), and comparative analysis based on income‐group classification. This study recommends the implementation of sustainable development frameworks, the adoption of green technologies, the transition from nonrenewable to renewable energy sources, the widespread education and awareness on environmental effects, and the encouragement of sustainable fintech solutions to help African countries attain sustainable economic growth and human development while reducing their carbon footprints.

Integrated Techno-Environmental Analysis of Finely Ground Silica Sand in Sustainable Mortar Production

The environmental impacts of cement production are becoming more urgent concerns. This study examined the mechanical characteristics of cement when it is partially replaced with finely crushed sand. The experimental program consisted of three different levels of sand fineness of 459 m2/kg, 497 m2/kg, and 543 m2/kg, as well as four substitution ratios of 10%, 20%, 30%, and 40%. A total of thirteen combinations were formulated and then evaluated. The results demonstrated that increasing sand fineness from 459 m2/kg to 543 m2/kg substantially impacted the compressive strength (CS), increasing it by up to 30%, and increasing the substitution ratio from 10% to 40% reduced the mechanical strength by roughly 40%. An extensive techno-environmental evaluation showed that replacing cement with finely crushed sand is technically feasible and environmentally advantageous. This technique can decrease carbon dioxide (CO2) emissions by around 40%, emphasizing its ecological benefits and coinciding with worldwide initiatives to decrease the environmental impact of construction materials. In summary, this study demonstrates the advantages of improving the mechanical characteristics of cement while minimizing its ecological footprint. It suggests that finely crushed sand can be used as a sustainable alternative in cement manufacturing, promoting the use of more environmentally friendly construction methods.

Improvements in maize N recommendations decreased carbon dioxide equivalence without sacrificing yield

AbstractGlobally, agricultural scientists are challenged with creating, testing, and validating climate‐smart nutrient strategies that reduce greenhouse gas emissions while increasing food security. This study determined maize (Zea mays L.) N recommendations and bias for N‐rate studies conducted in South Dakota using models created for western Minnesota, Iowa, Eastern North Dakota, Nebraska, and South Dakota. From 2019 to 2021, 16 N rate studies were conducted in long‐term no‐tillage (>6 years) fields located in South Dakota. In the randomized block replicated study, the soils were mollisols that were derived in a semi‐arid frigid environment. The economic optimum N rates were calculated using four fertilizer‐to‐maize grain price ratios (4.11, 5.48, 6.85, and 8.23 [$ (kg N)−1] [$ (kg grain)−1]−1). Analysis showed that reducing the yield goal coefficient used in the South Dakota model from 21.4 to 17.9 kg N (Mg grain)−1 reduced the recommended N rate but did not reduce yield. The reduced yield goal coefficient that considered the fertilizer‐to‐maize price ratio also reduced model root mean square error (RMSE), bias, and the estimated partial carbon dioxide equivalence (CO2e) by at least 18%. Nitrogen recommendation models developed for western Minnesota, Iowa, and South Dakota had similar RMSE, bias, and fertilizer recommendations, and adjusting the recommendation based on expected fertilizer cost and maize selling price improved accuracy. This study suggests that yield was not sacrificed by reducing the coefficients from 21.4 to 17.9 kg N (Mg grain)−1 and that recommendations are improved by considering the fertilizer‐to‐maize grain price ratio.

Water Conservation Practices and Nitrogen Fertility for the Reduction of Greenhouse Gas Emissions from Creeping Bentgrass Putting Greens

Irrigation practices that conserve water use have the potential to reduce greenhouse gas (GHG) emissions but may adversely affect turfgrass appearance. The purpose of this study was to identify irrigation practices and N fertilizers that will decrease carbon dioxide (CO2), methane (CH4,), and nitrous oxide (N2O) emissions while evaluating turfgrass color and quality. In both years, supplemental rainfall (SRF) soil moisture content was higher than business as usual (BAU) irrigation and syringing (SYR). Higher soil moisture led to increased fluxes in both soil CO2 and soil N2O. In 2017, the SRF fluxed lower soil CO2 as soil moisture reached levels that restricted respiration. Soil moisture was also an important predictor of soil N2O flux with BAU and SRF having higher soil N2O fluxes. SRF produced the greenest turf from May to July, whereas SRY and SRF produced the greenest turf from August to October in 2016. Both BAU and SRF had the greenest turf in 2017. BAU had the highest turfgrass quality ratings in 2016 followed by SRF and SRY, respectively, whereas in 2017 SRF and SRY had higher turfgrass quality ratings. When adopting water conservation practices to reduce GHG emissions, soil moisture content and site-specific rainfall should be closely monitored to prevent overwatering.

The dynamic nexus between economic growth, renewable energy use, urbanization, industrialization, tourism, green supply chain management, and CO2

Since 2012, China has pursued an “ecological civilization” policy to promote green energy, increase environmental protection, and transition to more sustainable growth models. The complicated positive trends in energy consumption, more sustainable economic growth, and ecological management are obscured by China's persistent, significant dependence on fossil fuels, particularly coal. The study aims to analyze how renewable energy use in China affects carbon dioxide emissions and how those impacts change over time, as well as urbanization, industrialization, tourism, and green supply chain management. The DOLS dynamic system method used historical data from 1995 to 2022. The DOLS results show a positive and statistically significant economic growth coefficient in the long term, suggesting that an increase of only one percent in CO₂ emissions rise would be proportional to a surge in economic growth.Furthermore, using renewable energy sources correlates with long-term sustainability negatively and significantly. The results show reducing CO₂ emissions and boosting renewable energy use by 1 %. Furthermore, the long-run coefficients for industrialization and urbanization are positive and statistically significant, indicating that a 1 % increase in either component results in a comparable increase in CO₂ emissions. Sustainable logistics and tourism have negative and statistically significant coefficients, meaning that a one percent increase will gradually decrease carbon dioxide emissions. The estimated findings hold up when using other estimators, such as the commonly used co-integrating regression (CCR) strategy and fully modified least squares (FMOLS). When Granger causality is coupled, the test also catches the variables' causal link. test. To achieve environmental sustainability, the essay suggests using robust regulatory policy tools to curb ecological deterioration.

A Comparison of a Three Blade and Five Blade Wind Turbine in Terms of the Mechanical Properties Using the Q-Blade Software

يمكن لتوربينات الرياح المنتشرة في مزارع الرياح على نطاق المرافق أن تدعم تلبية رغبات الطاقة المستقبلية وتقليل انبعاثات ثاني أكسيد الكربون عن طريق تقليل متطلبات الطاقة من الوقود الأحفوري. مع ارتفاع درجة حرارة الهواء على مدار اليوم، تزداد سرعة الرياح بسبب تدرجات درجة الحرارة، والتي تنتج تدرجًا في الكثافة / الضغط، مما يؤدي إلى حركة الهواء التي تواجهها توربينات الرياح. اعتمادًا على تضاريس الأرض، يمكن أن تواجه الرياح وتوجه في الوديان بين التلال وفوقها حيث تتدفق وتتبع منحنيات الأرض. تنتج هذه التضاريس زيادة في سرعة الرياح في القمم والتلال. في هذا العمل، تم تصميم شفرة دوار توربينات الرياح الأفقية الصغيرة للعمل في ظل سرعة الرياح المنخفضة، باستخدام برنامج (Q-Blade). استنادًا إلى نظرية عنصر الشفرة (BEM). مع الجنيح NACA3712. تم استخدام دوار ثلاثي الشفرات ودوار بخمس شفرات بناءً على نوع التوربين وحجم الدوار لتوليد الطاقة الميكانيكية من طاقة الرياح. تم إجراء مقارنة وتحليل قوة التوربين ومعامل القدرة ومعامل عزم الدوران عند سرعة رياح منخفضة ((1m/s-8m/s وتم الحصول على نتائج دقيقة للغاية. وجد أن أفضل أداء يمكن أن يعمل فيه دوار توربيني ثلاثي الشفرات بقدرة توربينية تبلغ (955W) كما تم الحصول على قدرة التوربين ((582W للدوار خماسي الشفرات. وجد أن تصميم توربينة رياح أفقية صغيرة بخمس ريش أفضل من التوربين بثلاث ريش ومناسب للعمل في المناطق ذات سرعة الرياح المنخفضة وبكفاءة عالية مقارنة بحجم التوربين.

A critical review on synthesis and application aspect of venturing the thermophysical properties of hybrid nanofluid for enhanced heat transfer processes

Recently, nanofluids (NFs) have gathered significant attention among researchers due to their varied properties, which can be made per the requirements. NFs, created by infusing nanoparticles into a base-fluid, enhance their fundamental properties. A hybrid nanofluid (HNF) is a nanofluid (NF) containing different types of nanoparticles, and it is being studied for its customizable properties. Recently, researchers delved into the applications regarding HNFs, particularly in cases relating to heat transfer (HT). This study analyzes HNFs’ preparation methods and thermophysical properties, giving more importance to their applications in HT, including heat-exchange, solar thermal, and cooling systems. Considering stability, the two-step synthesis method is preferred over the single-step method. Multiple research efforts have led to the development of a fluid that possesses superior HT capabilities compared to the base-fluid. However, while bettering HT, an increase in volume concentration (VC) also raised challenges such as increased viscosity and pressure drop, particularly in porous media, necessitating additional pumping power. The use of turbulators and other configurations, along with HNF in systems like parabolic trough solar collectors (PTSCs), enhances solar thermal systems (STSs) by improving their HT capabilities. An advantageous use of EG-based multiwalled carbon nanotubes (MWCNTs) NF in solar collectors (SCs) is their ability to increase thermal efficiency and decrease carbon dioxide emissions, making them an attractive choice for use in SCs. Researchers face significant challenges in determining the ideal composition and concentration of nanoparticles in HNFs to attain optimal HT without causing excessive viscosity that could impede practical usability. Specifically, this study examines the distinctive thermophysical characteristics of HNFs that substantially improve their efficacy in HT applications.

Peritoneal Infusion of Oxygen Microbubbles Alters the Metabolomic Profile of the Lung and Spleen in Acute Hypoxic Exposure.

Administration of oxygen microbubbles (OMBs) has been shown to increase oxygen and decrease carbon dioxide in systemic circulation, as well as reduce lung inflammation and promote survival in preclinical models of hypoxia caused by lung injury. However, their impact on microenvironmental oxygenation remains unexplored. Herein, we investigated the effects of intraperitoneal administration of OMBs in anesthetized rats exposed to hypoxic ventilation (FiO2 = 0.14). Blood oxygenation and hemodynamics were evaluated over a 2 h time frame, and then organ and tissue samples were collected for hypoxic and metabolic analyses. Data showed that OMBs improved blood SaO2 (~14%) and alleviated tissue hypoxia within the microenvironment of the kidney and intestine at 2 h of hypoxia. Metabolomic analysis revealed OMBs induced metabolic differences in the cecum, liver, kidney, heart, red blood cells and plasma. Within the spleen and lung, principal component analysis showed a metabolic phenotype more comparable to the normoxic group than the hypoxic group. In the spleen, this shift was characterized by reduced levels of fatty acids and 2-hydroxygluterate, alongside increased expression of antioxidant enzymes such as glutathione and hypoxanthine. Interestingly, there was also a shuttle effect within the metabolism of the spleen from the tricarboxylic acid cycle to the glycolysis and pentose phosphate pathways. In the lung, metabolomic analysis revealed upregulation of phosphatidylethanolamine and phosphatidylcholine synthesis, indicating a potential indirect mechanism through which OMB administration may improve lung surfactant secretion and prevent alveolar collapse. In addition, cell-protective purine salvage was increased within the lung. In summary, oxygenation with intraperitoneal OMBs improves systemic blood and local tissue oxygenation, thereby shifting metabolomic profiles of the lung and spleen toward a healthier normoxic state.

Enhancing sustainability in sewage treatment: A least squares support vector regression-based modeling approach for optimizing regeneration conditions of iFeCu

Nanoparticles in wastewater treatment offer sustainable, efficient removal of persistent pollutants, with minimal resource usage and reusability. This study examines the reusability of immobilized iron‑copper nanoparticles (iFeCu) for sewage treatment. The effect of the regeneration condition of iFeCu including the regeneration time and temperature on the performance of iFeCu for sewage treatment was investigated. Moreover, a soft sensor model, namely principal component analysis discrimination analysis ensemble least squares support vector regression (PCA-DA-E-LSSVR) model was developed to predict the performance of iFeCu, and an online performance of the model was studied to evaluate its accuracy. Investigating regeneration conditions like time and temperature, it was found that iFeCu regenerated in 1 mol (M) sodium carbonate (Na2CO3) at 40 °C for 5 h performed comparably to that regenerated at 60 °C for 15 h. Higher regeneration temperatures (>40 °C) decreased carbon dioxide and monoxide emissions but reduced ammonia (NH3) removal by ∼22 %. Shorter regeneration times (<5 h) decreased Na2CO3-iFeCu interaction, leading to an ∼11 % NH3 removal reduction. The correlation coefficient, R2 value of 0.8514 was obtained for the proposed PCA-DA-E-LSSVR model. Overall, the developed model well-fits the nonlinear data in sewage treatment and provides acceptable ranges of online performance results.

What are the best alternatives for sustainability? A rationalization theme for natural resource depletion and technical innovation

There has been a global upsurge in discussions about environmental sustainability. To fight climate change and attain long-term economic expansion, decreasing carbon dioxide (CO2) emissions is crucial. In addition, these issues take center stage in the Next 11 economies due to the scarcity and overexploitation of natural resources, leading to increased carbon emissions. Advancements in technology are essential to achieving sustainable development. Making technical advances is the only way to guarantee that economic growth at lower environmental cost. In this piece, we'll look at how technological progress and the exhaustion of natural resources have affected CO2 emissions. The research examines the interplay between digitization, human capital, and the rule of law, among other aspects. Researchers analyzed panel series data for the next 11 economies from 2003 to 2022. However, the current study utilizes robust estimators to obtain the desired objective of study. Investigated outcomes describe, digitalization, technical innovation, and human resources hurt sustainability level, although the rule of law and the depletion of natural resources have a beneficial effect. The selected and other rising economies may use the predicted findings to inform policy decisions on how to best go forward with sustainable development.

Investigating Methane, Carbon Dioxide, Ammonia, and Hydrogen Sulphide Content in Agricultural Waste during Biogas Production

The agricultural industry produces a substantial quantity of organic waste, and finding a suitable method for disposing of this highly biodegradable solid waste is a difficult task. The utilisation of anaerobic digestion for agricultural waste is a viable technological solution for both renewable energy production (biogas) and waste treatment. The primary objective of the study was to assess the composition of biogas, namely the percentages of methane, carbon dioxide, ammonia, and hydrogen sulphide. Additionally, the study aimed to quantify the amount of biogas produced and determine the methane yield (measured in NmL/g VS) from different agricultural substrates. The biochemical methane potential (BMP) measurements were conducted in triplicate using the BPC Instruments AMPTS II instrument. The substrates utilised in the investigation were chosen based on their accessibility. The substrates used in this study comprise cattle manure, chicken manure, pig manure, tomato plants, tomatoes, cabbage, mixed fruits, mixed vegetables, dog food, and a co-digestion of mixed vegetables, fruits, and dog food (MVMFDF). Prior to the cleaning process, the makeup of the biogas was assessed using the BIOGAS 5000, a Geotech Analyser. The AMPTS II flow cell automatically monitored and recorded the volume of bio-methane produced after the cleaning stage. The data were examined using the Minitab-17 software. The co-digestion of mixed vegetables, mixed fruits, and dog food (MVMFDF) resulted in the highest methane level of 77.4%, followed by mixed fruits at 76.6%, pig manure at 72.57%, and mixed vegetables at 70.1%. The chicken manure exhibited the greatest levels of ammonia (98.0 ppm) and hydrogen sulphide (589 ppm). Chicken manure had the highest hydrogen sulphide level, followed by pig manure (540 ppm), tomato plants (485 ppm), mixed fruits (250 ppm), and MVMFDF (208 ppm). Ultimately, the makeup of biogas is greatly affected by the unique qualities of each substrate. Substrates containing elevated quantities of hydrogen sulphide, such as chicken manure, require the process of biogas scrubbing. This is because they contain substantial amounts of ammonia and hydrogen sulphide, which can cause corrosion to the equipment in biogas plants. This emphasises the crucial need to meticulously choose substrates, with a specific focus on their organic composition and their capacity to generate elevated methane levels while minimising contaminants. Substrates with a high organic content, such as agricultural waste, are optimal for maximising the production of methane. Furthermore, the implementation of biogas scrubbing procedures is essential for efficiently decreasing carbon dioxide and hydrogen sulphide levels in biogas. By considering and tackling these problems, the effectiveness of biogas generation can be enhanced and its ecological consequences alleviated. This strategy facilitates the advancement of biogas as a sustainable energy source, hence contributing to the attainment of sustainable development goals (SDGs).

Biofuel supply chain planning and circular business model innovation at wastewater treatment plants: The case of biomethane production

Advanced biofuels, such as biomethane, could contribute to environmental sustainability in increasingly interrelated sectors, such as energy and waste management. Accordingly, innovative biomethane production technologies are argued to be the enablers of circular and waste-to-energy concepts, for example, at wastewater treatment plants (WWTPs). Nevertheless, their integration into biofuel supply chain (BSC) research is overlooked from a circular business model innovation (BMI) perspective. This study aims to address this research gap by focusing on an innovative biomethane production approach (power-to-gas, P2G) and related circular business model innovation opportunities in the context of WWTPs. We carried out lab-scale research and a case study at a mid-sized European WWTP to establish an empirical basis for large-scale techno-economic calculations. Despite the explored technological opportunity to increase advanced biofuel supply and decrease carbon dioxide emissions at WWTPs, current market risk levels challenge the economic prospects of the system concept. These empirical results demonstrate the necessity of policy interventions in different combinations (e.g., investment support, favourable taxation, feed-in tariffs). This study is one of the first to combine technological and business modelling aspects to support BSC planning, and supplement optimization-focused BSC research with explorative techno-economic analyses based on empirical data.

Sustainability assessment and mechanical characteristics of high strength concrete blended with marble dust powder and wheat straw ash as cementitious materials by using RSM modelling

Research into environmentally favorable alternatives to conventional concrete, such as reengineering techniques and the recycling of industrial and agricultural waste, has increased dramatically over the past decade. This research intended to examine the potential benefits of utilizing wheat straw ash (WSA) and marble dust powder (MDP) as supplementary cementitious materials (SCM) in high-strength concrete (HSC). The intention is to decrease carbon dioxide emissions and the amount of Portland cement (PC) required. Concrete formulations containing 0%, 15%, 20%, 30%, and 40% by weight of MDP and WSA as SCM, respectively, were evaluated by using response surface methodology (RSM) modelling for multi-objective optimization. This research assessed the environmental ramifications of employing WSA and MDP as SCM in HSC. Specifically, it examined the impacts on embodied carbon and eco-strength efficiency. Cubical specimens underwent a series of tests to attain the desirable compressive strength of approximately 60 MPa after a period of 28 days. The workability of green concrete decreased as the proportion of WSA and MDP used as SCM increased, according to the study. The optimum compressive strength, flexural strength, splitting tensile strength, and modulus of elasticity of HSC was recorded by 68 MPa, 5.98 MPa, 4.25 MPa, and 40 GPa, at 15% of SCM (composed of 10% WSA and 5% MDP) at 28 days respectively. Using ANOVA, response prediction models were validated and developed with a confidence level of 95%. In summary, the increased application of 20% WSA and 20% MDP as SCM in concrete leads to a 31.64% reduction in the carbon footprint of the material.

Unintended environmental gains: The impact of China–Europe Railway Express on carbon dioxide emissions in China

Climate change is a major environmental issue, while reducing carbon dioxide emissions is viewed as a vital measure against global warming. The CHINA RAILWAY Express (CRE) could attract or foster new export-oriented industries by generating new profitable export opportunities and enhancing access to European markets. This study focused on the unintended effect of the CRE policy on carbon dioxide emissions reduction, which stems from its promotion of industry development. We used the synthetic difference-in-differences approach to derive reliable estimation of the CRE’s unintended low-carbon effect. After controlling for the influence of other emission sectors and other low-carbon policies, the estimated results indicate that the CRE only reduced carbon dioxide emissions in the 12 cities with regular CRE services. The unintended policy effect decreased carbon dioxide emissions, on average, by 9.18%. Further heterogeneous analysis shows that the CRE’s effect is positively correlated with the numbers of CRE trains. Moreover, the CRE has a heterogeneous impact on high-carbon and low-carbon sectors. Because the CRE can promote the exports of low-carbon sectors to Europe rather than those of high-carbon sectors, the CRE has a prominent impact on reducing average carbon dioxide emissions and improving the industrial structure. Formal mechanism analysis confirms that the impact of the CRE on carbon dioxide emissions actually occurs through the mechanism of industrial structure upgrading. Our results reveal the CRE’s unintended environmental gains and offer insight for governments that hope to simultaneously reduce carbon dioxide emissions and promote economic growth.

Effect Analysis of China's Carbon Emission Trading Pilot Policy on Carbon Emission Control

Many countries have achieved a fundamental consensus to decrease carbon dioxide emissions in order to address environmental and climate issues. China, as the foremost energy consumer and carbon emitter globally, has significantly contributed to the exacerbation of greenhouse gas issues. The most effective method for lowering carbon emissions is through the trade of carbon emissions. In 2011, China began the process of implementing pilot projects for pricing carbon emissions as a means of addressing environmental and climate-related issues. This study use the literature review approach to examine the current state of China's carbon emission trading pilot policies on carbon emission management. It also analyzes the technical and economic impacts of these pilot policies in comparison to non-pilot carbon emission trading policies. The objective of this study is to propose recommendations for the implementation of the national carbon emission trading market in 2021.

Understanding the nonlinear effect of digital technology development on CO2 reduction

AbstractDigital technology, including advancements in artificial intelligence, the Internet of Things, and data analytics, has the potential to revolutionize tackling the problem of carbon dioxide emissions and achieving sustainable development. The paper aims at checking the nature of the impact of digital technology development on carbon dioxide reduction for the EU countries in 2013–2020. The study applies the following methods: entropy methods, panel‐corrected standard error, and feasible generalized least squares. The digital technology development index enabled the classification of all the EU countries into two distinct groups: High Digital Technology Development and Moderate/Lower Digital Technology Development. The findings confirm that digital technology development has a significant impact on decreasing carbon dioxide emissions. In the first stage, the growth of digital technology causes a faster decrease in carbon dioxide emissions. However, beyond a certain threshold, the further improvement of digital technology results in diminishing marginal benefits of CO2 emissions reduction. Thus, the EU government should catalyze the extension of digital technologies among all sectors and levels. In addition, it requires enhancing digital literacy of the society and local authorities.

Quantifying and evaluating strategies to decrease carbon dioxide emissions generated from tourism to Yellowstone National Park

The tourism industry needs strategies to reduce emissions and hasten the achievement of global carbon dioxide (CO2) emission reduction targets. Using a case study approach, we estimated CO2 emissions related to park tourism in Yellowstone National Park (USA) generated from transit to and from the park, transit within the park, accommodations, and park operations. Results indicate tourism to Yellowstone National Park produces an estimated 1.03 megaton (1.03 billion kg) of CO2-equivalent emissions annually, with an average of 479 kg CO2 per visitor. Almost 90% of these emissions were attributable to transit to and from the destination, while 5% were from transit within the park, 4% from overnight accommodations, and about 1% from other park operations (e.g., visitor centers, museums, shops, restaurants, etc.). Visitors who fly only made up about 35% of all visitors, but produced 72% of the emissions related to transit to and from the park. Future scenarios that alter transit to and from the park can reduce emissions the most; this includes a greater proportion of local or regional visitors, fewer visitors flying, and increased fuel efficiency of vehicles. The method developed in this work, and applied specifically to Yellowstone National Park, can be adopted elsewhere and used to help decision makers evaluate the effectiveness of potential emission reduction strategies.