Decrease Greenhouse Gas Emissions Research Articles

Integrating fiber with new cement trends to create a greener future for sustainable concrete

The need for innovation in the construction sector is increasingly pressing, propelled by rising environmental issues and the ongoing quest for structural efficiency. This study investigates the transformational potential of fiber-reinforced concrete (FRC), analyzing its ability to improve mechanical performance and promote environmental sustainability. By using diverse fibers, including natural, synthetic, and industrial waste fibers, FRC enhances qualities like as tensile strength, fracture resistance, and durability while promoting more sustainable building techniques. This research carefully explores current improvements in the processing and handling of various fibers and assesses their effects when integrated into concrete. Particular emphasis is placed on the use of recovered industrial by-products, including slag, fly ash, and recycled plastics, in conjunction with natural fibers such as bamboo, kenaf, and flax. These materials are recognized for both augmenting the structural integrity of concrete and substantially decreasing the carbon footprint of construction by lowering dependence on virgin resources and encouraging the recycling of industrial waste. Experimental investigations and life cycle evaluations were performed to measure the improvements in performance and sustainability provided by FRC. The study results indicate that FRC has enhanced durability and performance attributes, making it a suitable choice for both structural and non-structural applications. Moreover, the incorporation of sustainable fibers has shown a decrease in greenhouse gas emissions, consistent with international sustainability objectives. Nonetheless, the implementation of FRC encounters obstacles pertaining to the inconsistency of fiber characteristics, economic viability, and industrial scalability. Confronting these obstacles via continuous research and interdisciplinary cooperation is essential for the widespread adoption and use of FRC in the construction sector. This study emphasizes the significance of new materials, such as fiber-reinforced concrete, in promoting sustainable building methods, illustrating its potential to profoundly influence the future of construction regarding environmental responsibility and structural efficacy.

Production of Xylitol and Ethanol from Agricultural Wastes and Biotransformation of Phenylacetylcarbinol in Deep Eutectic Solvent

Converting agricultural biomass wastes into bio-chemicals can significantly decrease greenhouse gas emissions and foster global initiatives towards mitigating climate change. This study examined the co-production of xylitol and ethanol from xylose and glucose-rich hydrolysates of corn cob (CC), sugarcane bagasse (SCB), and rice straw (RS) without prior detoxification, using C. magnoliae (C. mag), C. tropicalis (C. trop), and C. guilliermondii (C. guil). A score ranking system based on weighted yields and productivity assessed the best raw material and yeast strain combination. The study revealed that C. mag cultivated on RS hemicellulosic and CC cellulosic media exhibited statistically significant (p ≤ 0.05) superiority in xylitol (272 ± 5) and ethanol 273 ± 3, production. The single-phase emulsion system using frozen-thawed whole cells of CC—C. mag, CC—C. trop, and RS—C. guil was utilized for phenylacetylcarbinol (PAC) biotransformation. Although similar PAC concentration within 14.4–14.7 mM was obtained, the statistically significant higher (p ≤ 0.05) volumetric pyruvate decarboxylase (PDC) activity from C. mag at 360 min was observed by 28.3 ± 1.51%. Consequently, further utilization of CC—C. mag in a two-phase emulsion system (Pi buffer: vegetable oil (Vg. oil) and Pi buffer: deep eutectic solvents (DES)) revealed that Pi buffer: DES medium preserved volumetric PDC activity (54.0 ± 1.2%) statistically significant higher (p ≤ 0.05) than the Pi buffer: Vg. oil system (34.3 ± 1.3%), with no statistically significant difference (p > 0.05) in [PAC]. These findings outlined the sustainable pioneering approach for the co-production of chemicals and reusing the residual yeast cells for PAC biotransformation in the Pi buffer: DES system.

Exploring Alkali Hydroxide Influence on Calcium Titanate Formation for Application in Biodiesel Catalysts

Biodiesel has been recognized as the most widely utilized biofuel around the world due to its significant role in reducing the consumption of crude oil and lowering environmental pollution levels. By serving as a renewable alternative to fossil fuels, bioethanol helps decrease greenhouse gas emissions and contributes to a more sustainable energy future. Traditionally, alkali hydroxides like NaOH and KOH have been mainstays in biodiesel synthesis. However, their overuse can lead to unwanted byproducts and operational complexities. Since calcium titanate can occur at a strong base condition, it presents an alternative avenue worth exploring. In this study, we investigate the influence of alkali hydroxides, namely LiOH, NaOH, and KOH, on the formation of calcium titanate through hydrothermal methods, with varying heating times. We aim to understand how different hydroxides affect the synthesis process and the resultant properties of calcium titanate. We delve into the vibrational properties of Ca‒O‒Ti and Ti‒O bonds using Fourier transform infrared spectroscopy (FTIR), confirming the presence of calcium titanate (JCPDS No.42-0423) through X-ray diffractometry (XRD). This thorough characterization provides insight into the structural integrity and composition of the synthesized materials. Moreover, scanning electron microscopy (SEM) reveals the intriguing cube-like morphology of calcium titanate, offering visual evidence of its unique structure. The fatty acid methyl ester Iimpressively, our results show that calcium titanate synthesized in 7 M NaOH and KOH solutions, heated for 24 hours, emerges as a promising biodiesel catalyst. We observe fatty acid methyl ester provides the percentages of 63.67% and 90.02%, respectively, indicating the catalytic efficacy of these materials in biodiesel production. These findings not only contribute to the understanding of calcium titanate synthesis but also pave the way for a sustainable future in biodiesel production by introducing efficient and eco-friendly catalysts.

Environmental Sustainability Assessment of Tissue Paper Production

The environmental performance of tissue paper varies greatly based on factors such as the type of fibre used as the raw material, the production process and the fuels used to meet the energy requirements. One possible strategy to decrease greenhouse gas emissions in tissue production is the integration of pulp and paper mills and their energy systems at the same site. However, the environmental trade-offs associated with this strategy are still unclear. Therefore, this study aimed (i) to assess for the first time the environmental impacts of tissue paper produced at a typical industrial site in Portugal using slush and market pulp as the main raw material, and (ii) to assess the environmental effects of the integration of bioenergy produced in the pulp mill in tissue production. A life cycle assessment was conducted from cradle to gate using real data from the production of eucalyptus wood, eucalyptus pulp and tissue paper. The results showed that energy consumption in tissue paper production is the main hotspot for most impact categories. When bioenergy is used in tissue production, the environmental impacts decrease by up to 20% for categories other than marine eutrophication and mineral resource scarcity. These results are relevant to support decision making concerning sustainable practices not only for the pulp and paper industry but also for the authorities in charge of defining environmental policies, incentives and tax regulations.

Do’s and Don’ts in Climate Impact Assessment of University Campuses: Towards Responsible, Transparent and Comprehensive Reporting

With the commitment of more and more universities to decrease greenhouse gas emissions, standardizing the modeling is now becoming urgent. To date, published climate-relevant emissions can be based on completely different and incomparable accounting methods, as shown with results between 6 and 2696 t CO2e for the use phase of the same campus. This article aims to identify, compare, and evaluate the different modeling approaches behind this. For this purpose, this article proposes basic attributes of emissions modeling and reporting. Of the three established approaches to emissions accounting, sector logic (territorial carbon accounting) produces the lowest figures. Reporting in accordance with the greenhouse gas protocol, which has become established worldwide, can also shift the responsibility outside the institutional consumer. Life-cycle assessment, instead, essentially includes provision costs triggered by the consumer. The different modeling approaches also overlap with different coverage of emission sources, for which a standard set is being proposed. Such emissions modeling should finally lead to the determination of university-specific climate performances, i.e., the CO2e emissions per capita and per m2 of gross floor area. Infrastructure and procurement expenses must be recorded in addition and converted to an annual average.

Techno economic study of floating solar photovoltaic project in Indonesia using RETscreen

The utilization of solar energy is crucial for the advancement of sustainable power generation on a worldwide scale, driven by environmental concerns and the depletion of fossil fuels. Indonesia's goal is to achieve carbon neutrality by 2060 and it is aggressively advocating for solar energy, which includes the implementation of new methods such as floating photovoltaic (PV) systems. This study evaluates the Techno-Economic Feasibility of Indonesia's Cirata 145 MW floating solar PV project by employing RETScreen technology. The objective is to improve the long-term financial stability, decrease greenhouse gas emissions, and suggest viable choices for improvement. Examining three scenarios that involve alterations in carbon emissions, energy pricing, and loan interest rates demonstrates different levels of project feasibility. The introduction of carbon tax emission pricing has a substantial impact on the feasibility of projects. This study provides useful insights into doing techno-economic feasibility assessments using RETScreen for floating photovoltaic (PV) systems. It demonstrates how modifying parameters can effectively mitigate project risks.

Uncertainty of climate models and policy implications: a European perspective

AbstractIn this paper we show that both climate models and economic models studying the effects of climate change are characterized by high uncertainty. Hence, far reaching policy implications such as the net zero goal lack a definite scientific foundation. Nevertheless, it cannot be excluded that the continued global warming will go along with high damages in the future. Therefore, decreasing greenhouse gas emissions could be justified due to the precautionary motif. However, there are strong signals from non-European economic regions that they definitely put a higher weight on economic growth rather than on greenhouse gas mitigation. The reduction of greenhouse gases in the European Union cause tremendous costs without influencing the climate on earth. Further, these investments do not raise the aggregate stock of productive capital nor do they lead to factor augmenting technical progress. Therefore, the net zero goal of the Green Deal of the European Union is to be seen sceptical.

Exploring the relationship of building area and GHGe: a mitigation strategy?

Abstract Greenhouse gas emissions (GHGe) from new constructions must be reduced to address the climate change crisis. Life cycle assessment (LCA) is widely applied to document the environmental impacts of buildings, often reporting results by dividing the total emissions over the measured building area, such as the gross floor area. The appropriateness of this approach has been debated in the building LCA research community and the construction industry, with concerns about the potential consequence of designing larger buildings to reduce emissions over the buildings’ life cycle and if this entails easier compliance with limit values in regulations. With a large collection of 291 case studies divided into four weight categories, potential correlations between constructing larger areas and GHGe are explored by fitting linear models. The results show that theoretically, GHGe reported per area can be decreased due to increased building area. However, this requires significant increases in area, which realistically results in increased costs, resource use, and related environmental impacts, which is not feasible. Therefore, the findings do not support the notion that interpreting LCA results per square meter encourages the enlargement of buildings to reduce emissions over their life cycle. It should be noted that the study’s conclusions are drawn from the end results of individual LCAs. The potential decrease in GHGe by enlarging the building area during the design process is not possible to derive without involving stakeholders. Thus, this study underlines the need for future research to achieve a nuanced relationship between building size, design choices, and environmental impacts.

Triple impact: Biochar, no-tillage, and cover crops for soil carbon enhancement and climate resilience in soybean farming

With the dissemination of conservation agriculture, no-tillage (NT) and cover crops have widely been adopted globally. However, their effects on greenhouse gas (GHG) emissions are controversial. Biochar is posited to mitigate climate change by increasing carbon (C) sequestration and decreasing GHG emission in soil. To investigate the comprehensive effect of NT, cover crops, and biochar on soil organic carbon (SOC) sequestration and net global warming potential (GWP), a split-split-plot experiment was conducted. The experiment involved various combinations of two tillage methods (NT; Moldboard plowing, MP), two cover crop treatments (Fallow, FA; Rye, RY), and two biochar treatments (with biochar application, WB; no biochar application, NB). NT and RY demonstrated a trend of increasing N2O emission, while WB tended to reduce the N2O emission in NT plots. NT–RY–WB increased the SOC stock (0–30 cm) by 23.2% in 2020 and 30.2% in 2021 compared with MP–FA–NB, indicating that this combination promoted C sequestration. Due to the heightened SOC stock, the net carbon dioxide (CO2) retention effectively compensated the GWP arising from non-CO2 emissions. Consequently, the triple combination of NT, RY and WB positively contributed to a decreased net GWP in the soybean field (−1231 kg CO2 equivalent ha−1 year−1 in 2020 and −2767 kg CO2 equivalent ha−1 year−1 in 2021). These findings highlight the considerable potential of the combined NT–RY–WB for SOC sequestration and net GWP decrease, positioning it as an environmentally beneficial agricultural system for mitigating climate change in Asia’s long-term food production.

Wind power forecasting with metaheuristic-based feature selection and neural networks

Accurate forecasting of wind power generation is crucial for ensuring a stable and efficient energy supply, reducing the environmental impact of energy production, and promoting a cleaner and more sustainable energy supply. Inaccurate forecasts can lead to a mismatch between wind power generation and energy demand, resulting in wasted energy, increased emissions, and reduced grid stability. Therefore, improving the accuracy of wind power generation forecasting is essential for optimizing energy storage and grid management, reducing the reliance on fossil fuels, decreasing greenhouse gas emissions, and promoting a more sustainable energy future. This study proposes an innovative approach to enhance wind power generation forecasting accuracy by leveraging the strengths of metaheuristic algorithms for feature selection and integrating them with Neural Networks (NN). Specifically, five distinct algorithms - Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Ant Colony Optimization (ACO), Teaching-Learning-Based Optimization (TLBO), and Evolutionary Mating Algorithm (EMA) - are integrated with NN model to identify optimal feature subsets from a comprehensive dataset of 18 diverse features. The results show that the GA consistently outperforms other algorithms in selecting the most influential features, leading to improved precision in wind power predictions. Notably, the GA achieves the best root mean square error (RMSE) of 37.1837 and the best mean absolute error (MAE) of 18.6313, outperforming the other algorithms and demonstrating the importance of feature selection in improving the accuracy of wind power forecasting. This innovative framework advances the field of renewable energy forecasting and provides valuable insights into optimizing feature sets for improved predictions across diverse domains.

Enhancing Energy Efficiency in Moroccan Construction through Innovative Materials: A Case Study in a Semiarid Climate

Rising global energy demand has intensified the need for sustainable building practices and reduced energy consumption in the construction sector. This study investigates the energy-saving potential of integrating innovative materials into building wall structures in semiarid climates. Specifically, we examine the combination of thermal insulation made from recycled textile waste and phase change materials (PCMs) in exterior walls. Using the dynamic simulation tool TRNSYS, we analyzed heat transfer through the modified wall assembly under semiarid climate conditions typical of Marrakech, Morocco. Our results show that this “bioclimatic” design significantly impacts cooling loads more than heating demands. The modified building achieved a 52% reduction in summer energy usage compared to a conventional reference building. This energy saving translates to a 39% decrease in greenhouse gas emissions. Importantly, this study confirms that this configuration maintains thermal comfort for occupants, with particular effectiveness during the hot summer months when cooling demands are highest.

On the industrial solar drying of tomatoes in Biskra : A preliminary study

The objective of this study is to carry out a pre-feasibility study of solar industrial drying as a preliminary step before investing in large-scale solar drying projects in Algeria. Our primary goal is to promote the use of industrial solar dryers and to incite public authorities and industrials to invest in this promising niche. This work aims to strengthen the contribution of renewable energies and particularly solar energy in the sustainable development of the agri-food sector. Indeed, using solar energy will reduce the energy consumption and decrease greenhouse gas emissions of drying process. The prefeasibility analysis is achieved using the RETScreen Suite. Our study aims to investigate energy consumption of an industrial solar dryer of tomatoes, located in the city of Biskra. Various parameters as solar collector type and drying air temperature were tested and discussed. The obtained results showed a reduction in energy consumption up to 35%. Likewise, the reduction of GHG emissions recorded very favorable rates. This study's findings provide a preliminary vision for investors in the agri-food sector to build their project so they may maximize their profit while supporting the environment by lowering carbon emissions.

PSIX-22 Maternal methane, carbon dioxide, and oxygen flux compared with progeny gas flux

Abstract Red Angus heifers [n = 19; body weight (BW) = 370 ± 8.1 kg) and their paired offspring (BW = 283 ± 4.2 kg; 18 heifers, 1 steer) were used to compare the respiration gas parameters between dams and their progeny over 2 calving cycles (8 pairs in the 1st cycle, 11 in the 2nd). The methane (CH4), carbon dioxide (CO2) emissions and oxygen (O2) consumption of the dams were measured at 14 mo of age over a 70-d period using an automated head-chamber system (AHCS) that measured the flux of these 3 gases. Dams grazed native mixed-grass prairie and were offered a daily supplement of alfalfa (Medicago sativa L.) pellets (1.0 kg) via the AHCS. Dams were artificially inseminated using sexed semen (female) from a single Black Angus sire. The gas fluxes of the progeny were measured, beginning at 11 mo of age, over a 70-d period. Like the dams, during their measurement period, the progeny grazed native mixed-grass prairie and were offered a daily supplement (1.0 kg) of alfalfa pellets via the AHCS. Pearson correlations were developed between the 70-d means of daily CH4 and CO2 emissions, O2 consumption, CH4:CO2 ratio, respiratory quotient (RQ), and heat of production estimates for the dams and their progeny by regressing maternal parameters on the parameters of the progeny, using beginning dam and progeny BW as covariates, and year as an indicator variable. A dam’s CH4 emission was very strongly correlated with that of their offspring (ρ = 0.86). The CO2 emission and O2 consumption of the dams were both also very strongly (ρ = 0.92 and ρ = 0.97, respectively) correlated, with that of their progeny. The heat production and CH4:CO2 ratio of the dams were very strongly (ρ = 0.96) and fairly (ρ = 0.50) correlated, respectively, with that of their progeny. Lastly, the RQ of the dam was also very strongly correlated (ρ = 0.87) with the RQ of the progeny. These results indicate that CH4 and CO2 emissions, O2 consumption, CH4:CO2 ratio, and heat of production of the dam are fairly to very strongly correlated to the gas flux parameters of their progeny. Hence, even with this small dataset, there is evidence that beef cattle traits related to greenhouse gas emissions are somewhat heritable and could potentially be selected in breeding animals to decrease greenhouse gas emission intensity.

Comprehensive evaluation of microstructure and mechanical performance of sustainable ambient-cured alkali-activated composites

Cement is one of the building materials that is most frequently utilized in the construction field. However, the cement industry contributes significantly to the production of greenhouse gases. Therefore, many works have focused on improving sustainable construction materials that could contribute to decreasing greenhouse gas emissions. This study aimed to design a sustainable geopolymer mortar (GPM) made of fly ash (FA) and ground-granulated blast furnace slag (GGBS), which would be suitable for repairing damaged concrete structures. The work focused on investigating the effect of GGBS percentage, alkaline activator ratio, and superplasticizer dosage on the compressive strength, setting time, and workability of an ambient-cured GPM. The results of this research indicated that the compressive strength of GPM improved with the increase in GGBS percentage until a certain limit. However, the workability and setting time deteriorated with the increase in GGBS percentage. Increasing the alkaline activator ratio contributed to improving the compressive strength, workability, and setting time of GPM up to specific levels, but then they started to reduce. Superplasticizer dosage contributed to enhancing the compressive strength, workability, and setting time of GPM. This study found that the optimum FA/GGBS-based GPM that may be used in repair applications contains 50% GGBS, 50% FA, and 5% superplasticizer. The silica sand/binder ratio and alkaline activator ratio were 2.75 and 1.0, respectively. The compressive strength at 1 day, setting time, and workability of the optimum mix were about 12.70 MPa, 20 min, and 138.75 mm, respectively. The XRF, XRD, TGA, and SEM analyses were useful tools used to interpret the effects of the alkaline activator ratio on the fresh and mechanical properties of GPM.

Developing sustainable dairy farms in the tropics: From policy to practice

CONTEXTSustainable dairy production is included in the policy agenda of many countries in the tropics to address, among others, their commitment to the Paris Agreement. To the best of our knowledge, however, a study to assess the impact of the proposed interventions for sustainable dairy production is still lacking for most of those countries. Using policy goals as entry points to develop scenarios can provide insight into the impact of policy interventions on dairy farming practices. OBJECTIVEThis study aimed to evaluate the implication of interventions towards sustainable dairy development identified by the governments of Indonesia and Costa Rica. METHODSInformation about current farming practices (i.e. the baseline) were collected on 32 smallholder dairy farms in Indonesia and 24 dairy farms in Costa Rica. Scenarios were designed based on policy goals for dairy development and climate change mitigation in each country. The scenarios for Indonesia encompassed relocation of the dairy sector to Sumatra to allow coupling of livestock to land combined with a restriction on manure production to ensure all manure to be applied to grow forage, and a restriction on the amount of purchased feeds, at two levels: maximally 100% and 50% of the baseline. The scenarios for Costa Rica included a silvopastoral system and a reduction in the amount of purchased feeds, at two levels: 50% and 80% lower than the baseline. We estimated greenhouse gas (GHG) emissions at chain level and carbon (C) stocks at farm level. RESULTS AND CONCLUSIONSThe scenarios for Indonesia increased herd size and milk output by 240–360%, and GHG emissions per farm by 269–455%, while decreased GHG emissions per kg milk by 1–10%, compared to the baseline. C stocks per farm were higher in the scenarios than in the baseline, but compared to natural vegetation much more C is lost under the scenarios because more land is being used. The scenarios for Costa Rica reduced herd size and milk output by 5–25% and GHG emissions per farm by 17–35%, while GHG emissions per kg milk decreased by 10%, compared to the baseline. C stocks per farm were comparable. SIGNIFICANCETo achieve the multiple policy goals for sustainable dairy development, the governments need to consider the trade-off between increasing milk production and reducing GHG emissions. In Indonesia, relocation of the dairy sector needs a strict policy to avoid the expansion of dairy farms into tropical forest land. Furthermore, the Costa Rican government needs to incentivise dairy farmers to implement a silvopastoral system to reduce GHG emissions and land use. This, however, will be at the expense of milk output.

Updating soil organic carbon for wheat production with high yield and grain protein

Soil organic carbon (SOC) is crucial for mitigating global warming and significantly impacts crop production. While the relationship between SOC and wheat yield is well-documented, its effect on wheat grain protein content, which is essential for food security and human health, remains unclear. This study gathered management data from wheat farmers and collected plant and soil samples in the Huang-Huai winter wheat region, China’s primary wheat-growing area, from 2015 to 2022. Boundary line analysis was used to quantify the responses of wheat yield and protein content to variations in SOC. Our findings reveal that increases in SOC significantly enhance wheat yield and protein content. The highest yields, reaching up to 10,848 kg ha–1, and a maximum protein content of 17.3 % were observed in soils with SOC ranging from 7.8–18.1 g kg–1, and high-yielding, high-protein wheat exhibited higher spike numbers and grain weights and more efficient nutrient accumulation from soil or fertilizer to shoots. Optimizing SOC levels to produce high-yielding, high-protein wheat could substantially reduce nitrogen (N), phosphorus (P), and potassium (K) fertilizer use by 9.42×104, 0.70×104, and 3.66×104 Mg per year, decrease greenhouse gas emissions by 3.36 Mt CO2 eq and generate an economic benefit of 2.77 billion USD. In conclusion, our study expands the understanding of SOC’s role in crop production beyond crop yield, providing valuable insights for producing high-yielding, high-protein wheat.

Recent advances in sustainable nanomaterials for energy conversion and environmental remediation via photocatalysis

Photocatalysis is of particular interest because it can be utilized for reducing air pollution and decreasing greenhouse gas emissions. This review examined the latest advances in layered photocatalytic nanomaterials and single-atom catalysts and discloses the synthesis, structural features, and ways to enhance their catalytic ability. In particular, we describe the peculiarities of catalysis mechanisms in CO2 conversion, pollutant and NOx removal, and nitrogen reduction. The current trends in this field and the potential areas for further research are also discussed in this review. It is important to emphasize that single-atom catalysts possess distinct advantages to substantially improve the efficiency of energy conversion processes. The materials related to the synthesizing and post-processing of layered semiconductor catalysts and single-atom catalysts can be useful for other researchers and stakeholders.

Pemanfaatan Limbah Ikan Menjadi Pakan Bernutrisi Tinggi Solusi Inovatif Dalam Sektor Perikanan Di Kabupaten Kepulauan Selayar

Fishery waste consists of liquid and solid waste, accounting for 30-40% of the total weight of fish, mollusks, and crustaceans. Unfortunately, fish waste has not been well-managed due to its low economic value. However, with the advancement of technology, the opportunity to process fish waste into high-value products is increasingly open. Modern technology enables fish waste to be converted into high-quality fish feed, reducing the cost of commercial feed. The utilization of fish waste not only generates positive economic impacts but also significant environmental benefits. Processing fish waste into feed can reduce the risk of environmental pollution, decrease greenhouse gas emissions, and reduce pressure on wild fish resources. The use of feed from fish waste helps to promote more sustainable and environmentally friendly aquaculture practices. Research results show that using fish waste as an alternative feed in shrimp farming provides dual benefits for the environment and economy. Therefore, standard quality regulations are needed to ensure effective and safe management of fish waste for the environment and human health.

Sustainable Engineered Designs and Manufacturing of Waste Derived Graphenes Reinforced Polypropylene Composite for Automotive Interior Parts.

The automotive sector is actively pursuing a lightweighting strategy as a means to urgently decrease greenhouse gas emissions, which are a significant driver of climate change. The development of lightweight composite structures has been identified as crucial for enhancing part performance while mitigating negative environmental impacts and adopting energy-efficient manufacturing methods. This comprehensive study aimed to decrease the main reinforcement content of talc in commercial compounds while integrating graphene derived from waste polypropylene (PP) grown on talc and graphene nanoplatelet obtained from waste tires by upcycling processes into the PP compound. The entire value chain of interior automotive part production, from compound development and scaling up with a high-shear mixer, to injection molding of the part and performance tests, was investigated with a focus on sustainability considerations. The successful integration of 4 wt % micron talc, together with 1 wt % graphene nanoparticles and 1 wt % hybrid additive into the blended HomoPP/CopoPP matrix resulted in a 10% weight reduction compared to the conventional part. Moreover, significant improvements in flexural and tensile strength were observed, with enhancements of 52 and 38%, respectively. The uniform dispersion of additives and improved interfacial adhesion between the PP matrix and additives facilitated efficient stress transfer, contributing to enhanced mechanical properties. Furthermore, a systematic life cycle assessment study demonstrated the positive impact of waste PP incorporation on CO2 reduction, achieving a remarkable 95% reduction compared to virgin PP. The developed compound also demonstrated favorable processability and flow properties, supporting its potential for mass production. Overall, this study presents a sustainable and effective approach for lightweight automotive interior part production using a synergistically designed PP compound meeting the requirements of the automotive industry.

Urban Air Mobility for Last-Mile Transportation: A Review

Urban air mobility (UAM) is a revolutionary approach to transportation in densely populated cities. UAM involves using small, highly automated aircraft to transport passengers and goods at lower altitudes within urban and suburban areas, aiming to transform how people and parcels move within these environments. On average, UAM can reduce travel times by 30% to 40% for point-to-point journeys, with even greater reductions of 40% to 50% in major cities in the United States and China, compared to land transport. UAM includes advanced airborne transportation options like electric vertical takeoff and landing (eVTOL) aircraft and unmanned aerial vehicles (UAVs or drones). These technologies offer the potential to ease traffic congestion, decrease greenhouse gas emissions, and substantially cut travel times in urban areas. Studying the applications of eVTOLs and UAVs in parcel delivery and passenger transportation poses intricate challenges when examined through the lens of operations research (OR). By OR approaches, we mean mathematical programming, models, and solution methods addressing eVTOL- and UAV-aided parcel/people transportation problems. Despite the academic and practical importance, there is no review paper on eVTOL- and UAV-based optimization problems in the UAM sector. The present paper, applying a systematic literature review, develops a classification scheme for these problems, dividing them into routing and scheduling of eVTOLs and UAVs, infrastructure planning, safety and security, and the trade-off between efficiency and sustainability. The OR methodologies and the characteristics of the solution methods proposed for each problem are discussed. Finally, the study gaps and future research directions are presented alongside the concluding remarks.