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Energy, Ecology and Environment
Number of Followers: 1  Hybrid journal (It can contain Open Access articles)ISSN (Print) 2363-7692 - ISSN (Online) 2363-8338 Published by Springer-Verlag  [2468 journals]
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- A procedure to implement kinetic modelling of wastewater treatment by
microalgae considering multiple contaminant removal-
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Abstract: Abstract Most of kinetic models applied to microalgal wastewater treatment are focused on the specific contaminant removal (i.e. correlating a limiting substrate to microbial growth) or considering autotrophic characteristic that cannot be correlated to the mixotrophic/heterotrophic cultivation of these microorganisms, specially treating wastewater. However, to find an integrated kinetic approach using the simultaneous removal of organic carbon, nitrogen and phosphorus (main macronutrients) is difficult considering the different characteristics of the wastewaters, and the high number of kinetic constants associated with complex models. In this sense, this study designed a procedure to apply the kinetic modelling of microalgal growth using both the Monod model and the Silva and Cerqueira model (multiple substrates), estimating the characteristic kinetic constants and simulating the bioprocess by implementation on Python language and using Particle Swarm Optimisation (PSO). For contaminants removal, the n-th order equation proved to be more suitable, with an intermediate order between 1st and 2nd order (i.e. 1 < n < 2) and with a kinetic constant 0 < k < 0.2, obtaining an error between 15 and 28%. Using the Monod model, the algorithm was able to determine μmax and Ks, which were shown in the intervals: 0 < μmax < 4 day−1 and 0 < Ks < 50 mg L−1 with error of 15–25%. In the Silva and Cerqueira model, analysing the delimitation of m and p resulted in the following interval of convergence between 0 < p < 0.5 and 0 < m < 2, obtaining an error between 4 and 17% was obtained (significantly lower than for Monod) and using multiple substrates. The algorithm of the procedure is presented.
PubDate: 2023-12-01
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- Non-destructive prediction of strength of geopolymer concrete employing
lightweight recycled aggregates and copper slag-
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Abstract: Abstract This study examined the effect of various design parameters on the relationship between compressive strength and ultrasonic pulse velocity (UPV) of geopolymer concrete. To prepare the data set, a series of samples were made with increasing alkaline activator liquid to binder (AAL/B) ratios and varying densities. The variation in density was attained by partial replacement of normal weight fine and coarse aggregates by denser copper slag and lightweight recycled aggregates, respectively. The influence of AAL/B ratio and density on compressive strength and UPV was evaluated. After comprehensive analysis of results, a unified empirical equation is proposed to non-destructively compute the compressive strength of geopolymer concrete using UPV, AAL/B ratio and density. The findings demonstrated that the suggested equation could accurately predict the compressive strengths with a high determination coefficient (Dc) of 0.97. In addition, an attempt was made to check the validity of the constructed equation by comparing it with other relevant published experimental data.
PubDate: 2023-12-01
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- Fast-kinetics adsorption of a binary solution containing cationic and
ionic pollutants using high-surface area activated carbon derived from
macadamia nutshell-
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Abstract: Wastewater is characterized by multipollutant, and the presence of competitive adsorption could affect removal efficiency. Hence, the decontamination of water by adsorption in a multicomponent system allows an understanding of the practically and adsorbent efficiency. In this study, we present an analysis of the adsorption phenomena in a binary solution comprising compounds from distinct families, a dye, and an antibiotic, utilizing activated carbon obtained through a sustainable procedure. Locally available agricultural biowaste, specifically macadamia nutshell (MNS), served as a sustainable precursor to produce hierarchical porous activated carbon. The activation conditions were fine-tuned using the Box–Behnken experimental design. The resultant activated carbon was employed to remove a binary solution (BS) comprising the cationic dye, methylene blue (MB) and an ionic molecule amoxicillin (AMX) under specified conditions, including a pH range of 2 to 12, an initial concentration of BS ranging from 50 to 800 mg/L, and an adsorbent dosage within the range of 0.1 g to 0.3 g in a single adsorption system. The results revealed that higher temperatures adversely impacted the carbon yield, with a pronounced interaction effect observed between temperature and time. The activation temperature and K2CO3:precursor molar ratio predominantly influenced the textural and morphological properties of the activated carbon. Under optimal conditions (900 °C, 1 h, and a K2CO3:precursor ratio of 2:1), remarkably high-surface area (1225 m2/g), pore volume (0.801 cm3/g), and a nanopore size of 0.406 nm were achieved. In binary adsorption studies, R2-MNS demonstrated a maximum adsorption capacity of 578.925 mg/g. A pH above 4.5 produced an antagonistic effect on the removal of AMX due to competitive adsorption. Evaluation of three isotherm models demonstrated that the Khan isotherm best describes the affinity of BS to R2-MNS. The pseudo-second-order kinetic model best describes the data, indicating a chemisorption mechanism. The interparticle diffusion test revealed that the adsorbent exhibited very fast adsorption behaviour at the initial stage. Graphical abstract
PubDate: 2023-11-18
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- Development of low-carbon recycled aggregate concrete using carbonation
treatment and alccofine-
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Abstract: Abstract Since the construction industry is one of the major sectors responsible for the overexploitation of natural resources and the production of greenhouse gases, there is an urgent need to adopt a sustainable and environmental friendly approach to mitigate climate degradation. Research has explored the potential of recycled aggregate (RA) as a viable alternative to natural aggregate in concrete production. Currently, several treatment methods are being employed to enhance the efficient incorporation of RA into concrete, aiming to address this issue. However, the effective utilization of RA in place of NA remains uncommon. In this study, an effort has been made to develop a low-carbon recycled aggregate concrete by utilizing 100% carbonation treated recycled coarse concrete aggregate (CRCCA) in place of natural coarse aggregate (NCA) and alccofine as mineral admixture. A comprehensive analysis was performed, comparing the properties of CRCCA to those of untreated recycled coarse concrete aggregate. This analysis covered changes in weight, bulk density, water absorption, crushing value, and microstructure. Furthermore, five different concrete mixes were prepared, each varying in the proportion of natural coarse aggregate (NCA), untreated RCCA, and CRCCA. These mixes also incorporated alccofine as a mineral admixture. The evaluation process involved assessing the effectiveness of carbonation treatment and alccofine addition through tests on the workability, water absorption, density, and compressive strength of the concrete mixes. The study demonstrated that carbonation treatment of RCCA resulted in substantial improvements in crushing value and water absorption of CRCCA, alongside enhanced workability, reduced water absorption, and increased density in CRCCA concrete. Moreover, CRCCA concrete exhibited notable compressive strength gains at both 28 and 90 days compared to untreated RCCA concrete. Furthermore, the use of CRCCA and alccofine contributed to reducing GHG emissions associated with cement production, emphasizing the environmentally friendly attributes of this low-carbon concrete formulation.
PubDate: 2023-11-14
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- Influence of seasonal air density fluctuations on wind speed distribution
in complex terrains in the context of energy yield-
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Abstract: Abstract Given the variable nature of wind speed and the importance of accurately determining the energy that can be generated at a given site, understanding the wind speed at different time scales is crucial. In addition to differences within a very short period (i.e., hourly and daily), these changes are also pronounced throughout the seasons. They are affected by the atmospheric conditions and the terrain's complexity. Therefore, this study investigates the seasonal wind speed variability and its impact on the potential energy generation in a representative study case of Koznica, the mountainous region in Kosovo. The wind speed measurements campaign started in May 2019 and ended in April 2020; the measurements were made at a 10 min time scale. Ground measurements show that the wind direction is mainly northwest and southeast. Then, the wind speed and potential energy generation variability analysis were conducted for three different measurement heights. The results show that winter and spring have the highest potential wind energy capacity with an average speed of 6.7 m/s. In comparison, the average wind speed is 6.12 m/s. Potential energy generation for each season (i.e., spring, summer, autumn, and winter is as follows: 64,396.7, 22,040.3, 42,539.3, and 46,417.2 MWh/year, respectively, while the average capacity factor is 25%. Solution-oriented findings from this study might provide valuable insights to policymakers and investors regarding wind power energy exploration in Kosovo and other places with similar geo-climatic conditions.
PubDate: 2023-11-14
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- Global household energy consumption structure: direct versus embodied
perspective from 2000 to 2014-
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Abstract: Abstract Households play a crucial role in global energy consumption. Based on a dynamic multi-regional input–output model, this study examines household energy consumption patterns worldwide and their driving forces from 2000 to 2014. The results reveal the continuous increase in global household energy consumption over the study period: the total amount of household embodied energy consumption being roughly three times that of their direct energy consumption. Despite the shift toward cleaner household direct energy consumption in some countries, the structure of household embodied energy consumption has not changed significantly. The energy transition still requires more effort. The structural decomposition analysis shows that the demand-level effect contributes most to the growth of household embodied energy consumption, while the energy-intensity effect is the main factor offsetting the growth. The analysis at the regional and sectoral levels provides insights for promoting household energy conservation and transition, especially for embodied energy.
PubDate: 2023-11-09
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- (Re)-thinking the red seaweed biomass for biofuel production to meet
sustainable development goals toward circular bioeconomy-
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Abstract: Abstract The present energy demand and technological advancements in biofuel generation favor bioethanol, biobutanol, biodiesel, biogas, and biohydrogen production from renewable substrates. Bioethanol is one of the clean biofuels that has gained widespread acceptance as an alternative to fossil fuels and can be easily adapted in the automotive industry to design engines. Up to date, the commercial production of bioethanol obtained from first-generation biomass as substrates have led to a "Food vs. Fuel" issue. The ecosystem is affected by the use of hazardous pesticides and fertilizers in the cultivation of first-generation crops. These issues compel us to focus on a varied group of autotrophic organisms, the seaweeds, in this article as a potential replacement substrate for bioethanol production. Recently, the spent biomass of the seaweed industry and the economically viable seaweeds that drift on shore have been widely focused on generating revenue by many entrepreneurs and also helping farmers generate additional income from seaweed collection and processing. Classification and status of seaweed research were initially discussed in this article, and characteristics, pretreatment, bioethanol production of seaweed biomass, and spent seaweed biomass were articulated extensively. Eventually, a bioethanol economic scenario was developed to decipher the commercial feasibility of bioethanol in India.
PubDate: 2023-11-08
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- Durability studies on conventional concrete and slag-based geopolymer
concrete in aggressive sulphate environment-
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Abstract: Abstract As a potential substitute to conventional concrete, slag-based geopolymer concrete can be a promising material towards green and low carbon building approach. However, the lack of understanding of its performance subjected to sulphate environment can prohibit its use to some extent. This study examines the properties of conventional concrete exposed to a severe sulphate environment in comparison with slag-based geopolymer (SGPC). Plain cement concrete (PCC) also known as conventional concrete was cast using ordinary Portland Cement (OPC) as a binder. The durability of both types of concrete was examined by immersing test specimens in sulphate solutions (for varied salt concentrations of 2 and 4 g/l) for different curing ages up to a year. The performance of both types of concrete was studied for both mechanical and durability properties. Mechanical properties included compressive, tensile and flexural strengths (FS), while durability consisted of sorptivity, chloride diffusion, corrosion, EDS and SEM studies. The outcomes of this study revealed that the compressive (CS) and split tensile strengths (STS) of both OPC and SGPC decreased with the increase in magnesium sulphate salt concentrations and curing age. After being exposed to a 4% sulphate solution for 365 days, a decrease in the compressive strength was observed by 36.53% in SGPC and 55.97% in OPC, and a similar trend was found for the FS and STS. Rapid chloride permeability (RCPT) and sorptivity test results showed an increased diffusion with age and thus supported the findings of the compressive strength. Micro-structural properties were also studied, and observations showed that the formation of Sodium alumino-silicate hydrate (N–A–S–H) and Calcium alumino-silicate hydrate (C–A–S–H) was more obvious with the curing age in SGPC. At the same time, C–S–H gel formation decreased in conventional concrete with an increase in sulphate salt concentration. The cumulative effect of all these factors led to a much higher corrosion rate of rebars embedded in conventional concrete than in SGPC. Therefore, slag-based geopolymer concrete performed better than conventional concrete in an aggressive sulphate environment for all curing periods.
PubDate: 2023-11-04
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- Mechanical and microstructural properties of fly ash-based engineered
geopolymer mortar incorporating waste marble powder-
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Abstract: Abstract The marble processing industry produces a large volume of unmanaged waste in the form of microfine marble particles, usually referred as waste marble powder (WMP). Unregulated and open disposal of WMP has adverse effects on the environment. Marble is usually rich in calcium content, which can be used in geopolymer technology, thereby enhancing its recycling value. This research sought to determine the viability of WMP as a supplementary binder and polymerisation potential of its high calcium content (55.96%). For this purpose, WMP was used as fly ash replacement by weight (0, 5, 10, 15 and 20%) in geopolymer mortar (GPM) while other mix proportions are kept the same. The results indicated that WMP substitution adversely affected the water absorption (WA), ultrasonic pulse velocity (UPV), compressive and flexural strengths of engineered GPM. The mechanical strength trends were supported by, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy tests, which revealed that the calcium content of WMP showed poor alkali activation. Marble particles remained unreacted in the GPM matrix and failed to form additional geopolymeric compounds as Ca/Si ratio was found to consistently decrease with higher WMP substitution. Accordingly, WMP can be used in geopolymers in combination with siliceous binder (fly ash) without significantly reducing the mortar mechanical properties and thus the resulting GPM can find broad applications in practice.
PubDate: 2023-11-04
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- Alternative construction materials from industrial side streams: Are they
safe'-
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Abstract: Abstract The global population is continually generating vast amounts of waste materials across various sectors, leading to environmental challenges associated with landfill disposal. This study aims to examine the leachate and the antimicrobial properties of several waste materials to explore their potential applicability in the construction industry. Here, ICP-OES analysis and Kirby Bauer test were conducted on ready-mix concrete plant (powder residues), precast industries, recycled alkali-activated materials, municipal solid waste incinerated (MSWI) bottom ash, MSWI fly ash, High alumina tailing, and High magnesia tailing, to explore their potential applicability in the construction industry. Aluminium, calcium, silicon, potassium, and magnesium were the major ions leached from the waste materials, with MSWI fly ash and bottom ash showing higher levels of heavy metal leaching. The levels of leached aluminium, barium, chromium, lead, and zinc from MSWI fly ash and bottom ash were quantified, with values reaching up to 28.7 ppm, 4 ppm, 3.9 ppm, 11 ppm, and 25 ppm, respectively. Additionally, all samples demonstrated some level of antimicrobial activity against Escherichia coli and Staphylococcus aureus, which could be related to their alkaline pH and the release of certain ions. Improper disposal of waste materials in an open environment can potentially lead to contamination by heavy metals and harmful bacteria, which can pose a significant health risk during handling. This study results provided valuable information regarding the safety of using these wastes in the construction industry.
PubDate: 2023-11-02
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- Climber ecology and CO2 mitigation potential in an urban landscape
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Abstract: Abstract Climber species tend to provide various important ecosystem services within the habitat condition. Very little study was conducted on climber diversity, biomass, carbon (C) stock, and CO2 mitigation under urban setup. To address this research gap, the present study was conducted to evaluate the phytosociological attributes, diversity, climbing mode, host specificity, and their potential role in combating climate change. The study was carried out across the four directions of Ambikapur in various seasons using a random sampling method. Results revealed 11 species of climbers representing 9 families across the various study sites in different seasons. Most of the climber species were found to be herbaceous vine and woody wine in nature followed by the higher representation of stem twiner as climbing mode. Variation in species diversity across the study sites revealed higher value toward the west direction as reflected by the beta diversity value. Further, species richness and diversity were mostly reported from the east and north direction. The higher biomass, C stock, and mitigation value were recorded for the south direction in various seasons. Species such as Ampelocissus latifolia, Cuscuta reflexa, Cryptolepis buchanani, Ipomoea quamoclit, Mucuna pruriens, and Thladiantha cordifolia reflected higher biomass accumulation followed by C stock and greater CO2 mitigation potential among the observed climber species across various sites in various seasons. The present study highlights the importance of climber species under the urban ecosystem as a potential alternative for regulating the urban ambient environment followed by mitigation of changing climate.
PubDate: 2023-10-28
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- Improving agricultural practices: application of polymers in agriculture
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Abstract: Abstract Agricultural industry has been the root of all growth in India and all over the globe, with practices that can be dated back thousands of years, hence there is a need to improve technology and improvise advanced methodologies. Currently one of the major sections in the agricultural industry uses chemicals like fertilizers, pesticides, and insecticides, among other agrochemicals to enhance the productivity of crops. These chemicals pose a risk to human health and the environment, by causing land, water, and air pollution. There is an imminent need for better alternatives to these agrochemicals. This review summarizes one such alternative, the Agro-polymers, specifically designed and employed for enhanced crop productivity. Their versatile nature and various applications are based on features like protective and preventive properties of certain antimicrobial, antifungal, molluscicidal, and herbicidal polymers, water absorbance and retention capabilities of superabsorbent polymers and hydrogels, and controlled delivery of agrochemicals and nutrients property of polymeric delivery systems. The paper discusses future research prospects, with a focus on enhancing the efficiency, stability, and safety of agro-polymer applications. It emphasizes the need for continued research to optimize the use of polymeric materials in agriculture and ensure their compatibility with global environmental requirements.
PubDate: 2023-10-28
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- Donor-side valuation of forest ecosystem services in China during
1990–2020-
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Abstract: China’s forest ecosystem service supply has faced intense pressure during the last few decades, calling for a unified valuation on a long timescale to reveal its temporal and spatial changes. Yet, existing studies are confined to static valuations for a single year at the regional scale, while a temporal–spatial investigation for the ecosystem service value of China’s various forest types at the national scale is currently lacking. This study quantified the ecosystem service value of China’s various forest types during 1990–2020 and analyzed its temporal–spatial variations. As a supplement to emergy analysis, a unified assessment framework based on cosmic exergy as a biophysical metric has been proposed for ecosystem service valuation. Results showed that forests in southwest, southeast, and northeast China were the major providers of ecosystem services. From 1990 to 2020, although the aggregated value of China’s forest ecosystem service increased by only 4%, the service value of forests in coastal, northeast, and southwest China showed a declining trend. We also found that evergreen needleleaf forests, deciduous broadleaf forests, and evergreen broadleaf forests respectively contributed 35%, 29%, and 28% to the total service value, while in terms of ecosystem function types, erosion control, microclimate regulation, air purification, and soil purification contributed 27%, 22%, 22%, and 19% to the total, respectively. The outcome of this study may provide a new methodological framework and a benchmark reference for forest ecosystem service valuation, which is supportive of formulating forest management measures for different types of forest ecosystems. Graphical
PubDate: 2023-09-27
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- Green synthesized silver nanoparticles mediated regulation on hydrolytic
enzymes and ROS homeostasis promote growth of three pulses (Cicer
arietinum L., Pisum sativum L., and Vigna radiata L.)-
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Abstract: Pre-sowing seed treatment with nanoparticles has a promising role towards the improvement of seed germination and seedling growth. In the present study, silver nanoparticles (AgNPs) were synthesized from silver nitrate (AgNO3) through green route using aqueous extract of Parthenium hysterophorus L. roots. The synthesized nanoparticles were characterized using various analytical instruments such as UV–Vis spectrophotometer, TEM, SEM, EDX, XRD, and FTIR. Further, the impacts of AgNPs, AgNO3, and plant extract on germination, seedling growth, activity of hydrolytic enzymes, and ROS generation of three pulses (Cicer arietinum L., Pisum sativum L., and Vigna radiata L.) were investigated. Characterization of nanoparticles revealed that the green synthesized AgNPs were mostly spherical with an average size of 11–20 nm and crystallinity was 71.3%. The growth experiment revealed that seed germination and seedling growth were increased under AgNPs (10 and 50 mg/L) and AgNO3 (10 mg/L) treatments as compared to control for three tested pulses. Results also demonstrated the increased hydrolytic enzyme activities during early seedling establishment of three pulses under nanoparticle treatments. Meanwhile, dose dependent increase in ROS production was recorded under both AgNPs and AgNO3 treatments and it was always higher in AgNO3 as compared to AgNPs treatments. However, the growth inhibition at higher concentrations of both AgNPs and AgNO3 treatments suggested that the ROS generation at an optimum level might play an important role towards the enhancement of seed germination. Therefore, AgNPs mediated alteration of the activity of hydrolytic enzymes and generation of ROS might regulate early seedling establishment. Graphical abstract
PubDate: 2023-09-12
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- A leaf litter fermented product as a source of low-molecular-weight
compounds with potential to enhance cold tolerance of Begonia grandis-
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Abstract: Abstract A leaf litter fermented product (LLFP) was prepared via aerobic fermentation of leaf litter of Betula pendula by indigenous microflora. The LLFP exerted effects on the growth and cold tolerance of Begonia grandis plants cultivated outdoors under the conditions of the forest-steppe zone of West Siberia. Despite the sufficient data on the positive effects of similar products as biostimulants and boosters of stress tolerance, there is a gap in information about their active ingredients. The biggest gap is related to low-molecular-weight components. Chromatographic profiling of the LLFP in comparison with green leaves and leaf litter of B. pendula as performed by high-performance liquid chromatography revealed a significant decrease in the concentrations and number of phenolic compounds. The chromatographic profile of the LLFP showed salicin and oxalic, ascorbic and gallic acids as the main extracted organic compounds. Meanwhile, a substantial amount of indoleacetic acid (1.26–4.13 ng mL−1) and traces of abscisic acid and t-zeatin were revealed by liquid chromatography with tandem mass spectrometry. The LLFP showed dose-dependent free-radical–scavenging activity. The results indicate that phytohormones, most likely of microbial origin, are the main active ingredients of the LLFP. Phenolic compounds can enhance antioxidant properties of B. grandis plants and soil health; besides, organic acids improve assimilation of nutrients from soil. The results hold promise for a uniform approach to the assessment and prediction of the quality of plant fermented products for their wide dissemination as ecofriendly and sustainable products.
PubDate: 2023-09-01
DOI: 10.1007/s40974-023-00292-7
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- Effect of heating tube arrangement on nano-enhanced thermal energy storage
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Abstract: Abstract Improvement of thermal performance of energy storage leads to energy savings and reduction of carbon emissions. In this study, the effect of tube arrangement on the performance of thermal energy storage is examined during the melting process of a phase change material (RT50). The heat transfer and phase change modeling are based on conservation equations and lattice Boltzmann method. The combined effect of the tube's vertical position and nanoparticles are studied for various nanoparticle concentrations and Rayleigh numbers. Natural convection, melt fraction, heat storage, and storage time are examined and discussed. The results indicate that tubes placed at the horizontal centerline of the cavity is the best arrangement for reducing the charging time at low heating rates (Ra = 104), while downward displacement of one heating tube is more effective at high heating rates (Ra ≥ 105), the loading time can be reduced by up to 28%. The results of this study can guide design of efficient thermal energy storage systems.
PubDate: 2023-08-04
DOI: 10.1007/s40974-023-00291-8
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- Sustainable energy production from grape marc: from thermo-analytical and
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Abstract: Abstract Managing winery solid waste remains a challenge. The aim of this work is to experimentally study grape marc (GM) as a possible sustainable biofuel and/or as an auxiliary fuel with lignite. GM co-combustion with lignite has never been reported. Several thermo-analytical techniques (Calorific Value, Proximate Analysis, Ultimate Analysis, Thermogravimetry/Derivative Thermogravimetry, Ion Chromatography, Scanning Electron Microscope/Energy-Dispersive Spectroscopy) and several other analyses (Kinetic Modeling, Thermodynamic Analysis) were performed. The Environmental Footprint Index (produced ash per megajoule), the potential Maximum Emission Factors (per megajoule) and several Ash Quality Indices were calculated. The main results showed that GM is a very promising alternative to lignite fuel since its energy content is extremely high (~ 19.3 MJ/kg) while its ash content is quite low (~ 5.7 wt.%) compared to lignite. This means that more energy can be produced by simultaneously reducing solid waste (ash) production and problems related to ash. Similarly, the GM sample is superior to lignite regarding gas emissions for producing the same amount of energy (98.5 gCO2/MJ, 0.5 gNO/MJ, and 0.5 gSO2/MJ). Kinetic analysis showed that GM combustion is kinetically favored over lignite due to its lower Activation Energy (64.7 kJ/mol). Similarly, as the proportion of GM is increased in the blends, the quality characteristics of the composite fuel becomes better. The Empirical Chemical Formula of the GM is C277N10SH398O134. Cl− content was the same as for lignite (0.02 wt.%). Experimental and modeling results revealed that GM, and its co-combustion with lignite, in several proportions, could be used for bioenergy production.
PubDate: 2023-07-28
DOI: 10.1007/s40974-023-00288-3
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- Thermal analysis of a dynamic double-layer phase change material building
envelope-
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Abstract: Abstract Integration of phase change material (PCM) into the building envelope can improve building energy efficiency. This work aims to numerically investigate the performance of mobile PCM layers in a building wall during different seasons (summer and winter). Various combinations of PCM melting temperature are investigated. The modeling is based on conduction heat transfer and enthalpy method. The results highlight the best combination for temperature regulation in both summer and winter, resulting in the highest performance. Furthermore, combinations with melting temperature close to the outside fluctuating temperature and to the inside comfort temperature (according to the season) ensure the best annual performance of the building envelope in terms of smoothing the instantaneous heat flux and diminishing the fluctuating temperature amplitude. Moreover, the best option with PCM fraction of 35% decreases the required power for heating and air conditioning by up to 12%.
PubDate: 2023-07-16
DOI: 10.1007/s40974-023-00289-2
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- Vegetation response to a natural gas pipeline rupture fire in
Canada’s montane cordillera-
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Abstract: Abstract Pipelines are critical for energy distribution, but incidents causing rupture fires are hazardous. While wildland fires are a natural disturbance, rupture fires are a potential risk and novel disturbance given the greater heat yield constants for fossil fuels, fuel volume, and flaming concentration and duration. We quantified vegetation response to a 2018 rupture fire case study in the montane cordillera of Canada. Plant species, functional groups, ground cover, and live vegetation height were sampled in 2018, 2019, 2020, and 2021 [0, 1, 2, and 3 years since fire (YSF)] in permanent plots stratified by burn severity and compared to the unburned reference plots sampled in 2019. Woody plant species and forb cover in burned plots recovered to levels similar to unburned plots. Litter and bare soil changes relative to YSF suggest trajectories to return to levels similar to unburned plots within 3 to 5 years post-rupture. Plant species richness, evenness, and diversity had also recovered to levels statistically similar to unburned comparisons by the final year of sampling in this study. Plots closest to the rupture epicenter that experienced ‘extreme’ burn had greater botanical dissimilarity from other burn severities or unburned comparisons. Vegetation structure showed significant (p < 0.0001) recovery with additional growth expected as the overstory re-establishes. The multiple metrics of ecological recovery on 3–5 year trajectories are comparable to published responses to wildland fire in the literature for this ecosystem’s response to fire. The recovery of conifers and soil microbiota should be assessed in the next decade.
PubDate: 2023-07-08
DOI: 10.1007/s40974-023-00287-4
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- Laboratory performance of asphalt mixtures incorporating electric arc
furnace slag and basic oxygen furnace slag as partial replacement for
conventional aggregates-
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Abstract: Abstract The usage of unconventional aggregate materials in road construction is still in the experimental stage. A possible environmental risk is the continued use of conventional aggregates in the construction of roads and highways. The issue may be resolved by sensible mitigating measures and essential research on substitute aggregate materials. The present article investigates the laboratory performance of asphalt mixtures incorporating electric arc furnace slag (EAF) and basic oxygen furnace (BOF) slag as partial replacements (10%, 30%, and 50%) for conventional aggregates. Surface morphology and chemical composition of aggregates have been studied using SEM and EDAX analysis. The characteristics of the asphalt mixture’s mix design, including abrasion loss, moisture sensitivity, rutting resistance, fatigue behaviour, and resilient modulus, were investigated. Results indicate that the mix design properties of asphalt mixtures with EAF and BOF slag were within the requirements. Further, the incorporation of EAF and BOF slag in asphalt mixtures reduced abrasion loss irrespective of replacement percentage. Moisture sensitivity, rutting, fatigue, and resilient modulus properties of asphalt mixtures with 30% EAF slag were higher compared to asphalt mixtures with 30% BOF slag and conventional mixtures. However, asphalt mixtures with 50% replacement of EAF and BOF slag were lower compared to control mixtures. According to the findings, the optimum replacement percentage for EAF and BOF steel slag is 30% conventional aggregate. When compared to BOF steel slag, EAF steel slag performed better in terms of moisture sensitivity, rutting resistance, fatigue behaviour, and resilient modulus. The results of this study can be used as a reference for creating recycled asphalt mixtures with slag aggregates sourced from the steel industry.
PubDate: 2023-06-14
DOI: 10.1007/s40974-023-00285-6
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