Low Carbon Content Research Articles

ESTUDO EMPÍRICO SOBRE MODELAGEM E OTIMIZAÇÃO DO PROCESSO DEFRESAMENTO DE AÇO DUPLEX: UMA REVISÃO SISTEMÁTICA DE LITERATURA

One of the main production processes used in the metalworking industry is end milling. Thistechnique is used in the manufacture of automotive parts, molds and work tools in general. Duplex steel is a metallic alloy basically composed of 20% to 30% chromium and 5 to 10% nickel, with very low carbon content (less than 0.03%) and with additions of nitrogen, molybdenum, tungsten and copper. Response Surface Methodology (RSM) is astatistical technique used for modeling and analyzing problems in which the response variable is influenced by several factors, the objective of which is to optimize this response. The objective is to present a literature review focused on work that was carried out by modeling and optimizing the steel end milling process using RSM, seeking to identify the evolution of the topic over the years and gaps for improvement. To achieve this objective, the Systematic Literature Review was applied, which is a transparent, scientific and replicable method for carrying outthe literature review.

Influence of interface agent and form on the bonding performance and impermeability of ordinary concrete repaired with alkali-activated slag cementitious material

Alkali-activated slag cementitious materials (AASCMs) exhibit fast hardening, early strength development, high strength, and low carbon content, making them suitable for repairing damaged concrete. However, the bonding performance of the repaired interface and the impermeability of the repaired specimens require further evaluation. Accordingly, this study performed splitting tensile, water penetration, chloride ion penetration, and microanalysis tests on ordinary concrete specimens repaired with AASCMs. The results demonstrated that epoxy resin and cement mortar improved the interfacial bonding strength, water permeability, and chloride ion permeability of the alkali-activated slag cementitious material-Portland cement (AASCM-PC) specimens. The rectangular mortise joint and S-shaped interface improved the interfacial bonding strength and water permeability of the AASCM-PC specimens but slightly reduced their chloride ion permeability. Compared with ordinary concrete, AASCM has fewer harmful voids and denser microstructure, improving the impermeability of the repaired specimens.

PENGARUH TITANIUM DALAM LAPISAN LAS TERHADAP STRUKTUR MAKRO-MIKRO, KEKERASAN, DAN LAJU KOROSI

Low carbon steel cannot be hardened because of its low carbon content. Therefore, a hardfacing process is carried out to increase hardness. Apart from increasing hardness, the benefits of hardfacing can increase wear and corrosion resistance. The hardfacing process using the shielded metal arc welding (SMAW) process generally uses commercial electrodes. Therefore, it is necessary to add other elements such as titanium (Ti) to the weld layer to further increase its hardness. This research aims to study the influences of Titanium (Ti) addition in welding layers that were welded using HV 600 to micro and macrostructure, hardness, and corrosion rate. The hardfacing was conducted using the SMAW process with the various addition of Ti (0.115, 0.223, and 0.334 g) and cooled at room temperature. Macrostructure and microstructure were investigated using digital cameras and an optical microscope. Hardness and corrosion rate were investigated using the Vickers hardness test and weigh loss method. Based on macrostructure investigation, there is a perfect fusion between base metal and weld metal. The microstructure formed is a austenite, martensite and carbide phase. The lowest corrosion rate of 17.54 mpy was seen in the Ti1 sample. The lowest Ti addition would resulting higher hardness at 761.06 VHN.

The Impact of Termite Activity on the Availability of Soil Micronutrients in Tropical Regions

This research aimed to assess the impact of termite actions on the presence of micronutrients in tropical soil. A total of five combined soil samples were gathered from various termite mounds at a depth of 0-20 cm within the premises of Kano University of Science and Technology. The samples were examined for micronutrient levels using Microplasma Atomic Emission Spectroscopy (MP-AES). The findings revealed that the pH of the mounds' soil varied from 6.63 to 8.51, averaging at 7.46, categorizing the soil as slightly acidic to moderately alkaline. The zinc levels ranged from 0.68 mg/kg to 5.38 mg/kg, with an average of 2.52 mg/kg, indicating a high zinc concentration in the soil. Iron content showed a range of 43.72 mg/kg to 121.87 mg/kg, averaging at 78.05 mg/kg, placing it in the "high" range. Manganese levels varied from 7.70 mg/kg to 88.89 mg/kg, with an average of 37.22 mg/kg, also highlighting a substantial amount. Copper concentrations in the mounds ranged from 5.52 mg/kg to 53.33 mg/kg, with an average of 29.86 mg/kg. These outcomes illustrate that termite operations impact the presence of micronutrients, notwithstanding the low organic carbon content and cation exchange capacity of the soils. As a result, it is suggested that combining termite mound soil with organic manure or fertilizers could enhance soil productivity.

Nitrogen addition has divergent effects on phosphorus fractions in four types of soils

BackgroundGlobally increasing atmospheric nitrogen (N) deposition has altered soil phosphorus (P) transformations and availability, and thereby influenced structure and function of terrestrial ecosystems. Edaphic characteristics and chemical form of deposited N could be important factors determining impacts of N deposition on soil P transformations, yet the underlying mechanisms remain largely unknown. Objectives of this study were to examine how mineral-N and amino N differently affect P fractions, and identify key soil properties determining N addition impacts on soil P transformations. Considering that amino N is an important component of deposited N and forest soils vary greatly in different regions, the results of present study can guide the management of forests across different soils under ongoing N deposition scenarios.MethodsWe conducted a 60-day laboratory experiment to investigate the effects of N addition (NH4NO3 and glycine) on soil P fractions and related biochemical properties in four representative forest soils (brown, yellow brown, aeolian sandy, and red soils) in China. Glycine and NH4NO3 were separately added at three rates (5, 10 and 20 g N m–2 yr–1).ResultsFirstly, the percent changes in organic P fractions with N addition were significantly greater than changes in inorganic P fractions across all soils. Secondly, the percent changes in P fractions with glycine and NH4NO3 additions were significantly correlated across all soils and treatments. However, glycine addition had significantly greater impacts on organic P fractions than NH4NO3 addition in the aeolian sandy and red soils with low organic carbon content. Thirdly, P fractions responded differently to N addition among the four soils. N-induced changes in microbial biomass and phosphatase activities, pH, exchangeable Ca2+ and Mg2+ contributed differently to the changes in P fractions with N addition in the four soils.ConclusionsThe different responses of P fractions to N addition in the four soils were mainly generated by the differences in extent of microbial N limitation, acid buffering capacity, and cation exchange capacity among the soils. The different impacts of mineral and amino N on soil P fractions can be ascribed to their divergent effects on soil pH, microbial biomass and activities.

Can site-specific nutrient management improve the productivity and resource use efficiency of climate-resilient finger millet in calcareous soils in India?

Finger millet, an important ‘Nutri-Cereal’ and climate-resilient crop, is cultivated as a marginal crop in calcareous soils. Calcareous soils have low organic carbon content, high pH levels, and poor structure. Such a situation leads to poor productivity of the crop. Site-specific nutrient management (SSNM), which focuses on supplying optimum nutrients when a crop is needed, can ensure optimum production and improve the nutrient and energy use efficiency of crops. Moreover, developing an appropriate SSNM technique for this crop could offer new insights into nutrient management practices, particularly for calcareous soils. A field experiment was conducted during the rainy seasons of 2020 and 2021 in calcareous soil at Dr. Rajendra Prasad Central Agricultural University, Pusa, India. The experiment consisted of 8 treatments, viz. control, nitrogen (N)/phosphorus (P)/potassium (K)-omission, 75 %, 100 %, and 125 % recommended fertilizer dose (RFD), and 100 % recommended P and K + 30 kg ha−1 N as basal + rest N as per GreenSeeker readings. From this study, it was observed that the GreenSeeker-based SSNM resulted in the maximum grain yield (2873 kg ha−1), net output energy (96.3 GJ ha−1), and agronomic efficiency of N (30.6 kg kg−1), P (68.9 kg kg−1), and K (68.9 kg kg−1). The application of 125 % RFD resulted in ∼7 % lower yield than that under GreenSeeker-based nutrient management. Approximately 12 % greater energy use efficiency and 21–36 % greater nutrient use efficiency were recorded under GreenSeeker-based nutrient management than under 125 % RDF. The indigenous supplies of N, P, and K were found to be 14.31, 3.00, and 18.51 kg ha−1, respectively. Thus, 100 % of the recommended P and K + 30 kg ha−1 N as basal + rest N according to GreenSeeker readings can improve the yield, nutrient use efficiency, and energy balance of finger millet in calcareous soils.

Cyanobacteria-ferrihydrite aggregates, BIF sedimentation and implications for Archaean- Palaeoproterozoic seawater geochemistry

Abstract Precambrian banded iron formations (BIFs) are iron- and silica-rich (bio)chemical sediments that are widely believed to have been precipitated by microbial oxidation of dissolved Fe(II). The by-product of these metabolisms – insoluble ferric iron – would have settled through the water column, often as aggregates with the cell biomass. While the mineralogy, composition and physical properties of cell-iron mineral aggregates formed by anaerobic Fe(II)-oxidising photoferrotrophic bacteria have been extensively studied, there are limited studies that characterise cyanobacteria-iron mineral aggregates that formed during oxygenic photosynthesis. This gap in knowledge is important because it impacts sedimentation velocities and the Fe(III) to organic carbon (Corg) ratios in the marine sediment pile. Here, we used a recently introduced approach to precisely measure the sedimentation velocity of cyanobacteria-ferrihydrite aggregates and the Fe(III):Corg ratios of the cyanobacteria-ferrihydrite aggregates over a wide range of pH and initial Fe(II) concentrations under predicted Palaeoproterozoic atmospheric conditions. Our results indicate that it was highly unlikely BIFs formed at pH <7 via chemical oxidation due to the insufficient sedimentation velocity, even at the maximum predicted Fe(II) concentration of 1800 μM with excess oxygen. Instead, large Banded Iron Formation (BIF) deposits, such as those associated with the ca. 2.47 Ga Kuruman Formation in South Africa, would only had been deposited at minimum Fe(II) concentrations of 500 μM at pH 7 or 250 μM at pH 8. The Fe:Corg ratios in cyanobacteria-ferrihydrite sediments formed during initially anoxic Fe(II) oxidation experiments represent the maximum values under each condition because we specifically extracted samples after all Fe(II) was oxidised. The Fe(III) to organic carbon ratio was consistently below 4, which is also the ratio required for dissimilatory Fe(III) reduction (DIR). This result indicates that biomass in this case was in excess, which contradicts the low organic carbon content seen in most BIFs. Thus, we suggest that biomass was either physically separated from ferrihydrite aggregates during sedimentation under the influence of ocean currents and waves, or it was degraded prior to DIR. The mineralogical and geochemical evidences of both oxide and carbonate facies from the Kuruman Iron Formation (IF) suggest that ferrihydrite was most likely the precursor along with a significant initial organic carbon input, supporting the proposed cyanobacterially-mediated BIF depositional model and experimental results.

Methods for Measuring the Impact of Sustainable Tourism Development on Climate and Environment

Climate and environmental change is a growing topic in the post-Covid-1, when tourism growth is recovering. Tourism is a significant polluter of the environment and a rapid response to climate change is needed. Methods for assessing the climate and environmental impact of sustainable tourism development help to measure and communicate the environmental impact of tourism activities, but they are difficult to select and often lack indicators. The aim of the study was to choose methods for assessing the climate and environmental impact of sustainable tourism development in the context of Latvia. The study was based on the analysis of scientific literature, the grouping of methods for assessing the climate and environmental impact of sustainable tourism development according to their functional characteristics i.e. "preventive", "protective", "estimating" and "carbon emission determining" methods. A multi-criteria decision-making method was used for the selection of evaluation methods - Analytical hierarchy process with empirical analysis (AHA) of the obtained weights. By summarising the environmental and climate indicators available for a specific region of Latvia regarding the impact of tourism and experts evaluating the obtained results, the most suitable method for evaluating the impact of tourism development on the climate and environment is the Tourism value chain for low carbon content and efficient use of resources. However, the authors' recommendation for researchers: 1) when evaluating the impact of tourism development on the climate and environment, the choice of method ought to be based on evaluation indicators available for a specific study; 2) in research combinations of sets of "evaluative" and "carbon emission determining” methods should be used.

Evidence of a Proximity Effect in a (AgI)x - C(1-x) Mixture Using a Simulation Model Based on Random Variable Theory.

Silver iodide is a prototype compound of superionic conductors that allows ions to flow through its structure. It exhibits a first-order phase transition at 420 K, characterized by an abrupt change in its ionic conductivity behavior, and above this temperature, its ionic conductivity increases by more than three orders of magnitude. Introducing small concentrations of carbon into the silver iodide structure produces a new material with a mixed conductivity (ionic and electronic) that increases with increasing temperature. In this work, we report the experimental results of the ionic conductivity as a function of the reciprocal temperature for the (AgI)x - C(1-x) mixture at low carbon concentrations (x = 0.99, 0.98, and 0.97). The ionic conductivity behavior as a function of reciprocal temperature was well fitted using a phenomenological model based on a random variable theory with a probability distribution function for the carriers. The experimental data show a proximity effect between the C and AgI phases. As a consequence of this proximity behavior, carbon concentration or temperature can control the conductivity of the (AgI)x - C(1-x) mixture.

Mixture composition design of magnesium oxychloride cement-stabilized crushed stone materials applied as a pavement base

Conventional binding materials, such as silicate cement and lime, present high energy consumption, pollution, and carbon emissions. Therefore, we utilize crushed stone as a stabilization material. Magnesium oxychloride cement (MOC) is modified and used as an inorganic admixture owing to its eco-friendly nature and low carbon content. We analysed the control indicators of an integrated design of MOC-stabilized crushed stone by conducting unconfined compressive strength and water-resistance tests. The optimum mixing composition of the MOC-stabilized crushed stone was determined through the response surface methodology. We determined the best approach and dosage for improving the water resistance of MOC-stabilized crushed stone by comparing the effects of four modification methods: fly ash, citric acid + silica fume, phosphoric acid + waterborne polyurethane, and dihydrogen phosphate potassium salt. We also perform a comparison with 5% ordinary silicate cement-stabilized crushed stone. The results indicate that the MOC-stabilized crushed stone exhibits a rapid increase in strength in the early stage, but this rate reduces after 28 days. The mixing design employs the 4-day unconfined compressive strength and 1-day water resistance coefficient as the technical indicators. The best mixing composition includes a 4.27% MOC dosage and a molar ratio of MgO/MgCl2 of 5.85. We use 1% citric acid + 10% silica fume in equal amounts to replace the MOC dopant method for composite modification of the MOC stabilized crushed stone. Consequently, the 1-day water resistance coefficient before water immersion is significantly increased from 0.78 to 0.91 and its 4-day unconfined compressive strength is only reduced by 0.10 MPa. This significantly improves the water resistance of the MOC-stabilized crushed stone and ensures that its strength remains unaffected, which is the optimal modification method. However, this method must ensure that a small amount of citric acid and silica fume are uniformly distributed in the MOC-stabilized crushed stone, which increases the construction difficulty of the road base.

Evaluating Land Suitability for Wheat Cultivation Criteria Analysis Fuzzy-AHP and Geospatial Techniques in Northern Basrah Governorate.

Land suitability assessment is essential for planned land management strategies aimed at preserving soil and increasing productivity while ensuring sustainable agricultural production. Land degradation resulting from poor land management and fallowing practices typically leads to low land productivity in Iraq. To maintain agricultural productivity in the targeted area, agricultural requirements must align with available resources through land suitability analysis. In the northern region of Basrah Governorate in Iraq, the study focused on integrating GIS-based land suitability analysis with the fuzzy-analytical hierarchy process (F-AHP) approach. The analysis revealed varying suitability categories throughout the study area, with the largest proportion of unsuitable areas found in category N2, covering 31,202.36 hectares (37.76%), and category N1, currently unsuitable, covering an area of 19,956.24 hectares (24.15%). On the other hand, the moderately suitable category (S3) covered 8,297.26 hectares (10.04%), while the moderately suitable category (S2) covered 23,177.79 hectares (28.05%) of the total study area. No highly suitable lands were identified. The key determining factors for the suitability of lands for wheat cultivation were high values of electrical conductivity, carbonate minerals, bulk density, and low organic carbon content. Most agricultural lands are being used in a manner that contradicts their suitable potentials in the study area. Therefore, the pattern of agricultural land use needs to be adjusted based on their current potentials to reduce soil degradation.

Impingement of NPK and Rhizobium on Physico-chemical Properties of Soil under Cluster Bean (Cyamopsis tetragonoloba L.)

The study pertaining to the present topic under field investigation entitled “effect of different levels of NPK and Rhizobium on Physico-chemical properties of soil, growth and yield attributes of cluster bean” beginning from kharif seasons of the years 2023 at Research Farm, Department of Soil Science and Agricultural Chemistry. The excavated soil sample from experimental site before conducting research operation, mentioned that, the land topography range was nearly levelled with 1-3% slope, soil is of sandy loam texture with neutral to alkaline in reaction (7.140), electrical conductivity was non-saline (0.346 dS m-1) in nature, low organic carbon content (0.38%), low to medium available N (261.39 kg ha-1), available P (14.60 kg ha- 1) and available K (193.99 kg ha-1). Among nine treatments, during field experimentation, the conjunctive use of NPK and different Rhizobium levels, together come with best results significantly. However, the physical and chemical soil parameters, cumulative mean value for Bulk density (1.42 Mg m-3 and 1.45 Mg m-3),Particle density (2.64 Mg m-3 and 2.66 Mg m-3) and Soil pH (7.140 and 7.370) was found optimum in T1 (Absolute control) at 0-15 cm depth and 15-30 cm depth, respectively. Percentage porespace (45.17% and 43.17%), Water holding capacity (42.32% and 39.70%), Electrical conductivity (0.323 dS m-1 and 0.300 dS m-1), Percentage organic carbon (0.49% and 0.46%), Available N (284.41 kg ha-1 and 281.48 kg ha- 1 ), Available P (22.54 kg ha-1 and 21.29 kg ha-1 ), Available K (210.52 kg ha-1 and 203.98 kg ha-1 ) were found optimum in T9 consisting of (@ 100% NPK + @ 100% Rhizobium) in comparison to other NPK and Rhizobium levels application.

PROPERTIES OF URBAN SOILS AFTER DECONTAMINATION MEASURES ON THE RADIOACTIVELY CONTAMINATED TERRITORY OF THE CITY OF ELEKTROSTAL

We studied morphological properties, pH, organic carbon content, and specific activity of 137Cs and natural radionuclides (40K, 226Ra, 232Th) in the upper horizons of soils in deactivated and slightly damaged areas of the city. The studies were carried out in the urban ecosystems of the city of Elektrostal (Moscow region) in 2019, i.e. 6 years after local precipitation of 137Cs due to a radiation incident. Morphological features of the upper horizons of urban soils were: brownish-gray color, light-loamy composition, small-lumpy and lumpy structure, inclusions of construction and household waste. In the upper horizons of urbiquasizems and urban soils, a low carbon content (less than 1%) with high coefficients of variation - were detected. In the studied urban soils, a wide range of water pH values was noted: from acidic (4,6-5,5) to highly alkaline (> 8,0) reaction. Correlation analysis showed that in the upper horizons of UR, the content of organic carbon was reduced and alkalinization of the soil environment was observed. The accumulative type of distribution of 137Cs was recorded for soil profiles of polluted urban ecosystems in which decontamination measures were not carried out. The profiles of urban soils that were subjected to decontamination revealed low values of the specific activity of 137Cs in surface bulk layers and maxima in buried contaminated horizons. In the bulk horizons of UR, which include a large amount of crushed stone, there is an increase in the specific activity of 226Ra. Some technogenic horizons UR and TCH, consisting mainly of quartz sand, are characterized by very low values of specific activities 226Ra and 40K. Correlations of chemical and radiation indicators in the profiles of urban soils reflect the different composition and properties of upper horizons formed as a result of excavation and decontamination work.

Interaction of extreme drought and insect herbivores on grassland community is affected by drought pattern

Abstract Extreme drought and insect herbivores can affect plant community non-independently, and their interaction may be influenced by drought pattern. However, few studies have explored the interaction on plant community structure, and no study has investigated whether the interaction is affected by drought pattern. We explored the interaction of different extreme drought patterns and insect herbivores with a manipulated experiment in a semiarid grassland. There were three treatments for drought: control—ambient precipitation; chronic drought—66% precipitation reduction in the growing season (May–August); intense drought—completely exclusion of rain events from June to July. Herbivores removal and present treatments were imposed within each drought treatment. We found that although herbivores had no significant effects on the impacts of droughts on total species richness, it alleviated the impacts of chronic drought on total cover, and the alleviating role decreased under intense drought. Comparing with intense drought, more increasing of grass cover led to more alleviation under chronic drought associated with the decrease of forb which has low leaf carbon and dry matter content, along with high starch, calcium, magnesium and manganese concentration. These results indicate that the interaction of drought and herbivores is affected by drought pattern, and the changes in leaf traits that reduce herbivores feeding in grass might alleviate the impact of drought on grassland.

Dynamic breakthrough performance of low concentration CO2 adsorption in fixed-bed column with porous amino acid ionic liquid composites

Low concentration carbon dioxide (CO2) capture from air or confined spaces currently faces significant challenges, such as relatively poor dynamic adsorption breakthrough performance and cyclic stability. In our previous work, functionalized ionic liquid (IL) tetraethylammonium glycine ([N2222][Gly]) and porous molecular sieve (SBA-15) were combined to synthesize porous amino acid IL composite 60 wt% [N2222][Gly]@SBA-15 with microporous and ultra-microporous structures, which provide a new pathway for low concentration CO2 capture. In order to further obtain the dynamic CO2 adsorption breakthrough performance of this material under simulated actual working conditions, the effects of temperatures, relative humidity (RH) and CO2 concentrations on CO2 adsorption and desorption breakthrough performance of 60 wt% [N2222][Gly]@SBA-15 in a fixed-bed column were systematically studied in this work. The results indicated that CO2 adsorption capacity is up to 1.81 mmolCO2/g-adsorbent at 298.15 K, 1 bar and 0 % RH under 1 vol% CO2-containing gas mixture balanced with N2 and reaches 2.44 mmolCO2/g-adsorbent at 15 % RH due to the mechanism change of CO2 reaction with primary amine from 2: 1 under dry gas to 1: 1 stoichiometry in the presence of moisture. Moreover, the adsorbent maintains good cyclic adsorption-desorption performance. Further, CO2 adsorption breakthrough behaviors were well fitted by Avrami kinetic model, and the CO2 adsorption rate of 60 wt% [N2222][Gly]@SBA-15 was controlled by intra-particle diffusion. This work implied that IL-modified adsorbents have great potentials for low concentration CO2 capture applications.

Effects of operating parameters on start performance of compression ignition engine by using high-pressure direct-injection pure methanol fuel

Methanol was one of the research hotspots in internal combustion engines over recent years. The application of methanol is a promising approach to transport decarbonization due to low carbon content. However, the utilization of methanol in compression ignition (CI) engines faces some challenges as a result of low reactivity and high latent heat of vaporization, such as cold start and operation stability. Furthermore, the impact mechanisms of operating parameters on cold start and operation stability in CI engine have not been understood deeply. In this work, the effects of operating parameters on average cycle of start and coefficient of speed variation (CoVspeed) of idle were studied on a CI engine fueled by pure methanol fuel. Results show that the injection strategy of the minimum average starting cycle number is the pre-main injection, which includes lower injection pressure, −4 °CA ATDC (degree crank angle after top dead center) main timing, smaller pre mass, and larger pre-main interval. The injection strategy of the minimum CoVspeed of idle is the pilot-pre-main injection, which includes lower injection pressure, −4 °CA ATDC main timing, smaller pre mass, larger pre-main interval, smaller pilot mass, and shorter pilot-main interval. Under the same operating conditions, the average cycle of start is 12 and 5 for methanol and diesel respectively. The CoVspeed of idle is 6.72% and 0.53% for methanol and diesel respectively. When coolant temperature is 30 °C, the minimum intake temperature is 120 °C. Upon adjusting the coolant temperature to 80 °C, the minimum intake temperature decreases to 80 °C.

A Comprehensive Study on Net Zero Energy Buildings and Sustainable Construction Materials with Low Carbon Contents

One-third of the world's greenhouse gas emissions come from the building industry, with embodied carbon from the manufacture of building materials accounting for a sizable portion of these emissions. Prior research has mostly focused on examining the carbon emissions of low-rise structures, but it has failed to consider the significant influence that high-rise buildings have on a city's overall carbon emissions. Net-zero energy buildings (NZEBs) combine intelligent energy management strategies with conventional design knowledge to facilitate a sustainable and eco-friendly transition. The NZEB building revolution has the potential to become a long-term structural pillar for structures to come. The purpose of this study is to assess how various design factors and the embodied carbon in high-rise structures relate to one another. Additionally, the goal of this research is to keep annual consumer energy comfort in a home NZEB at its highest level without using any electricity from the electrical grid. In order to achieve long-term climate goals, our work emphasises the socio-economic advantages of adopting NZE buildings and further empowers consumer participation to minimise energy waste and carbon emissions. The findings provide a foundation for constructing high-rise structures in a more ecologically conscious manner to lower the structure's carbon emissions. The evaluation and comparison of the embedded carbon values takes into account the carbon emissions from the transportation and material manufacturing processes.

Combustion characteristics of Al/PTFE materials with different microstructures

The microstructures play a crucial role in the combustion of aluminum/polytetrafluoroethylene (Al/PTFE) materials. Mechanically activated Al/PTFE typically demonstrates higher reactivity but a lower combustion rate compared to physically mixed Al/PTFE. Recently, the combustion performance of fuel-rich Al/PTFE has been well explained by the microexplosion mechanism. In this study, the combustion characteristics of stoichiometric Al/PTFE (26.5:73.5 wt%) materials with varying microstructures were investigated to further the understanding of their combustion mechanism and offer insights for their potential applications in metal cutting. The Al/PTFE materials with different microstructures were prepared using sonication and ball milling methods. The results of scanning electron microscope (SEM) analysis suggest that the sonicated Al/PTFE (s-Al/PTFE) containing spherical Al particles displayed a loosely dispersed structure, while the milled Al/PTFE (m-Al/PTFE) exhibited a densely layered structure with flake-like Al particles coated by the PTFE matrix. The milled Al/PTFE was found to be mechanically activated. Combustion in quartz tubes was recorded using a high-speed camera and a video. Combustion of s-Al/PTFE demonstrated a high-temperature flame (∼2346 K) and obvious microexplosions featuring hot particles ejection, while combustion of m-Al/PTFE showed a weak flame (∼2037 K) and slow-burning, featuring dense carbon smoke. Increasing the powder density was observed to slightly decrease (∼100 K) flame temperature. Microstructure and phase analysis of combustion products were systematically conducted to elucidate the combustion behaviors. The results suggest that the residue of s-Al/PTFE contained high AlF3 and low carbon content, whereas the residue of m-Al/PTFE exhibited the opposite condition. The results of the combustion tests suggest that microexplosions promoted the oxidation of hot Al particles and carbon products, consequently leading to a fast reaction, high flame temperature, and enhanced heat transfer capability.

Quantification and isotopic characterization of benzene polycarboxylic acids (BPCA)-derived black carbon in deep oceanic sediments: Towards assessing pyrogenic inputs from marine sources

Methodologies based on benzene polycarboxylic acids (BPCA) selectively target the polymeric aromatic fraction of black carbon (BC) and are considered adequate to quantify pyrogenic inputs in environmental samples such as soils, lakes, and marine dissolved organic carbon. However, the usefulness of these methodologies to quantify BPCA-derived BC in deep-sea sediments has not been fully evaluated. In this manuscript we describe and validate a procedure to quantify BPCAs in deep oceanic sediments with very low organic carbon content. The resulting analytical procedure has produced reproducible quantitative data for BPCAs over a period of 10 months (coefficient of variation, CV = 6.4 − 6.6%). The stable carbon isotopes (δ13C) of BC_BPCA have been characterized using an LC Isolink™-irMS system with an accuracy better than 0.5‰. The quantitative and isotopic composition of several marine sediments has been characterized to investigate the relative contributions of marine/diagenetic and continental/pyrogenic sources to the BC accumulated in oceanic sediments from different contexts, ranging from upwelling systems to remote oceanic locations. Overall, a significant fraction of the sedimentary BC is of marine origin and should be considered in inventories of pyrogenic materials accumulated in the world oceans. However, the continental/pyrogenic sources can be largely dominant in marine settings with large inputs of pyrogenic materials.

Inclusion of Pseudomonas fluorescens into soil-like fraction from municipal solid waste management park to enhance plastic biodegradation.

Single-use facial masks which are predominantly made out of polypropylene is being used and littered in large quantities during post COVID-19 situation. Extensive researches on bioremediation of plastic pollution on soil led to the identification of numerous plastic degrading microorganisms. These organisms assimilate plastic polymers as their carbon source for synthesizing energy. Pseudomonas fluorescens (PF) is one among such microorganism which is being identified to biodegrade plastic polymers in controlled environment. The natural biodegradation of facial mask in soil-like fraction collected from municipal waste management site, bioaugmentation of the degradation process with Pseudomonas fluorescens, biostimulation of the soil with carbonless nutritional supplements and combined bioaugmentation with biostimulation process were studied in the present work. The study has been conducted both in controlled and in natural condition for a period of 12months. The efficiency of the degradation was verified through FTIR analyses using carbonyl index, bond energy change, Loss in ignition (LOI) measurement along with CHNS analyses of residual substances. The analysis of results reported that carbonyl index (in terms of transmittance) was reduced to 46% of the control batch through the inclusion of PF in natural condition. The bioaugmented batch maintained in natural condition showed 33% reduction of LOI with respect to the control batch. The unburnt carbon content of the residual matter obtained from the furnace were analysed using CHNS analyser and indicated the lowest carbon content in the same bioaugmented batch. In this study, an attempt is made to verify the feasibility of enhancing biodegradation of single-use facial mask by bioaugmentation of soil-like fraction available in solid waste management park with Pseudomonas fluorescens under natural condition. CHNS and FTIR analysis assures the biodegradation of plastic waste in the soil-like fraction using Pseudomonas fluorescens under both controlled and natural environmental condition.