Dry Carbon Research Articles

Dry carbon dioxide bath in medical rehabilitation of children with various diseases

The article presents the main aspects of using dry carbon dioxide baths in the medical rehabilitation of children with various diseases. The main aspects of the formation of the mechanism of the therapeutic effect in bronchial asthma, atopic dermatitis, dysautonomia, and other diseases are presented.The inclusion of dry carbon dioxide bath in the complex of rehabilitation measures in children with bronchial asthma helps to reduce the intensity of allergic inflammation and bronchial obstruction, as well as the frequency of exacerbations of the disease and the drug load. In patients with atopic dermatitis, there was a decrease in the main clinical symptoms of the disease and an improvement in the psycho-emotional state under the influence of dry carbon dioxide bath. With the dysautonomia syndrome, after a course of dry carbon dioxide baths, a favorable restructuring of autonomic regulation is observed, aimed at reducing tension in the sympathetic department of the autonomic nervous system. In children who often suffer from acute respiratory diseases, the course use of dry carbon dioxide baths contributes to the regression of clinical symptoms of acute respiratory infections, improves mucosal immunity, and reduces the frequency of recurrent infections throughout the year.

Self-Sustained Programmable Hygroelectronic Interfaces for Humidity-Regulated Hierarchical Information Encryption and Display.

The emerging moisture-driven energy generation (MEG) technology opens up new possibilities for humidity-responsive materials, devices, and interdisciplinary opportunities in fields like information security. However, such potential remains untapped. Here, an original MEG structure with a hygroionic energy-conversion route by selective coating of ionic hygroscopic hydrogels on a carbon black surface is reported. The hygroionic route features a process in which the scavenged energy is stored in the electrical double layers formed at the interfaces between the ionic hydrogel and the carbon nanoparticles. The resultant electrical field developed across the hydrogel-coated wet carbon and the rest of the dry carbon area is thus durably lasted. Based on this unique structure, hygroelectronic information interfaces (HEII) for humidity-regulated information encryption and displayare put forward by devising hydrogel patterns on a carbon platform. Further by tuning the hygroscopicity of the ionic hydrogels and incorporating encoding methods (e.g., Morse code), it is demonstrated that the HEII platform is programmable to carry different information in certain humidity ranges. Unlike those conventional anti-counterfeiting methods that optically reveal the hidden information once the required stimulus is provided, the new HEII serves as a hierarchical solution for high-security encryption and display.

Feedstock flexible numerical analysis of sewage sludge gasification

Sewage sludge properties vary with the origin and treatment method of the wastewater. When converting the sewage sludge thermally for material and energy recovery, these properties affect the composition of the products and the efficiency of the process. Rotary kiln gasifiers can handle these variations in the raw materials. For further development, process integration, optimization of the process, upscaling, and industrial application, it is helpful to understand and describe the impact of the sewage sludge properties on operating parameters and product quality. This work analyses the impact of sewage sludge properties numerically using detailed chemistry and the surrogate approach. Sewage sludge is described using woody biomass components, sugars, lipids, proteins, inorganic species, moisture, and ash. The stochastic reactor model (SRM) is used to model the gasification process. In contrast to ideal reactors, stochastic reactors allow for resolving inhomogeneity. Hence, the predicted gas composition results from local temperature and available oxygen. For the analysis, temperature, airflow rate, and fuel properties, i.e., the amount and composition of volatiles, including fuel-bonded nitrogen and sulfur, and the moisture level are varied. Their results are analysed regarding the produced gas composition, emission precursor formation, and cold gas efficiency of the process. The highest efficiencies are found for temperatures of 1223 K and rich conditions. High concentrations of methane and hydrogen accompany this maximum. However, the producer gas’s highest heating value is found at low temperatures thanks to the presence of small hydrocarbons. Furthermore, a high volatile amount and a dry feedstock favour methane and carbon monoxide formation. The hydrogen concentration is found to be sensitive to the moisture content and is the highest at 30%. The cold gas efficiency is predicted to depend strongly on the feedstock and varies for the same operating conditions up to 60%. With increasing fuel-bonded nitrogen and sulfur content, the concentrations of NO and SO2 formation and their precursors increase, respectively. The released ammonia leads to significantly reducing emitted NO through the ThermalDeNOx mechanism. Overall, the generated maps provide a detailed insight in species formation and allows for the prediction of process parameters sensitive to the sewage sludge properties.

Experimental study on combined valorization of bituminous coal derived fluidized bed fly ash and carbon dioxide from energy sector

Carbon dioxide mineralization using alkaline earth metals rich waste, offers the opportunity of a combined utilization of captured carbon dioxide and valorization of burdensome waste. Most of the studies reported refer to the utilization of steel slags or combustion products of coal and petcoke blends, lignite, municipal waste or air pollution control system residues from conventional boilers. Indirect wet and direct dry carbonation methods under elevated pressure and/or temperature are mostly considered. Within this paper, the results of the experimental study on a dry, direct carbonation method with the use of bituminous coal derived fluidized bed fly ash and performed under ambient conditions are presented. The porous structure parameters of the process product, missing from the existing literature, are analyzed. Therefore, the study differs from the existing literature in terms of the carbonation method used, alkaline earth metals source, scale of the experiment, process conditions employed and product parameters studied. The efficiency of carbon dioxide uptake of 0.008–0.054 kgCO2/kg was proven to be comparable with reported for more energy- and cost-intensive methods. The development of porous structure of the process product was also demonstrated with up to several fold increase in the specific surface area and the total pore volume.

Analysis of the Efficiency of Technologies for Extraction Carbon Dioxide from Combustion Products

The main purpose of the article is to compare and analyze existing technologies for extracting carbon dioxide from combustion products in relation to mini-CHP plants operating on local fuels. The article presents a brief overview of the main technical features of the implementation of carbon dioxide extraction technologies from gas mixtures. The specific features and limitations for each of the methods are shown. Mathematical modeling of technological processes of adsorption, physical and chemical absorption is carried out on the basis of Aspen Hysys and Aspen Adsorption software packages. When modeling absorption processes, the composition of combustion products characteristic of the actual operating conditions of an energy source on wood chips was considered, while for the adsorption process, the composition of combustion products was simulated by a binary mixture of carbon dioxide and nitrogen with a molar content of 11 and 89 %, respectively. The results of numerical research that were obtained have shown that the highest degree of carbon dioxide extraction from combustion products is 97 %, and it is achieved in the optimal mode of implementation of chemical absorption technology. With the same method, the highest degree of purity of the resulting carbon dioxide is observed, viz. 86 % taking into account water vapor and 99 % if it is dry. The least effective technology for extracting carbon dioxide was the method of physical absorption in a fixed bed, in which the degree of purity of the resulting dry carbon dioxide was 79 %. Therefore, for practical use in the deep utilization of combustion products of mini-CHP plants operating on local fuels, to obtain carbon dioxide with a low content of impurities, it is necessary to apply the method of chemical absorption. The use of physical absorption technology in a fixed bed can be used to reduce energy source emissions or in cases where the degree of purity of carbon dioxide does not matter.

Numerical Study of the Hygrothermal Effects on Low Velocity Impact Induced Indentation and Its Rebound in Composite Laminate

Impact indentation is believed to be an effective indication of low-velocity impact (LVI) damage for polymer matrix composites. However, it has been discovered that an indentation can partially rebound over time. Impact indentation and its rebound behavior over a period of time are significantly affected by hygrothermal conditions, especially moisture absorption. Therefore, a good understanding of the moisture-dependent impact indentation and its rebound behavior is helpful for impact damage assessment for composites. In this paper, moisture effects are considered for both the intra-laminar transverse property model and the interlaminar interface model in the simulation of impact indentation. Then, in these two models, viscosities are introduced to represent the indentation rebound over time. In order to validate the proposed models, LVI experiments with different impact energies were conducted on dry and hygrothermal conditioned carbon fiber/epoxy matrix composite laminates. For the specimens, the initial depths of impact dents and their rebounds over time were measured. The specimens of hygrothermal conditions were found with deeper dents compared with dry ones under the same impact energy; and their rebounds were also more significant. These phenomena were explained by the fact that moisture softens epoxy in composite and meanwhile elevates its viscosity. This indentation and its rebound phenomenon were simulated in ABAQUS by considering the moisture effects and viscoelasticity with user-defined material subroutines. These experiments were simulated using the proposed models, and the numerical predictions conformed well with the experimental observations.

Predictive Thermal Modeling and Characterization of Ultrasonic Consolidation Process for Thermoplastic Composites

Abstract Ultrasonic consolidation (USC) of thermoplastic composites is a highly attractive and promising method to manufacture high-performance composites. This work focuses on USC of dry carbon fiber (CF) fabrics with high-temperature polyphenylene sulfide (PPS) films. Experimental trials to assess feasibility of the process are time-consuming. Consequently, a predictive thermal model would facilitate process parameters selection to reduce expensive trial-and-error approaches. This paper presents a 2D finite element model of samples under consolidation, incorporating equations for viscoelastic heating, matrix phase change, and material properties. Theoretical temperature profiles for nodes of interest were compared to the corresponding experimental temperature curves for various control parameters (i.e., weld time and vertical displacement of sonotrode) and showed good agreement during heating phase. It was found that welding time values below 1750 ms were insufficient to reach melting temperature, whereas weld times above 3000 ms led to the lowest average void content (2.43 ± 0.81%). More specifically, the time the material spent above melting temperature, i.e., residence time, was established as a parameter that could estimate cases resulting in better consolidation and lower void content (time above 2600 ms for void content below 2.5%). X-ray diffraction (XRD) characterization revealed that the USC process led to mostly amorphous PPS, due to the high cooling rates (70 °C/s to 108 °C/s). Overall, the thermal model and micro-structural outcomes confirmed the feasibility of the USC process for layered composites made from dry fabric and high-temperature thermoplastic films.

Rapid preparation of nickel fluoride motif via solution-free plasma route for high-energy aqueous hybrid supercapacitor

New and more accurate nano-material fabrication technologies are necessary to tackle the limitations of a conventional solution-based synthesis procedure for an efficient, sustainable, and carbon-free energy future. We devised a rapid, room-temperature yet solution-free dry carbon tetrafluoride (CF4) plasma strategy to cultivate the self-assembled nickel fluoride (NiF) motif nanostructure for a high-energy hybrid supercapacitor (HSC). The high reactivity of the CF4 plasma permitted the low temperature and rapid foundation of the NiF motif directly on the 3D Ni foam. The developed NiF motif nanostructure on the Ni foam delivers high electrochemical activity in terms of the specific capacity (1.18 mAh/cm2 at 1 mA/cm2), cycling stability (89.58 % retentions over 10,000 cycles), and rate capability (84.22 % at 10 mA/cm2) in conventional aqueous electrolytes. The ordered growth of the NiF motif nanostructure linked with high fluorine concentration (51.33 at%) provides large electroactive accessible sites and high electronic conductivity for the facial and reversible charge transport process. To further explore the potential of the NiF motif nanostructure, an aqueous HSC cell was assembled by using the NiF motif and activated carbon (AC) as positive and negative electrodes, respectively. The constructed NiF//AC HSC brings an energy density of 0.96 mWh/cm2 at a specific power of 3.18 mW/cm2 with excellent cycling durability (87.98 % over 12,000 cycles) and rate capability (84.55 %). The superior electrochemical parameters of the NiF motif and developed HSC cell indicate that the described synthetic approach can be extended to prepare a wide range of electrode materials rapidly and solution-free dryly.

Assessment of Carbon Fiber Reinforced Plastic (CFRP) composites Using COPRAS Method

The influence of concrete strength and between concrete and CFRP composites considering the type of interaction, Exterior of reinforced concrete beams Optimum composition of CFRP composites for reinforcement and is to reach the number of layers. (i) machinability Chip removal mechanisms, cutting force, tool wear, Surface roughness, deformation and uncut of CFRP including properties of fibers; (ii) CFRP Cutting tool requirements for machining; and (iii) recent Industry solutions: cutting tools, coatings and Advanced edge geometry of technologies. CFRP composite, dry carbon fiber adhesive system. Tensile strength, tensile modulus, Air weight. From the result is based on is the result seen and got the Tensile modulus first grade, whereas the Density having the lowest rank. The value of the dataset for CFRP composites in COPRAS method shows that it results in tensile modulus and top ranking.

Reliability of using vegetation optical depth for estimating decadal and interannual carbon dynamics

Vegetation optical depth (VOD) from satellite passive microwave sensors has enabled monitoring of aboveground biomass carbon dynamics by building a relationship with static carbon maps over space and then applying this relationship to VOD time series. However, uncertainty in this relationship arises from changes in water stress, as VOD is mainly determined by vegetation water content, which varies at diurnal to interannual scales, and depends on changes in both biomass and relative moisture content. Here, we studied the reliability of using VOD from various microwave frequencies and temporal aggregation methods for estimating decadal biomass carbon dynamics at the global scale. We used the VOD diurnal variations to represent the magnitude of vegetation water content buffering caused by climatic variations for a constant amount of dry biomass carbon. This magnitude of VOD diurnal variations was then used to evaluate the likelihood of VOD decadal variations in reflecting decadal dry biomass carbon changes. We found that SMOS-IC L-VOD and LPDR X-VOD can be reliably used to estimate decadal carbon dynamics for 76.7% and 69.9% of the global vegetated land surface, respectively, yet cautious use is warranted for some areas such as the eastern Amazon rainforest. Moreover, the annual VOD aggregated from the 95% percentile of the nighttime VOD retrievals was proved to be the most suitable parameter for estimating decadal biomass carbon dynamics among the temporal aggregation methods. Finally, we validated the use of annual VOD for estimating interannual carbon dynamics by comparing VOD changes between adjacent years against eddy covariance estimations of gross primary production from flux sites over several land cover classes across the globe. Despite the large difference in spatial scales between them, the positive correlation obtained supports the capability of satellite VOD in quantifying interannual carbon dynamics.

Concurrent function of high-strength dry carbon fiber as resistive heating element and thermistor in ambient air

Measuring temperature through carbon fiber reinforced plastics requires an implanted contact-based temperature sensor during resistive heating. Implanting the sensor brings about considerable complications in the heat-joining of soft biocompatible Carbon Fiber Reinforced Plastics (CFRPs). In this paper, the concurrent temperature-dependent Electrical Resistance (ER) behavior of Carbon Fiber (CF) tow along with resistive heating is introduced. The temperature feedback from CF tow was investigated in the range of 60–200 °C in the room condition. The process is characterized by high nonlinearity due to complex mode of heat loss, orthotropic and semi-conductive nature of CF, resistivity of contacts, gas-moisture adsorption and ambient changes. In such conditions, experiments were conducted to study the Current-Voltage (I–V), ER-time and ER-temperature in steady-state and transient modes. I–V relationship was non-ohmic and ER-temperature relationship showed negative temperature coefficient at temperatures above 60 °C. Exponential behavior similar to that of thermistors was identified in ER-temperature relationship. The relationship is expressed by Hoge-quartic model, 1T=a+b(lnR(T))+c(lnR(T))2+d(lnR(T))3+e(lnR(T))4, showing the best fit among the conventional calibration equations of thermistor. The reversibility of ER-temperature relationship with maximum error of 16.4 °C was observed. The repeatability of the relationship shows the CF viability of providing concurrent temperature feedback during high-current Joule heating in the room condition.

A positive temperature‐dependent effect of elevated CO2 on growth and lipid accumulation in the planktonic copepod, Calanus finmarchicus

AbstractCalanus finmarchicus were reared from eggs to adults at 12°C and 16°C with non‐limiting food in combination with ambient (600 μatm) and high (1100 μatm) pCO2. These conditions are likely to be encountered by the species at the southern margins of its biogeographical range by the end of the century. Dry weight (DW), carbon (C) and nitrogen (N) mass, oil‐sac volume (OSV), fatty acid composition (FA), and oxygen consumption rates (OCR) were measured on newly molted stage CV copepodites and recently molted adult females. By focusing our measurements on these precise events in the life cycle, we were able to obtain a more accurate comparison of growth and respiration across treatments. Copepods raised at 12°C had a significantly greater DW, OSV, and C and N mass than those raised at 16°C High pCO2, independent of temperature, was associated with a further increase in the DW and C content of the copepods. Interactive effects of temperature and pCO2 resulted in a larger OSV at low temperature and high pCO2. Mass‐specific respiration rates were significantly lower at lower temperatures and elevated pCO2 suggesting that the increase in mass (DW, C, and OSV) resulted from reduced metabolic cost. The composition of fatty acids in the copepods varied mainly with temperature. Two fatty acids varied with pCO2: 16:0 tended to decrease with higher pCO2 and 18:3n−3 tended to increase with higher pCO2. These observations suggest that elevated pCO2/lower pH in future oceans may have a beneficial effect on C. finmarchicus.

Fine mapping of QTL for water use efficiency‐related traits on chromosome 9 of Solanum habrochaites in the field

AbstractFresh water is increasingly limited due to climate change. One way to reduce fresh water use by irrigated agriculture is to breed plants that can produce adequate yields with less water. A wild tomato, Solanum habrochaites, is more water stress tolerant than cultivated tomato, S. lycopersicum L. Our study aimed to fine map quantitative trait loci (QTL) for maturity, yield, and water use efficiency (WUE)‐related traits (shoot dry weight and carbon isotope discrimination, ∆13C) on chromosome 9 in S. habrochaites using a set of 21 sub‐near isogenic lines (sub‐NILs). These sub‐NILs and controls were evaluated in field experiments grown under full and reduced irrigation treatments across 2 yr. Genotype × environment interactions were significant, so the data was separated into subsets of environments for further analyses. Significant QTL were detected for 20 trait–environment combinations. All QTL were partially or completely coincident. The presence of the S. habrochaites allele at QTL was associated with later maturity, lower yields, and greater WUE. However, yield and ∆13C exhibited no or low correlations with each other, suggesting these traits could be selected for improvement independently during breeding. Two of 21 sub‐NILs showed superior performance for WUE and yield compared to controls. These two genotypes may prove useful in breeding programs to improve the WUE of tomato cultivars without negative effects on yield.

Dry ice propellant for electric propulsion with triple-point storage

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

Life cycle assessment of upcycling waste slag via CO2 pre-treatment: Comparative study of carbonation routes

Accelerated carbonation of industrial by-products such as yellow phosphorus slag (YPS) and basic oxygen furnace slag (BOFS) is an effective method to convert waste into valuable construction materials. Accelerated carbonation or CO2 sequestration can be conducted directly under dry or aqueous conditions. However, the slow reaction and low CO2 fixation efficiency of dry carbonation hinder the successful development of accelerated carbonation, whereas water consumption is the key challenge of aqueous carbonation for industrial applications. Therefore, this study evaluated the environmental impact of carbonation of YPS and BOFS via dry and aqueous routes, and upcycling these CO2-treated waste slags as cement replacements. The environmental impacts, including midpoint and endpoint impact, were quantified using life cycle assessment (LCA) by applying the ReCiPe methodology. The LCA results show that aqueous carbonation generates lower carbon emissions (11.3% and 214.0%) and human carcinogenic toxicity (2.4% and 0.2%) than dry carbonation for YPS and BOFS, but is accompanied by more serious impacts on mineral resource scarcity and water consumption. On the other hand, aqueous carbonation of BOFS generates lower (or even negative) carbon emissions than aqueous carbonation of YPS, and the same results can be found for human carcinogenic toxicity, mineral resource scarcity and water consumption. Sensitivity analysis shows that prolonged carbonation, particularly in the case of dry routes, results in very high carbon emissions. Apart from carbon emission benefits, using 20% aqueous carbonated YPS and 20% aqueous carbonated BOFS as cement replacements exhibited minimal impact of mechanical strength reduction, as compared with pure cement paste samples.

The abundance, biomass, and distribution of ants on Earth

Knowledge on the distribution and abundance of organisms is fundamental to understanding their roles within ecosystems and their ecological importance for other taxa. Such knowledge is currently lacking for insects, which have long been regarded as the "little things that run the world". Even for ubiquitous insects, such as ants, which are of tremendous ecological significance, there is currently neither a reliable estimate of their total number on Earth nor of their abundance in particular biomes or habitats. We compile data on ground-dwelling and arboreal ants to obtain an empirical estimate of global ant abundance. Our analysis is based on 489 studies, spanning all continents, major biomes, and habitats. We conservatively estimate total abundance of ground-dwelling ants at over 3 × 1015 and estimate the number of all ants on Earth to be almost 20 × 1015 individuals. The latter corresponds to a biomass of ∼12 megatons of dry carbon. This exceeds the combined biomass of wild birds and mammals and is equivalent to ∼20% of human biomass. Abundances of ground-dwelling ants are strongly concentrated in tropical and subtropical regions but vary substantially across habitats. The density of leaf-litter ants is highest in forests, while the numbers of actively ground-foraging ants are highest in arid regions. This study highlights the central role ants play in terrestrial ecosystems but also major ecological and geographic gaps in our current knowledge. Our results provide a crucial baseline for exploring environmental drivers of ant-abundance patterns and for tracking the responses of insects to environmental change.

Correlations of inclusion-based rock-physics model inputs from Bayesian analysis

AbstractFor any given rock-physics model, knowledge of correlations among its inputs helps to define geologically and physically meaningful and informed models for a given problem. These informed models can, in turn, reduce the uncertainty in forward and inverse problems. We use a Bayesian framework to identify such correlations among inputs of two rock-physics models. That framework makes use of velocity and porosity measurements on both dry and brine-saturated carbonate samples. Two inclusion-based rock-physics models, the self-consistent approximation and the differential effective medium model, are analyzed along with these data to identify the underlying correlations. To do so, the posterior distribution must be evaluated, which is based on a prior model and the calculated likelihood function. Exhaustive sampling of the posterior is convenient in this case because relatively few input parameters to consider. Results are multi-variate histograms that indicate maximum a posteriori values of the inputs. Correlations among the inputs become evident when the Bayesian analysis is repeated many times with different prior models. These correlated values provide the inputs to optimized maximum a posteriori models. The correlations identified for the two rock-physics models under study should be used in relevant applications. Finally, all rock-physics models, along with an appropriate data set, should be examined in a similar Bayesian framework.

THE ACTIVITY OF CEMENT?S COMPOUNDS IN CO2-HYDRATION HARDENING CONDITIONS FROM THE THERMODYNAMIC POINT OF VIEW

It was found that almost all the studied compounds could be carbonized under the influence of dry or wet carbon dioxide with the formation of calcium or magnesium carbonates. The equilibrium partial pressure of carbon dioxide or the equilibrium activity of the carbonate ion methods were used to evaluate carbonation reactions possibility. The activity of some minerals in carbonation reactions significantly exceeds the activity of the wollastonite and rankinite , which are used in Solidia?s clinker technolohy.

Changes in Dry Matter and Carbon, Nitrogen, and Sulfur Stocks after Applications of Increasing Doses of Pig Slurry to Soils with Tifton-85 for Six Years in Southern Brazil

Pig slurry (PS) has been used as soil fertilizer due to its nutrient and organic matter contents, which may improve soil nitrogen, carbon, and sulfur stocks. The objective of this work was to evaluate the best PS dose that favors the increase in dry matter production and carbon (C), nitrogen (N), and sulfur (S) contents and stocks after applications of PS to soils with Tifton-85 for six years. The experiment was conducted in a randomized block design with four replications, in a hay-producing area under a clayey Typic Hapludox in southern Brazil. The treatments consisted of annual applications of organic and mineral fertilizers at rates based on their N contents, using PS (100, 200, 300, and 400 kg ha−1) and urea (200 kg ha−1), and a control without N application. Samples of the soil in 0–5, 5–10, and 10–30 cm layers were collected in March 2019 and evaluated for soil bulk density and N, C, and S contents and stocks. The Tifton-85 dry matter production was evaluated using samples from three cuts carried out between 2012/2013 and 2017/2018 agricultural years. The applications of increasing doses of PS in Tifton-85 pastures over six years increase linearly the dry matter and soil organic C, N, and S stocks in the 0–30 cm layer. The PS rate equivalent to 100 or 200 kg ha−1 of N is recommended for increasing soil C, N, and S stocks, since it resulted in C, N, and S stocks equal to or higher than the control and mineral (urea) treatments.

Comparison of dry and liquid carbon dioxide cutting conditions based on machining performance and life cycle assessment for end milling GFRP

In the present scenario, citizens’ concern about environment preservation creates a necessity to mature more ecological and energy-efficient manufacturing processes and materials. The usage of glass fiber reinforced polymer (GFRP) is one of the emerging materials to replace the traditional metallic alloys in the automotive and aircraft industries. However, it has been comprehended to arise a sustainable substitute to conventional emulsion-based coolants in machining processes for dropping the destructive effects on the ecosystem without degrading the machining performance. So, in this study, the comparison of the two sustainable cutting fluid approaches, i.e., dry and LCO2, has been presented based on machining performance indicators like temperature, modulus of cutting force, tool wear, surface roughness, power consumption, and life cycle assessment (LCA) analysis for end milling of GFRP. The cutting condition of LCO2 has been found to be superior in terms of machining performance by providing 80% of lower cutting zone temperature, tool wear, 5% lower modulus of cutting force, and reduced surface roughness with 9% lower power consumption that has been observed in the case of LCO2 in comparison with dry machining. However, to compress the CO2 for converting in liquid form, a higher amount of energy and natural resources is consumed resulting in a higher impact on the environment in comparison with dry machining. Considering the 18 impact categories of ReCiPe midpoint (H) 2016, 95% higher values of impacts have been observed in the case of LCO2 in comparison with dry machining.