Search Results (391)

Two folding screens by futurist artist Giacomo Balla (1871–1958) in the collection of the Kröller-Müller Museum (the Netherlands) were investigated: Paravento con linea di velocità (1916–1917) and Paravento (1916/1917–1958). The screens are painted on both sides, the first on four canvases, stretched onto two wooden strainers and framed with painted wooden strips, and the second on wooden panels set into four painted stiles. In the past, damages on Paravento con linea di velocità were restored by conservators, while Paravento was probably first reworked by the artist himself and later restored by conservators. Yellowed varnish and discolored retouches on both screens led to a wish for treatment. The aim of this research was to gain insight into the painting techniques, layer buildup, pigments, binders, and varnishes of the two artworks. This information supported the decision making for treatment, and it broadens the knowledge on the materials used by Balla. Up to now, only a few published studies deal with the technical examination of paintings by this artist. Both folding screens were subjected to technical photography (UV, IR photography, and X-ray) and were examined with portable point X-ray fluorescence (pXRF) and Raman spectroscopy. Moreover, samples were taken. Cross-sections were studied with optical microscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), attenuated total reflection Fourier-transform infrared (ATR-FTIR) imaging, and micro-Raman spectroscopy. Loose samples were examined with SEM-EDX, FTIR and micro-Raman spectroscopy, and pyrolysis gas chromatography mass spectrometry (Py-GC/MS). For Paravento con linea di velocità, all pigments and fillers of the painted canvases are compatible with the dating of the screen (1916–1917), but they differ from those on the frame. Here, rutile, in combination with various pigments, among which are blue copper phthalocyanine (PB15) and other synthetic organic pigments, was found. This indicates that the frame has been painted later, likely after the Second World War. The composition of the binders differs as well. Drying oil and pine resin have been used on the canvases, explaining the smooth and glossy appearance and solvent-sensitivity of the paint. On the frame, oil with some alkyd resin was identified. The provenance of the screen before 1972 is not clear, nor when the frame was made and painted and by whom. The results for Paravento indicate that the palettes of the two sides—painted in different styles—are comparable. Mainly inorganic pigments were found, except for the dark red areas, where toluidine red (PR3) is present. pXRF showed high amounts of zinc; cross-sections revealed that zinc white is present in the lower layers. These pigments are compatible with the dating of the screen (1916–1917). In many of the upper paint layers though, except for some green, dark red, and black areas, rutile has been identified. This indicates that these layers were applied later, likely after the Second World War. Since this folding screen was used by the artist and his family until his death in 1958, it seems likely that Balla himself reworked the screen. Full article

Incomplete diesel combustion emits soot and CO. The use of biomass-derived, oxygen-containing diesel additives has been proposed as an effective mitigation strategy. Among these, long-chain ethers have been widely regarded as one of the most promising additive classes. Guided by this, carbonyl compounds were targeted as intermediates for the synthesis of long-chain ethers. Py-GC/MS was used to assess eight oxides (CaO, ZrO₂, NiO, CeO₂, TiO₂ (rutile), TiO₂ (anatase), Fe₂O₃, CuO) during fast pyrolysis of native holocellulose. Relative content of carbonyl compounds was increased by all catalysts, with CaO exhibiting the highest value (69.47%). CaO raised the content of linear ketones from 18.25% to 27.61%, while it sharply reduced the relative content of acetic acid (from 11.56% to 3.19%). TiO₂ (rutile) increased cyclic ketones from 11.09% to 15.01%. CuO boosted furans and acids to 17.48% and 17.91%, respectively. Levoglucosan dropped from 11.24% to 4.83% over CuO, which also increased furfural content from 3.25% to 5.63%. Full article

This study deals with the incorporation of biostimulants of natural origin in a biodegradable polymeric matrix, with the aim of developing mulch films that, when degraded in the soil, release bioactive compounds that improve soil quality and favor the agronomic growth of crops. Three types of commercial biostimulants were used: one based on seaweed extract, one on lignosulfonates, and one on plant-derived essential amino acids. To ensure the thermal stability of the biostimulant compounds during processing, thermogravimetric analyses (TGAs) were carried out, and a methodology based on the adsorption of the biostimulants onto porous substrates was developed, enabling their effective incorporation into the polymeric matrix. The formulations obtained have been processed by blown film extrusion at a pilot scale. In addition, the presence of film residues in soil was analyzed by pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS). The results indicate that the proposed methodology supports the integrity of the biostimulants in the films obtained. After the incubation period studied, complete degradation of the biopolymer and the absence of film residues in the soil were confirmed. Furthermore, it was confirmed that this final product had no adverse effects on organisms that were representative of the two end-of-life scenarios, with the exception of the film functionalized with the commercial biostimulant based on seaweed extract, which showed a negative effect on terrestrial higher plants. Full article

In response to the urgent need for sustainable energy solutions and efficient fossil resource utilization, the current research is conducted to examine the catalytic co-pyrolysis of four typical Chinese oil shales. The study assesses the ability of synergistic interactions, which are the result of organic and inorganic components, to improve the aspect of thermal behavior, decrease the activation energy and improve the shale oil quality. Thermogravimetric analysis in conjunction as Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS) and integral master-plots approaches showed that there were low activation energies and better reaction kinetics in blended systems. Fischer assay and GC-MS were utilized in product distribution and product composition evaluation, respectively. Optimization increased gas yield and oil composition stabilization in the blended gas, which is found due to the catalytic functions of AAEMs and clay minerals. This contribution facilitates the development of catalytic co-processing solutions where better conversion and reduced carbon intensity are achieved in the production of fossil-based energy. Full article

This study examines the swelling behaviour of nitrile-butadiene rubber (NBR) when interacting with tyre pyrolysis oils (TPO), with a focus on the chemical composition of TPO and their interaction with rubber matrices. Initially, a comparative analysis with conventional diesel fuel (DF) was performed using advanced analytical techniques, including two-dimensional gas chromatography coupled to mass spectrometry (2D-GC/MS), infrared (IR) spectroscopy, and nuclear magnetic resonance (¹H-NMR) spectroscopy. The analysis revealed that TPO contains a significantly higher proportion of aromatic hydrocarbons than DF, along with unsaturated and oxygen-containing compounds not present in DF. Based on these compositional differences, blends of TPO and DF were formulated and evaluated for their suitability as liquid energy carriers according to the specifications of DF. In principle, blends with an addition of up to 5 vol% TPO in DF are technically suitable for use as fuel. Subsequently, the sorption behaviour of TPO, DF, and their blends in NBR was investigated. The swelling potential was determined based on mass, density, and volume, and the changes in the hardness and tensile strength of NBR were recorded. The results demonstrate that TPO induces pronounced swelling in NBR, as evidenced by a marked increase in mass uptake and volume expansion. A linear increase was observed between the degree of swelling and the increasing TPO content in the blends. Mechanical property assessments revealed a corresponding decrease in the hardness and tensile strength of NBR upon exposure to TPO, with the most severe effects associated with neat TPO. This work provides a comprehensive assessment of TPO as a potential blend component for DF. It highlights the need for careful consideration of material compatibility in practical applications. Full article

In recent years, research in the field of the sustainable production of refractory ceramics has become topical. Significant attention has been paid to the use of secondary raw materials for obtaining high-quality materials. The purpose of the current study was to develop new high-temperature porous materials based on the magnesium sulfate-refractory clay–chamotte–aluminum system using environmentally friendly raw components. To synthesize porous refractories, rice husk and the by-products of its thermal processing were used as substitutes for ingredients usually introduced into the composition of high-temperature materials. Ground rice husk was used as both a burnout additive and a silica source. It was added to the mixture instead of chamotte. An organic condensate from rice husk pyrolysis was used as a binder. A sodium silicate solution, after activating pyrolyzed rice husk with alkali, was also tested as a binder. These liquid ingredients served as replacements for lignosulfonate and liquid glass. The new raw material components and the porous refractories obtained with their use were studied using methods of chemical analysis, XRD, GC-MS, TA, SEM, and EDS. Standard methods for studying the properties of refractories were used to evaluate the physicomechanical and thermal characteristics of the experimental materials. The sample with the maximum content of rice husk (14.4 wt.%) and organic condensate from its pyrolysis (10.5 wt.%) demonstrated promising properties as a light porous refractory: an apparent porosity of 44%, a volumetric weight of 1.1 g·cm⁻³, compressive strength of 2.1 MPa, tensile strength in bending of 4.5 MPa, bond strength of 0.01 MPa, thermal shock resistance of 155 thermal cycles, and thermal conductivity of 0.05 W (m·K)⁻¹. It can be used as a prospective thermal insulating material. Full article

Microplastics (MPs) are a ubiquitous marine pollutant, and their presence in bivalves is receiving increasing attention due to the associated risks to human health. The steps of pretreatment, detection, and quantification in the analysis of MPs depend on the type of polymer. Research on MPs is challenging because of the varying characteristics of these materials, such as the size, shape, and polymer type. Consequently, there are no standardized methods for their collection, separation, identification, or quantification. This review specifically examines the available bivalve digestion steps, focusing on efficient and time-reducing methods, such as the microwave-assisted (MAW) procedure and its advantages. Recent achievements in the application of pyrolysis gas chromatography–mass spectrometry (Pyr-GC-MS) are presented for the profiling of polymer mass-related microplastics data in marine bivalves. Here, we provide an overview of the abundance, properties, and polymer types of MPs in bivalve species, highlighting the polymer mass fractions. To date, the available mass-based concentrations have revealed nine types of MPs—polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polystyrene (PS), polymethyl methacrylate (PMMA), polyamide 66 (PA66), polycarbonate (PC), and polyamide 6 (PA6)—with PE, PP, and PVC being the most common. The total MP levels in bivalves were at ppm levels, ranging from 0.26 µg/g to 36.4 µg/g wet weight. The risk of human ingestion of MPs was assessed through the consumption of bivalves as seafood. The overall potential human health risk value (H) for marine bivalves was classified within the moderate to high hazard category. Full article

Pyrolysis of 24 samples of foliage from three U.S. regions with frequent wildland fires (Southeastern U.S., northern Utah and Southern California) was studied in a fuel-rich flat-flame burner system at 765 °C (for Southeastern U.S. samples) and 725 °C (for northern Utah and Southern California species), with a heating rate of approximately 180 °C/s. These conditions were selected to mimic the conditions of wildland fires. Individual plant samples were introduced to the high temperature zone in a flat-flame burner and pyrolysis products were collected. Tar was extracted and later analyzed by GC/MS. Light gases were collected and analyzed by GC/TCD. The estimated range for the average yields of tar and light gases were 48 to 62 wt% and 18 to 31 wt%, respectively. Apart from Eastwood’s manzanita (Arctostaphylos glandulosa Eastw.), aromatics were the major constituents of tar. The variations in the concentrations of tar compounds likely resulted from differences in biomass composition and physical characteristics of the foliage. The four major components of light gases from pyrolysis (wt% basis) were CO, CO₂, CH₄ and H₂. Tar contributed more than 82% of the high heating value of volatiles. These data can be used to improve physical-based fire propagation models. Full article

Understanding the microscopic occurrence states of shale oil—particularly the distribution between adsorbed and free phases—is essential for optimizing the development of unconventional reservoirs. In this study, we propose an integrated methodology that combines experimental techniques with molecular dynamics simulations to investigate shale oil behavior within kerogen nanopores. Specifically, pyrolysis–gas chromatography–mass spectrometry (PY-GC-MS), solid-state ¹³C nuclear magnetic resonance (¹³C NMR), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) were performed to construct a representative kerogen molecular model based on shale samples from the Lianggaoshan Formation in the Sichuan Basin. Grand Canonical Monte Carlo (GCMC) simulations and a theoretical occurrence model were applied to quantify the adsorption characteristics of n-dodecane under varying pore sizes, temperatures, and pressure. The results show that temperature exerts a stronger influence than pore diameter on adsorption capacity, with adsorption decreasing by over 50% at higher temperatures, and pressure has a limited effect on the adsorption amount of dodecane molecules. This study offers a robust workflow for evaluating shale oil occurrence states in complex pore systems and provides guidance for thermal stimulation strategies in tight oil reservoirs. Full article

Thermal degradation of polydimethylsiloxane (PDMS)-based silicone sealants was investigated using evolved gas analysis (EGA) for rapid temperature screening, combined with multistep pyrolysis gas chromatography with mass spectrometric detection. The identified products were cyclic siloxanes, ranging from hexamethyl cyclotrisiloxane to hexadecamethyl cyclooctasiloxane. Aged and weathered sealants showed distinctly lower siloxane evolution temperatures (450–510 °C) compared to fresh samples (610–710 °C), indicating more facile polymer degradation. This trend was evident in both EGA-MS and Py-GC-MS, with EGA-MS showing a more pronounced effect, suggesting its potential for detecting sealant failure. Notably, the total evolved amounts of specific siloxanes remained nearly constant, suggesting that weathering primarily affects the thermal evolution profiles rather than the overall PDMS structure. The abundance of the three largest-size siloxanes increased (3–7%) with the weathering; in contrast, the changes in the amounts of the most abundant siloxanes were insignificant throughout all samples, regardless of the extent of weathering. These observations suggest that weathering induces changes in details of material structure, e.g., intermolecular interactions, rather than substantial chemical alterations to the PDMS structure. Full article

Coal pyrolysis and gasification are among the key technologies for the clean and efficient utilization of coal. This work examined the individual and synergistic effects of Na and CO₂ on gas/tar generation during rapid coal pyrolysis using a fixed-bed reactor integrated with gas chromatography–mass spectrometry (GC-MS) and a flue gas analyzer. Key findings reveal that Na, CO₂, and Na/CO₂ synergism increased total gas volume by 671 vol.%, 772 vol.%, and 667 vol.%, respectively, while reducing tar yields by 4.14%, 3.12%, and 7.15%. Light oil yields reached 27.18%, 27.93%, and 40.35% under corresponding conditions. Crucially, Na significantly enhanced CO and CH₄ release (dose-dependent), with low-concentration Na (1–3%) promoting light-component condensation versus high-concentration Na (5%) facilitating heavy-component cracking. Na/CO₂ synergism intensified heavy-component fragmentation (efficacy increasing with Na loading), while low-concentration Na (1–3%) substantially boosted CO yield, highlighting its potential for selective syngas modulation. This work plays a pivotal role in advancing the low-emission, high-efficiency utilization of coal energy, aligning with global carbon reduction strategies. Full article

In 2021, archeologists found that a bronze mirror was wrapped with a yellow-green fiber sheet in the Western Han tomb M68 in the Dabuzi Cemetery in Xi’an, China. To ascertain the composition and function, a scanning electronic microscopy–energy dispersive spectrometer (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), and pyrolysis gas chromatography–mass spectrometry (Py-GC/MS) were combined for the morphology and components’ analysis. The results showed that the surface of the yellow-green fiber sheet was very rough without curtain patterns, and the fiber was disorderly intertwined. The paper was quite thick with various thicknesses (the average thickness was 0.58 mm) and the average diameter of the fiber was 20.71 μm. There were obvious transverse joint stripes on the fiber cell with longitudinal stripes characteristic of ramie or hemp. The main ingredients were cellulose, semi-cellulose, and lignin. Based on the above comprehensive joint experiments, the yellow-green fiber sheet in M68 was presumably ancient hemp paper made with the fixed-mold method. Moreover, it was speculated to be a package material since no characters were found. This paper is of great significance for studying the Chinese fixed-mold paper-making technique and for understanding the origins and developmental trajectory of ancient paper-making technology. Full article

Nanocellulose has attracted significant attention in recent years due to its distinctive properties and vast potential applications across various fields. This study encompasses two distinct yet interconnected activities: the characterisation of eight different types of nanocellulose test materials, including crystalline, fibrillated, and bacterial nanocellulose, using a range of analytical techniques such as dynamic light scattering (DLS), asymmetric flow field-flow fractionation (AF4) coupled to multi-angle light scattering (MALS) and DLS, and transmission electron microscopy (TEM), and a focused case study employing a tiered analytical approach to identify bacterial nanocellulose in commercially available food products like pudding and drinks with nata de coco, SCOBY, and kombucha. The results demonstrate that different types of nanocellulose can be distinguished by their unique physicochemical properties using a combination of analytical techniques. This finding was used for the identification of bacterial nanocellulose in food products by combining pyGC-MS for cellulose identification, TEM for nanosize range determination, and XRD for crystallinity analysis to distinguish between bacterial and fibrillated nanocellulose. The study advances fundamental understanding of nanocellulose and provides tools to facilitate potential future regulatory compliance. Full article

The paper presents the effect of an organic solvent on the efficiency of vapor condensation from pyrolysis processes applied to agricultural waste, with the intention of optimizing the trapping procedure for more volatile components. Therefore, the effect of the use of acetone in the vapor trapping system on the yield and composition of liquid fractions (bio-oils) obtained from the pyrolysis of selected agricultural waste, including corn, tomato, and tobacco, was investigated. The focus was placed on evaluating how solvents influence the quality, yield, and composition of bio-oil, as well as whether they are necessary in the pyrolysis process. Acetone, a polar solvent with low human toxicity and the possibility of regeneration after pyrolysis, was selected for bio-oil condensation due to its effectiveness in dissolving polar compounds formed during the pyrolysis of lignocellulosic biomass. Pyrolysis was conducted at 400 and 500 °C for 30 min, to collect light and heavy fractions, which were subsequently analyzed to assess acetone’s influence. The results showed that acetone positively affected corn bio-oil yield (from 44.57% without acetone to 52.13% with acetone) and improved quality by reducing moisture (from 61.82% to 12.83%) and oxygen content (from 86.50% to 47.10%). An increase in calorific value was also observed in both corn varieties, while the effect was minimal in tobacco and nearly negligible in tomato. The obtained parameter values indicated that satisfactory results can also be achieved without the use of a solvent, representing a step toward simplified pyrolysis. GC-MS analysis confirmed that phenols and their derivatives were the dominant compounds, while FTIR analysis verified the presence of functional groups of the identified compounds. Increasing the temperature generally increased both the yield and calorific value of most samples. Light and heavy fractions were separated during condensation to improve collection efficiency and enable better quality control. Although this step adds complexity and potential contamination risks, it allows more effective utilization of the fractions. These results provide a valuable foundation for optimizing the valorization of agricultural waste through pyrolysis-based biofuel production. Full article

The Chengyang City (城阳城) site in Xinyang, Henan Province, China, was a significant northern military stronghold of the Chu state during the Warring States period (475/403–221 BCE). The lacquered armor unearthed from Tomb M18 provides critical material evidence for studying ancient military technology and lacquer craftsmanship. In this study, a comprehensive analytical approach combining ultra-depth optical microscopy, Fourier-transform infrared spectroscopy (FTIR), confocal micro-Raman spectroscopy, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS) and pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS) were employed to systematically characterize the structural and compositional features of the armor samples. The results indicate that the armor was constructed with a leather substrate and lacked any lacquer ash layer, while the surface exhibited multiple layers of mixed laccol and urushiol-based lacquer coatings. Cinnabar (HgS) was identified as the primary red pigment, and no carbon black or iron-based blackening agents were detected in the dark lacquer layers. Notably, the presence of laccol suggests that such lacquer resources may have also been produced in mainland China, offering new perspectives on the prevailing view that associates laccol exclusively with “Vietnamese lacquer.” This study elucidates the technological characteristics of mid-Warring States period lacquered armor, provides scientific insights into ancient lacquering techniques, and contributes valuable data for the conservation and restoration of similar cultural heritage artifacts. Full article