Joeri Kaal

Joeri Kaal
Pyrolyscience

PhD

About

122
Publications
23,418
Reads
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3,234
Citations
Introduction
Molecular characterization of natural organic matter from soils, sediments, archaeological artifacts, biological materials, biochar, black carbon, etc. Palaeoecology. Pyrolysis techniques. IF YOU'RE INTERESTED IN THIS RESEARCH AND IN APPLYING ANALYTICAL PYROLYSIS TECHNIQUES YOURSELF, CONTRACT THE SERVICES OF WWW.PYROLYSCIENCE.COM.
Additional affiliations
May 2005 - December 2012
Spanish National Research Council
Position
  • Researcher
April 2019 - present
Technische Universität Braunschweig
Position
  • PostDoc Position
Description
  • DFG project on DOM dynamics in the Harz Mountains (50 % part-time position)

Publications

Publications (122)
Article
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Charred aggregates are one of the most common forms in which millets are preserved on archaeological sites. Despite the lack of consensus on their origin, few studies have attempted to determine how aggregates are formed. Knowing how aggregates are produced allows us to understand the diversity of processes operating in the formation of charred arc...
Article
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Findings of archaeological textiles and fibres in Northern Iberia are extremely rare. The occurrence of a set of textile fragments, dated between the 14th and 16th centuries CE at the Pambre castle (Palas de Rei, Lugo, Spain) is exceptional. The original stone roof of the southeastern tower was intact. The dark, cold and moist conditions inside the...
Article
In Europe, especially the Low Countries, peat was intensively used as a fuel source. Yet, the identification of peat as a fuel source from archaeological combustion residues is challenging. Nevertheless, detecting peat fuel in archaeological contexts would significantly contribute to broader socioeconomic questions, such as fuel and landscape manag...
Article
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Wildfire ash can have an impact on coastal prokaryotic plankton. To understand the extent to which community composition and abundance of coastal prokaryotes are affected by ash, two ash addition experiments were performed. Ash from a massive wildfire that took place in the Ría de Vigo watershed in October 2017 was added to natural surface water sa...
Article
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The Holocene climate history of Southern Africa remains inconclusive despite the increasing number of proxy records from the region. This might be related to the diversity of proxy records, how the proxies are interpreted, or that proxies may respond to more than one forcing (e.g. hydroclimate, fire, temperature.). Here, a 175-cm peat sequence from...
Article
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We explored the potential of pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) as a molecular characterization tool for paper envelop materials in nests of the Asian hornet (Vespa velutina Lepeletier, 1836), a runaway invasive species in Western Europe. The area of study is the NW of the Iberian Peninsula (Galicia, A Coruña province) and th...
Chapter
Caves are frequent in some granite massifs, that are very common in the NW of the Iberian Peninsula. Water trickling through joints and discontinuities of granitic massifs is the cause of the formation of speleothems that have been related to the biological activity of several organisms. They can be usually found in the water output of fissures, sh...
Article
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This paper deals with the so-called modular kilns, ceramic structures characteristic of the Bronze and Iron Age periods in various regions of Europe. Despite the interest shown in these material forms in recent years, their exact function is still unclear. However, the dominant interpretation within archaeological research has tended to associate t...
Preprint
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Peatlands are important carbon sinks due to their ability to sequester and store large amounts of carbon in the form of organic matter (OM). The microhabitat levels and species distribution within peatlands can significantly influence the mechanism of carbon sequestration, and the quality of OM in moss, specifically its litter, may be a key factor...
Article
The transformation of sapwood (SW) into heartwood (HW) during ageing of wood tissues is the result of physiological and biochemical changes initiated in the transition zone (TZ). These changes contribute to the evolution of active (living) wood cells in SW into less/non-active (dead) wood cells in HW. Previous studies established that the biosynthe...
Article
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Aims Soil warming significantly influences soil organic carbon (SOC) pools in terrestrial ecosystems through its impact on the processes of carbon (C) input and decomposition as well as the stabilization of SOC pools. Most studies demonstrated that soil warming reduces SOC pools, but the magnitude is highly variable, and the underlying mechanisms a...
Preprint
Full-text available
This paper deals with the so-called modular kilns, ceramic structures characteristic of the Bronze and Iron Age periods in various regions of Europe. Despite the interest shown in these material forms in recent years, it is still unclear what their function was exactly. However, the dominant interpretation within archaeological research has tended...
Preprint
Full-text available
This paper deals with the so-called modular kilns, ceramic structures characteristic of the Bronze and Iron Age periods in various regions of Europe. Despite the interest shown in these material forms in recent years, it is still unclear what their function was exactly. However, the dominant interpretation within archaeological research has tended...
Article
There is a need for tools to determine the origin of organic matter (OM) in Blue Carbon Ecosystems (BCE) and marine sediments to (1) facilitate the implementation of Blue Carbon strategies into carbon accounting and crediting schemes and (2) decipher changes in ecosystem condition over decadal to millennial time scales and thus to understand and pr...
Article
Peatlands of the Northern Hemisphere and Central European coniferous forests experience significant environmental change. The resultant browning of surface waters, that is, elevated concentrations of dissolved organic matter (DOM) and metals, is of interest in the context of the global C cycle, peatland and forest management, and water treatment. I...
Article
The chemical composition of the seawater soluble fraction (WSF) of yellow-legged gulls and harbour seal faeces and their impact on microbial plankton communities from an eutrophic coastal area have been tested. After characterisation of the C:N:P stoichiometry, trace metals content and organic molecular composition of the faeces, significant differ...
Article
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PurposeSilicon (Si) is a beneficial element for plants and plays important roles in the biogeochemical cycle of mineral elements. Yet, few studies have focused on the impact of nitrogen (N) deposition on plant Si uptake and the Si biocycle.Methods We designed an experiment investigating canopy and understory N addition in a tropical forest to compr...
Article
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Ceramic fragments from the Islet of Guidoiro Areoso (NW Spain), covering a wide range of cultural periods (Neolithic to Late Bronze Age), have been studied by color analysis, elemental analysis of carbon (C) and nitrogen (N), and molecular analysis (thermally assisted hydrolysis and methylation, THM-GC-MS), in order to identify the organic matter (...
Article
The quantity and quality of dissolved organic matter (DOM) in the brine of solar ponds influence the efficiency of mineral extraction and brine evaporation rates. Here we report a characterization study of DOM in solar ponds of oilfield-produced brines using different approaches. The results showed that the concentrations of dissolved organic carbo...
Article
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Cadmium, Cu, Ni, Pb, and Zn removal via soil flushing with tannic acid (TA) as a plant biosurfactant was studied. The soil was treated for 30 h in a column reactor at a constant TA concentration and pH (3%, pH 4) and at variable TA flow rates (0.5 mL/min or 1 mL/min). In the soil leachates, pH, electrical conductivity (EC), total dissolved organic...
Article
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Store Mosse (the ‘Great Bog’ in Swedish) is one of the most extensive bog complexes in southern Sweden (~77 km2), where pioneering palaeoenvironmental research has been carried out since the early 20th century. This includes, for example, vegetation changes, carbon and nitrogen dynamics, peat decomposition, atmospheric metal pollution, mineral dust...
Article
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Speleothems are a recognized source of palaeoclimatic information, but their value as a source of signals from human activities in caves with an archaeological record has rarely been explored. Previous studies of speleothems in the Sierra de Atapuerca karst system (Burgos, northern Spain) revealed an important human fossil record, provided informat...
Article
Waterlogged woodcrafts and other plant remains were recovered at 65 Arcebispo Malvar Street (Pontevedra, Spain) from contexts from the 13th to 19th centuries AD, although most of the artefacts were concentrated in accumulations of organic remains dating to the 15th century AD. The site is located close to the harbour (Peirao da Ponte) and the woode...
Article
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Granite massifs often contain caves, with dimensions ranging from a few meters up to 1,000 m, also referred to as pseudokarst. The speleothems in such caves are mostly composed of either Si-rich (commonly opal-A) or Al-rich authigenic mineraloids. Whereas the formation and geochemical composition of opal-A biospeleothems have been studied and are f...
Article
Environmental change is increasing the concentration of dissolved organic matter (DOM) in catchments of the Northern Hemisphere. This study aims to assess the causes of high DOM concentrations in streams and reservoirs of the Harz National Park (Germany), by means of molecular characterization using thermally assisted hydrolysis and methylation (TH...
Article
Carbon stocks in coastal vegetated ecosystems account for half of the carbon in marine sediments and soils. Disturbance in these ecosystems can release vast amounts of carbon through mineralization, depending on poorly understood factors such as soil organic matter (SOM) quality and environmental factors. The meadows of the seagrass Posidonia ocean...
Article
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While the use of fire has long been recognised as a crucial innovation in the cultural evolution of humankind, much research has focused on the (debated) chronology of its earliest use and control, and less on the ways in which fire was used in the deep past. At its latest by the Upper Palaeolithic, hunter-gatherers routinely used fire to heat a wi...
Article
This research presents for the first time a comprehensive study of charcoal directly related to the multiple burials interred in Tomb 2 of El Caño (Coclé province, Panama). This funerary context, which dates to between AD 880 to AD 1020, contained three different burial levels accompanied by substantial ceramic offerings and rich mortuary assemblag...
Article
Seagrass ecosystems, which have important functions such as coastal protection and blue carbon sequestration, are threatened by anthropogenic pressure including climate change. Long-term data series from seagrass sedimentary archives (mats) can be used to understand natural cycles of environmental change and answer key questions related to contempo...
Article
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Lignins from different parts of the seagrass Posidonia oceanica –namely sheaths, rhizomes, and roots– as well as from fibrous balls from P. oceanica detritus were isolated and thoroughly characterized by Pyrolysis coupled with Gas Chromatography/Mass Spectrometry (Py-GC/MS), Derivatization Followed by Reductive Cleavage (DFRC), two-dimensional Nucl...
Article
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Blue carbon ecosystems (BCE) play an essential role in the global carbon cycle by removing atmospheric carbon dioxide and storing it as organic carbon (OC) in biomass and sediments. However, organic matter (OM) deposition and degradation/preservation processes are poorly understood, especially on the long-term and at molecular scales. We analysed s...
Article
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Streams and reservoirs in the Harz National Park experience high dissolved organic matter (DOM) concentrations, the cause of which is unknown. We studied potential sources of DOM by means of pyrolysis-GC-MS (Py-GC-MS). The biological materials include vegetation samples (spruce, birch, blueberry, heather, sedge, grass, peat moss, epiphytic moss), m...
Article
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This research aimed to determine the origin of organic residues from funerary contexts in the El Caño settlement (Gran Coclé area, Panamá, Central America) by means of multiple molecular probing techniques (GC-MS of organic solvent extracts and pyrolysis-GC-MS, THM-GC-MS and FTIR of solid samples). The samples include particles of precious resin fi...
Article
Soil dissolved organic matter (DOM) plays an essential role in the Three Gorges Reservoir (TGR) as a linkage between terrestrial and aquatic systems. In particular, the reducing capacities of soil DOM influence the geochemistry of contaminants such as mercury (Hg). However, few studies have investigated the molecular information of soil DOM and its...
Article
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At the Neolithic site Bastuloken, several subterranean embankments have been identified. The corresponding sediments contain large amounts of bones and lithic elements, indicative of not only massive hunting but possibly also a large (elk) skin processing plant. The present study uses analytical pyrolysis and in-frared spectroscopy to track changes...
Article
The Pago Lindo site in the River Plate basin (Uruguay) is an important pre-hispanic mound settlement (ca. 3000–600 BP), of which the technologically and socially advanced nature have only recently been revealed. Different angles of pedogenetic and palaeo-ecological science are rapidly improving our understanding of the history of the site and the r...
Article
Seagrass ecosystems are recognised for their role in climate change mitigation, due to their capacity to form organic-rich sediments. The chemical recalcitrance of seagrass organs is one characteristic driving carbon storage, but the molecular background of this feature is poorly understood. We assessed molecular composition changes of Posidonia au...
Article
Soil dissolved organic matter (soil DOM) plays a crucial role in the environmental fate of pollutants because of its exceptional biogeochemical reactivity. Therefore, tracing the sources and understanding the properties of DOM through chemical characterization is important for clarifying the "structure-reactivity" of DOM in the environment. In this...
Conference Paper
Full-text available
Findings of archaeological and historical textiles and fibres in northwest Iberia are rare. The occurrence of a set of textile fragments, dated between the 14th and 16th centuries AD, in the Pambre castle is exceptional. The textile remains were recovered from different areas of the castle -the southeast tower and the main area of the castle among...
Article
Full-text available
Blue carbon is the organic carbon in oceanic and coastal ecosystems that is captured on centennial to millennial timescales. Maintaining and increasing blue carbon is an integral component of strategies to mitigate global warming. Marine vegetated ecosystems (especially seagrass meadows, mangrove forests, and tidal marshes) are blue carbon hotspots...
Article
We studied the seasonal fluctuations in the composition of sinking particulate organic matter (POM) in the only upwelling-affected continental margin of Europe, to improve our understanding of the carbon (C) cycle of such systems. The methods employed targeted the elemental, stable isotope (δ¹³Coc and δ¹⁵N) and molecular (Py-GC-MS) composition. The...
Article
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This contribution outlines applications of analytical pyrolysis techniques (APTs)-in particular pyrolysis-gas chromatography-mass spectroscopy (Py-GC-MS) and thermally assisted hydrolysis and methylation (THM-GC-MS)-to marine geochemical research. It is subdivided into two main lines, i.e. the results obtained from (1) sedimentary, particulate and...
Article
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Organohalogens in the environment are a booming research subject, due to their role in many ecosystem functions and ecotoxicology. A recent study showed that a series of colluvial soils in NW Spain, known as Atlantic rankers and having the idiosyncratic feature of high loads of aged pyrogenic soil organic matter (SOM) from anthropogenic palaeofires...
Article
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Geoarchaeological surveys in South Germany (Nördlinger Ries area) showed continuous presence of human occupations since the Palaeolithic and remarkable colluvial soils containing dark buried layers dated to the Neolithic. Here we discuss molecular properties of soil organic matter (SOM) from three of these colluvia by Py-GC-MS. The pyrolysis produc...
Article
Archaeological wood fragments from four Iberian shipwrecks (Belinho, Magdalena, Ribadeo and Yarmouth) and living tree cores of four oak species (Quercus faginea, Quercus petraea, Quercus pyrenaica and Quercus robur) were analysed by Fourier Transform Infrared spectroscopy (FTIR) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). The use...
Article
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We present the process of restoration and analysis of pigments in the painting El Arrepentimiento de San Pedro by Francisco Collantes, a Baroque painter from the 17th century. The restoration process allowed the recovery of the splendor of this work, which will be exhibited permanently in the Museo de Belas Artes de A Coruña. The chemical analysis...
Article
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Data in this article are related to the chemical characterization of various oak wood samples. Data have been obtained by the application of Fourier Transform Infrared (FTIR) spectroscopy and pyrolysis-gas chromatography-mass spectrometry (Py–GC–MS) to living tree species and shipwreck wood fragments. Measurements were performed on individual rings...
Article
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The Galician coastline is enormously productive of high-quality seafood due to the vast supply of nutrients , oxygen and plankton in this unique coastal up-welling system 1. One of the characteristics of the Rías is the abundance of raft farms, "bateas": floating wooden structures with 500 ropes hanging into the water column and on which mussels gr...
Article
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Itla-okla, which means "tree hair", was the Indian name of the epiphyte Tillandsia usneoides, also known as "Spanish beard" or "Spanish moss". Pre-Columbian societies of the Late Archaic period (Orange and Stallings traditions; 3000-1800 B.C.) used these epi-phytes as an organic temper in the production of pottery. In collaboration with Zackary Gil...
Article
There is considerable variability in the ability of seagrass ecosystems to sequester organic carbon (Corg) in their sediments, which act as natural carbon sinks contributing to climate change mitigation. In this work, we studied the chemistry of two Posidonia seagrass species aiming to elucidate whether differences in chemical composition might exp...
Article
This paper evaluates the complexities of radiocarbon ( ¹⁴ C) dates from soil organic matter (SOM) in archaeological scenarios. The aqueous NaOH-insoluble residual SOM from Neolithic to medieval sites in NW Spain produced consistently older calibrated ¹⁴ C ages than NaOH-extractable SOM. Using pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS...
Preprint
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Como parte del estudio de los objetos arqueológicos del sitio arqueológico de El Caño (provincia de Coclé, Panamá), hemos creado una colección de referencia de elementos de la vegetación local que son particularmente prolíficos en exudados (resinas y gomas). Estas muestras fueron analizadas por cromatografía de gases en combinación con espectrometr...
Article
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Peatlands in northern latitudes sequester one third of the world's soil organic carbon. Mineral dusts can affect the primary productivity of terrestrial systems through nutrient transport but this process has not yet been documented in these peat-rich regions. Here we analysed organic and inorganic fractions of an 8900-year-old sequence from Store...
Article
The Middle and Late Uruk period (3600-3100 BC) is characterised by the diffusion of the Uruk culture in Mesopotamia and surroundings. Uruk sites are recognised by a special kind of pottery called bevelled rim bowls (BRBs), which comprise up to 80% of all recovered Uruk pottery. BRBs are very basic, handmade bowls produced in large quantities but th...
Presentation
Full-text available
ARCH-BOT: II Ciclo de conferencias en arqueoloxía e arqueobotánica Coordina: María Martín-Seijo (GEPN-AAT.USC) Inscrición previa: maria.martin.seijo@usc.es
Article
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Attenuated total reflectance-Fourier transform infrared (FTIR-ATR) spectroscopy was applied to 120 samples of heartwood rings from eight individual pine trees from different locations in Spain. Pinus sylvestris cores were collected at the Artikutza natural park (Ps-ART). Pinus nigra cores were collected in Sierra de Cazorla (Pn-LIN) and in La Sagra...
Article
Pleistocene yedoma sediments store large amounts of soil organic matter (SOM) and are vulnerable to permafrost degradation. Here we contribute to our understanding of yedoma SOM dynamics and potential response to thaw, by molecular characterization of samples from a 5.7 m yedoma exposure, as well as upper permafrost samples that were previously inc...
Article
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A recent paper in Organic Geochemistry entitled "Radi-cally different lignin composition in Posidonia species may link to differences in organic carbon sequestration capacity" discusses the remarkable difference in lignin chemistry between two kinds of "Neptune grass", i.e. Posidonia oceanica and Posidonia australis. Analytical Pyrolysis Letters AP...
Article
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Pyrolysis-gas chromatography-mass spectrometry (Py-GC–MS) and thermally assisted hydrolysis and methylation (THM-GC–MS) were applied to 27 coal samples of lignite to high volatile bituminous rank (vitrinite reflectance %Ro =0.28–0.66) from the Malaysian states of Sabah and Sarawak on Borneo, to investigate rank effects on molecular properties. The...
Conference Paper
Full-text available
The Galician coast (Northwest Spain) is irregular and contains several estuaries that form natural ports (Solórzano 2009). Pontevedra’s harbour is placed at a natural shelter in the Lérez river mouth, a place with defensive advantages and protection from the wind. Pontevedra had a commercial wharf, Peirao da Ponte, built in 1339 located inside the...
Article
Fourier-transform infrared spectroscopy (FTIR), conventional analytical pyrolysis (Py-GC-MS) and thermally assisted hydrolysis and methylation (THM-GC-MS) were applied to lyophilized dissolved organic matter (DOM) samples taken along a small river (Oder river, Harz Mountains, Germany) draining a peatland and an adjacent spruce forest to study sourc...
Article
Full-text available
Even though pyrolysis in combination with gas chromatography and mass spectrometry (Py-GC-MS) is widely used for molecular characterization of wood, its abilities to determine the taxonomy (species), provenance and the nature and intensity of degradation of archaeological woods are hardly explored. We performed principal component analysis (PCA) on...
Article
Soil-derived dissolved organic matter (DOM) has a major influence in biogeochemical processes related to contaminant dynamics and greenhouse gas emissions, due to its reactivity and its bridging role between the soil and aquatic systems. Within the Three Gorges Reservoir (TGR, China) area, an extensive water-fluctuation zone periodically submerges...
Article
Biochar thermosequences produced from the charring of poultry manure and freshwater macroalgae feedstocks between 300 and 700 °C were analyzed by pyrolysis-GC-MS to assess the nature of the thermochemical conversion of N-rich feedstocks. With increasing charring temperature (TCHAR), the products of intact lignin, protein and polysaccharides decreas...
Article
Before the invention of modern, large-scale engineering projects, terrace systems were rarely built in single phases of construction, but instead developed gradually, and could even be said to have evolved. Understanding this process of landscape change is therefore important in order to fully appreciate how terrace systems were built and functione...
Article
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We applied common (pH, elemental analysis, thermogravimetry) and less-common (infrared spectroscopy, GACS adsorption test, pyrolysis-GC-MS, hydrogen pyrolysis) analytical procedures to a set of biochars from Costa Rica (bamboo stalk, cacao chaff, sawmill scrap, coconut husk and orchard prunings feedstocks). The biochars were produced by high temper...
Conference Paper
Full-text available
We applied principal component analysis to the transposed data matrix (PCAt) of FTIR spectra to determine the effects of storage condition on archeological wood composition. Sixty FTIR-ATR spectra were taken from three pine wood cores (one from a living tree and two from archaeological wood) to characterize within and between samples variability. T...
Article
The study of the gold earrings from the Recouso treasure (NW Iberia) led us to identify the use of non-metallic fills in the manufacturing process. This article offers an initial characterisation of these core materials and discusses their possible purpose. Based on the identification of diatom skeletons in the fill of one earring and the Py-GC-MS...
Article
Analytical techniques to assess the degree of alteration of pyrogenic black carbon (C) in soils and sediments are needed to gauge the role of environment and time in the dynamics of this stable carbon form. The benzenecarboxylic acids (BnCA, with n = number of carboxylic groups) and naphthalene analogues (NnCA) released by thermally assisted hydrol...