Melanins and lipids in Lycoperdon perlatum fruit bodies

5 pages, 1 figure, 3 tables, 27 references.After sequential degradation with sodium persulphate and potassium permanganate, the characteristics of the dark pigments from the soil gasteromycete Lycoperdonperlatum were described. Several aromatic acids (phenolic and benzenecarboxylic) were detected by glc-ms of the degradation products, but the aliphatic content of these polymer fractions was predominant, containing a high proportion of protein and showing fatty acids similar to those previously found in the lipid fraction. An acid soluble fraction of melanin, of a highly aliphatic nature, was also present in Lycoperdon fruit bodies.Peer reviewe

La oxidación con perborato como método para el estudio de la composición de biopolímeros orgánicos y de las sustancias húmicas del suelo

Comunicación presentada a la citada Bienal, celebrada del 16-20 de septiembre, 1985, en Barcelona, España.Se propone un método degradativo aplicable a las sustancias de tipo húmico basado en la des polimerización progresiva de la muestra por acción del peróxido de hidrógeno generado por un exceso de NaB02.H202 que reacciona simultáneamente con los propios grupos carboxilos del sustrato.Peer reviewe

Estudio de la naturaleza de las fracciones alteradas de lignina mediante degradación secuencial de la húmina heredada de los suelos

Comunicación presentada a la citada Bienal, celebrada del 16-20 de septiembre, 1985, en Barcelona, España.Es bien conocido que la elevada resistencia a la biodegradación de las ligninas se traduce en un largo periodo de residencia media incluso en los ecosistemas biológicamente más activos. Mientras que una parte de la lignina se convierte en compuestos de bajo peso molecular, también se acumula una fracción alterada que difiere del material de partida por la pérdida de grupos metoxilo e incorporación de grupos oxigenados y nitrogenados. En el caso del humus de los suelos, dichos procesos se conocen como de humificación directa, y conducen a la formación de la húmina heredada.Peer reviewe

The behaviour of diborane-reduced fulvic acids in flash pyrolysis

7 pages, 3 figures, 1 table, 25 references.-- Publicado en el capítulo: Session 1: Isolation, Fractionation, and Characterization.-- Humic Substances in the Aquatic and Terrestrial Environment, Proceedings of an International Symposium, celebrado del 21-23, agosto, 1989 en Linköping, Suecia.-- Este volumen 33, referido en la Citación, consta de 514 páginas, 150 figuras y 57 tablas.It is suggested that the striking structural changes introduced in humic substances by reduction with diborane may be useful in studying the role of carboxyl groups in the behaviour of these substances in flash pyrolysis. In the preliminary results shown in this communication, pyrograms of two fulvic acids of different origins and the corresponding diborane reduced substances are compared. It was found that the diborane reduction was responsible for both qualitative and quantitative changes in the pyrolytic patterns of the fulvic acids. These patterns feflect the changes in the reactivity and structural stability of the fulvic materials caused by the disappearance of the carboxyl groups.Peer reviewe

Fulvic acids from particulate matter of a water-logged peatland

6 pages, 3 figures, 2 tables, 29 references.The presence of aggregates of humic substances (HS) with inorganic adsorbates in a lagoon located in Huelva (south Spain) is reported. The chemical nature of the fulvic acid (FA) fraction, extracted from the natural aggregate by treatment with chelating resins, has been investigated by physical and chemical methods. The results suggest that these FA are similar to FA from other aquatic environments. As revealed by FT-IR and NMR spectroscopies and mild oxidation with potassium persulfate, the FA contain predominantly in their structure polysaccharides and components derived from lignin.Peer Reviewe

Pyrolysis-GC-MS analysis of the formation and degradation stages of charred residues from lignocellulosic biomass

The structural transformations undergone by lignocellulosic biomass (freeze-dried rye grass, Lolium rigidum) subjected to progressive isothermal heating (burning at 350°C under oxidizing conditions for 30, 45, 60, 75, and 90 s) have been monitored by Curie-point pyrolysis-gas chromatographymass spectrometry (Py-GC-MS). The pyrograms suggest that even charred residues after severe heating (carbon loss ca. 50%) still contain substantial concentrations of some resistant plant structural components. Several trends were observed when monitoring the relative concentrations of the different groups of pyrolysis compounds released during successive charring stages: (i) the tetrapyrrole moiety of chlorophylls is rapidly destroyed as indicated by the decreasing yields of pyrroles and pyrrolines, whereas the phytol backbone is comparatively more resistant, leading to phytadienes after dehydration and reduction; (ii) the increasing yields of imidazoles from progressively heated samples (maximum at 45 s stage) suggest accumulation of newly formed nitrogen-containing compounds that may survive natural fires; (iii) the lignin backbone shows a relative resistance, the yields of aromatic products pointing to progressive demethoxylation; and, (iv) a selective accumulation of recalcitrant alkyl material occurred, which is interpreted as the result of thermal condensation of hydrocarbons and fatty acids into macromolecular materials in the charred residue. In terms of the intensity of the isothermal heating, the yields of the different classes of alkyl compounds follow the order phytadienes < fatty acids < alkanes < wax esters < sterols.Peer Reviewe

Comparison of humic and fulvic acids from different soils by pyrolysis-mass spectrometry

7 pages, 3 figures, 11 references.[EN]: Several recent publications showed the usefulness of pyrolysis mass spectrometry for the characterization of the organic matter of total soil samples and of soil organic matter fractions. Soil humic and fulvic acidS were pyrolyzed by the Curiepoint pyrolysis technique and were analyzed with a fast scanning low voltage electron impact mass spectrometer. Humic acids from different soil types and geographical distribution were characterized by series of homologous compounds, which were derived from protein, polysaccharides, alkanes, and lignin phenols. Fulvic acids showed great similarities and few variations in the relative abundance of pyrolysis products, with major peaks arising from polysaccharides: Aromatics and phenols were scanty or hardly detected.[ES]: Publicaciones recientes han mostrado la utilidad de la pirólisis-espectrometría de masas para la caracterización de la materia orgánica del suelo y sus fracciones. Ácidos húmicos y fúlvicos fueron pirolizados usando la técnica de la pirólisis por punto de Curie y analizados con un espectrómetro de masas de impacto electrónico a bajo voltaje. Los ácidos húmicos de diferentes tipos de suelos y orígenes geográficos se caracterizaron por series de compuestos homólogos, encontrándose derivados de proteínas, polisacáridos, alcanos y fenoles procedentes de la lignina. Los ácidos fúlvicos se mostraron muy similares y con pocas variaciones en la abundancia relativa de productos de pirólisis, hallándose que los picos mayores procedían de la pirólisis, de polisacáridos, mientras que, por el contrario, los compuestos aromáticos y fenoles fueron escasos y difícilmente detectables.This work was made possible by research grants from the Deutsche Forschungsgemeinschaft, the Dutcb Foundation Research on Matter (F.O.M) und the Dutch Ministry of Health and Environmental Hygiene.Peer reviewe

Biorefineries: Achievements and challenges for a bio-based economy

Funding This work was supported by a project (FQM-176) financed by the Junta de Andalucía. FM-M, acknowledges the support from the Global Challenges Research Fund from Swansea University, and from the Royal Society of Chemistry Enablement Grant (E21-7051491439).Climate change, socioeconomical pressures, and new policy and legislation are driving a decarbonization process across industries, with a critical shift from a fossil-based economy toward a biomass-based one. This new paradigm implies not only a gradual phasing out of fossil fuels as a source of energy but also a move away from crude oil as a source of platform chemicals, polymers, drugs, solvents and many other critical materials, and consumer goods that are ubiquitous in our everyday life. If we are to achieve the United Nations’ Sustainable Development Goals, crude oil must be substituted by renewable sources, and in this evolution, biorefineries arise as the critical alternative to traditional refineries for producing fuels, chemical building blocks, and materials out of non-edible biomass and biomass waste. State-of-the-art biorefineries already produce cost-competitive chemicals and materials, but other products remain challenging from the economic point of view, or their scaled-up production processes are still not sufficiently developed. In particular, lignin’s depolymerization is a required milestone for the success of integrated biorefineries, and better catalysts and processes must be improved to prepare bio-based aromatic simple molecules. This review summarizes current challenges in biorefinery systems, while it suggests possible directions and goals for sustainable development in the years to come.Project (FQM-176) financed by the Junta de AndalucíaGlobal Challenges Research Fund from Swansea UniversityRoyal Society of Chemistry Enablement Grant (E21-7051491439

Understanding the impact of line-of-sight in the ergodic spectral efficiency of cellular networks

In this paper we investigate the impact of lineof-sight (LoS) condition in the ergodic spectral efficiency of cellular networks. To achieve this goal, we have considered the kappa-mu shadowed model, which is a general model that provides an excellent fit to a wide set of propagation conditions. To overcome the mathematical complexity of the analysis, we have split the analysis between large and small-scale effects. Building on the proposed framework, we study a number of scenarios that range from heavily-fluctuating LoS to deterministic-LoS. Finally, we shed light on the interplay between fading severity and spectral efficiency by means of the amount of fading.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Model-based run-to-run optimization for process development

Research and development of new processes is a fundamental part of any innovative industry. For process engineers, finding optimal operating conditions for new processes from the early stages is a main issue, since it improves economic viability, helps others areas of R&D by avoiding product bottlenecks and shortens the time-to-market period. Model-based optimization strategies are helpful in doing so, but imperfect models with parametric or structural errors can lead to suboptimal operating conditions. In this work, a methodology that uses probabilistic tendency models that are constantly updated through experimental feedback is proposed in order to rapidly and efficiently find improved operating conditions. Characterization of the uncertainty is used to make safe predictions even with scarce data, which is typical in this early stage of process development. The methodology is tested with an example from the traditional innovative pharmaceutical industry.Fil: Luna, Martín Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Martínez, Ernesto Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; Argentin