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The majority of organic P (Porg) in soil is considered to be part of soil organic matter (SOM) associations, but its chemical nature is largely ‘unresolved’. In this study, we investigated the Porg composition in different SOM fractions of a Gleysol soil using the Humeomics sequential chemical fractionation (SCF) procedure combined with nuclear magnetic resonance (NMR) spectroscopy. In summary, SCF procedure with subsequent NaOH-EDTA extraction of the soil residue extracted a total of 1769 mg P/kgsoil compared to 1682 mg P/kgsoil of a single-step NaOH-EDTA extraction. Approximately 38 % of the extracted Porg was present in the form of the unresolved Porg pool, which was represented by one or two underlying broad signals in the phosphomonoester region of solution 31P NMR spectra. The SCF revealed that phosphomonoesters were recovered in each fraction: 47 % of the unresolved phosphomonoesters were associated with the SOM fraction released by breaking ester bonds (40 %) and ether bonds (7 %), whereas about 30 % of this unresolved Porg pool appeared in the SOM fraction closely associated with the soil mineral phase. Furthermore, the extractability of inositol phosphates (IP) was increased from 312 mg P/kgsoil to 534 mg P/kgsoil (factor 1.7) using the SCF procedure compared to a single-step NaOH-EDTA extraction. Previous studies have reported the presence of IP in molecular size fractions greater than 10 kDa. Our findings on the removal of IP with the fractionation of the SOM could explain the presence of IP in these large associations. We demonstrate that major pools of Porg are closely associated with SOM structures, comprising a diverse array of chemical species and bonding types. These results forward our understanding of Porg stabilisation, P transformation, and P cycling in terrestrial ecosystems towards an association point of view., Geoderma, 429, ISSN:0016-7061, ISSN:1872-6259

The growing use of electric vehicles is requiring the implementation of power electronics applications with ever faster devices, such as silicon carbide (SiC) MOSFET, to reduce switching power losses and reach higher power density, with the final objective of improving performance and lowering the system cost. A side effect of such faster switching devices is the generation of high-frequency harmonics with significant energy, so their impact must be evaluated in terms of conducted and radiated electromagnetic interference (EMI). The optimal design of PCBs and filters for facing electromagnetic compatibility issues requires properly estimating the EMI level of different design solutions. Analysis of the current state of the art reveals that previous approaches can not effectively support a design focusing on a reduction in radiated EMI. To surpass these limits, the paper defines an electromagnetic simulation flow aimed at evaluating the radiative fields in the case of an integrated power electronics module operating in automotive applications and featuring fast SiC power devices. Then, the proposed simulation was applied to an LLC resonant converter featuring an STMicroelectronics SiC-based ACEPACK module. The work also highlights that future research efforts must concentrate on finding the best compromise between computational effort and estimation accuracy.

Since late December 2019, severe acute respiratory syndrome coronavirus 2 has spread across the world, which resulted in the World Health Organization declaring a global pandemic. Coronavirus disease 2019 (COVID-19) presents a highly variable spectrum with regard to the severity of illness. Most infected individuals exhibit a mild to moderate illness (81%); however, 14% have a serious disease and 5% develop severe acute respiratory distress syndrome (ARDS), requiring intensive care support. The mortality rate of COVID-19 continues to rise across the world. Data regarding predictors of mortality in patients with COVID 19 are still scarce but are being actively investigated. The present multicenter retrospective observational study provides a complete description of the demographic and clinical characteristics, comorbidities and laboratory abnormalities in a population of 421 hospitalized patients recruited across eight infectious disease units in Southern Italy (Sicily) with the aim of identifying the baseline characteristics predisposing COVID-19 patients to critical illness or death. In this study, older age, pre-existing comorbidities and certain changes in laboratory markers (such as neutrophilia, lymphocytopenia and increased C-reactive protein levels) at the time of admission were associated with a higher risk of mortality. Male sex, on the other hand, was not significantly associated with increased risk of mortality. Symptoms such as fatigue, older age, a number of co-pathologies and use of continuous positive airway pressure were the most significant contributors in the estimation of clinical prognosis. Further research is required to better characterize the epidemiological features of COVID-19, to understand the related predictors of death and to develop new effective therapeutic strategies.

Background and aims Biostimulants of natural origin represent a growing ecological strategy to increase crops productivity, especially when applied in combination with microbial bioeffectors. We studied the effect of biostimulants such as Potassium Humates (KH) from Leonardite and Compost Tea (CT) from green compost on both productivity and nutritional status of lettuce plants, as well as on the primary and secondary metabolism of treated plants, when amended either alone or in combination with a commercial microbial inoculum (M+), mainly based on arbuscular mycorrhizal fungi (Micosat TabPlus). Results The biomass production as well as the uptake of both macro- and micronutrients by lettuce plants significantly increased when amended by the mixture of both humic materials (MIX) combined with the microbial inoculum. Similarly, the synergic MIX_M+ treatment significantly affected both the primary and secondary metabolism of lettuce more than their individual applications, by increasing, respectively, the biosynthesis of essential amino acids and carbohydrates, and that of antioxidant polyphenolic compounds, such as hydroxycinnamic acids, flavonols and coumarins. Conclusions Our findings suggest that a calibrated mixture of humic bioactive molecules in combination with microbial consortia represents a potential tool to improve crop productivity and its nutritional and metabolic status.

Made available in DSpace on 2021-06-25T10:55:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-02-15 Hydrochar is a carbon-based material that can be used as soil amendment. Since the physical-chemical properties of hydrochar are mainly assigned to process parameters, we aimed at evaluating the organic fraction of different hydrochars through 13C-NMR and off-line TMAH-GC/MS. Four hydrochars produced with sugarcane bagasse, vinasse and sulfuric or phosphoric acids were analyzed to elucidate the main molecular features. Germination and initial growth of maize seedlings were assessed using hydrochar water-soluble fraction to evaluate their potential use as growth promoters. The hydrochars prepared with phosphoric acid showed larger amounts of bioavailable lignin-derived structures. Although no differences were shown about the percentage of maize seeds germination, the hydrochar produced with phosphoric acid promoted a better seedling growth. For this sample, the greatest relative percentage of benzene derivatives and phenolic compounds were associated to hormone-like effects, responsible for stimulating shoot and root elongation. The reactions parameters proved to be determinant for the organic composition of hydrochar, exerting a strict influence on molecular features and plant growth response. Laboratório de Estudos em Ciências Ambientais Instituto de Biociências Universidade Estadual Paulista (Unesp) Letras e Ciências Exatas, Campus São José do Rio PretoRua Cristovão Colombo 2265 Interdepartmental Research Centre on Nuclear Magnetic Resonance (NMR) for the Environment Agro-Food and New Materials (CERMANU) Università degli Studi di Napoli Federico II, Via Università 100 Laboratório de Materiais Funcionais Avançados (LaMFA) Universidade Federal do Ceará Laboratório de Estudos em Ciências Ambientais Instituto de Biociências Universidade Estadual Paulista (Unesp) Letras e Ciências Exatas, Campus São José do Rio PretoRua Cristovão Colombo 2265

A Humeomic fractionation revealed the humus molecular composition of two uncropped calcareous soils of Northern France and differentiated the soils Humeome by extracting humic components first unbound to the organo-mineral matrix and then liberated from their progressively stronger intermolecular and intramolecular ester and ether linkages. We separated organo- (ORG1-3) and water-soluble (AQU2 and AQU4) fractions, a final extractable fraction (RESOM) and soil residues. Organo-soluble fractions were studied by GC coupled with high-resolution mass spectrometry (GC/qTOF-MS), all fractions underwent mono- and two-dimensional liquid-state NMR (except for the iron-rich AQU4 fraction), while solid-state 13C-CPMAS-NMR spectroscopy analyzed soil residues. The Calcaric Leptosol (A) showed a larger mass extraction than the Calcaric Cambisol (B), and a greater cumulative C and N content in its Humeome. Both soils showed the greatest weight yield for AQU4 fraction, followed by ORG2, RESOM, ORG1, AQU2, and ORG3. ORG2 was the most differentiating fraction between the two soils for both compound concentration and diversity, showing a larger C content for soil A than for soil B and a different distribution in aromatic compounds, fatty acids, and dicarboxylic acids. No significant differences between soils were found for ORG 3, suggesting similar processes of OM stabilization for its recalcitrant components, mostly hydrophobic esters of alkanoic, hydroxy, and aromatic acids with linear alkanols. We confirmed that Humeomic fractionation coupled to advanced analytical instrumentations enabled a detailed molecular characterization of the soil Humeome and differentiated between the two calcareous grassland soils and the other soils previously subjected to Humeomics.

Companies working on semiconductors must currently assure the customers of not only the performance of the semiconductor device per se, but also its performance when it is implemented in a real board, therefore including the role of parasitic effects. It is therefore very important to evaluate, especially during the design phase, not only the single device, but the complete board and their mutual interactions. This consideration opens a new area of investigation in the field of electronic systems engineering. In the current literature, the problem of a software evaluation of parasitic dynamics and electromagnetic effects on printed boards is addressed from the point of view of researchers. Moreover, it is fundamental to have a complete view of the various tools that could be usefully adopted from the perspective of manufacturers. This is the main motivation of this technical note, which performs a comparative analysis of the most prominent software tools for printed circuit boards’ (PCBs) simulation. The main features, the key aspects, and the limitations of the software packages are analyzed in terms of the industrial design of power electronics devices, in order to ensure efficiency and fastness in the semiconductor market.

The coronavirus disease 2019 (COVID-19) has severely stressed the sanitary systems of all countries in the world. One of the main issues that physicians are called to tackle is represented by the monitoring of pauci-symptomatic COVID-19 patients at home and, generally speaking, everyone the access to the hospital might or should be severely reduced. Indeed, the early detection of interstitial pneumonia is particularly relevant for the survival of these patients. Recent studies on rheumatoid arthritis and interstitial lung diseases have shown that pathological pulmonary sounds can be automatically detected by suitably developed algorithms. The scope of this preliminary work consists of proving that the pathological lung sounds evidenced in patients affected by COVID-19 pneumonia can be automatically detected as well by the same class of algorithms. In particular the software VECTOR, suitably devised for interstitial lung diseases, has been employed to process the lung sounds of 28 patient recorded in the emergency room at the university hospital of Modena (Italy) during December 2020. The performance of VECTOR has been compared with diagnostic techniques based on imaging, namely lung ultrasound, chest X-ray and high resolution computed tomography, which have been assumed as ground truth. The results have evidenced a surprising overall diagnostic accuracy of 75% even if the staff of the emergency room has not been suitably trained for lung auscultation and the parameters of the software have not been optimized to detect interstitial pneumonia. These results pave the way to a new approach for monitoring the pulmonary implication in pauci-symptomatic COVID-19 patients.

Background An insight into the molecular composition of ombrotrophic peats of different geographical origin and collected at different depths was achieved by the humeomics method. The humeomic fractionation allowed the separation of molecular components in either organic solvents or water on the basis of their progressive binding strength to the humic matrix. The solubilized matter in fractions was analyzed by gas chromatography–mass spectrometry (GC–MS) or by proton nuclear magnetic resonance (1H NMR) spectroscopy, while the residues depleted of the extracted material were observed by 13C cross-polarization magic-angle-spinning nuclear magnetic resonance (13C-CPMAS-NMR) spectroscopy. Results The analytical characterization of fractions and residues differentiated peats not only on the basis of the different classes of extracted molecules, but also on their binding strength to the complex peat matrix. Aromatic, lipidic, and sugar compounds were the most representative molecular classes extracted in the humeomic fractions and their abundance varied with depth. The distribution and abundance of extracted compounds provided an indication of the extent of organic matter accumulation in peat. The NMR spectra of solid residues supported the interpretation of the characteristics of the various extracts. Conclusions Our findings proved that the humeomic approach allows to provide important information on both the molecular composition of peats and its variation with depth.

High resolution mass spectrometry (HRMS) can resolve thousands of compounds in complex mixtures such as natural organic matter. However, HRMS is seldom sufficient to fully resolve the molecular heterogeneity of Humus in the soil matrix, especially if no preliminary simplification of Humus complexity is applied and if a single ionization technique is used. Here we show that HRMS, when applied with both photoionization (APPI) and electrospray ionization (ESI) and combined with the extensive molecular simplification provided by a humeomic fractionation, significantly increases identification of the molecular composition of soil Humus. Different sequential extractions separate the soil Humeome in three organosoluble fractions (ORG1-3) and two hydrosoluble fractions (AQU2 and RESOM), which showed distinct molecular characteristics. The ORG fractions were particularly homogeneous and rich in alkyl compounds including unsaturated hydrocarbons and lipid compounds found mainly in ORG 1 and ORG 3, but also aromatic compounds comprising lignin-like molecules and condensed structures mainly detected in ORG2. The AQU2 fractions revealed greater complexity and heterogeneity due to the simultaneous detection of sugars, amino sugars, tannins and N-containing compounds not detectable in appreciable concentrations in other fractions. The most recalcitrant RESOM fraction contained highly reduced molecules and condensed structures. The combined use of APPI and ESI showed a marked selectivity in the detection of chemically different molecules separated in each fraction, thereby enhancing their molecular characterization. Specifically, APPI tended to ionize less oxidized and N-containing molecules, and compounds with high concentrations of unsaturation or aromatics, while ESI was more prone to detect highly oxidized compounds consisting of large O/C ratios. Our findings indicate that the combination of a soil Humeome fractionation with a detailed high resolution characterization of differently ionized molecules in the separated fractions enables a far deeper understanding of the molecular composition of soil Humus and the comprehension of its environmental reactivity.

Plant growth-promoting bacteria of the genus Bacillus are known to solubilize phosphates and enhance plant growth in many plant species. We explored the effects of the inoculation with a commercial isolate Bacillus amyloliquefaciens on the growth and metabolic processes of maize plants in pot soils treated with triple superphosphate, rock phosphate, and either cow- or horse-manure composts, as P-fertilizers. The metabolic profiles of maize leaves in the different treatments were determined by both Gas Chromatography–Mass Spectrometry and Nuclear Magnetic Resonance spectroscopy. Principle Components Analysis (PCA) based on data matrix from both techniques revealed a relationship between treatments and specific plant metabolites. Inoculated plants showed larger P and N contents and a more differentiated metabolome when treated with the two composts than with inorganic fertilizers. B. amyloliquefaciens in combination with composts significantly increased glucose, fructose, alanine and GABA metabolites in maize leaves, thus suggesting an improved photosynthetic activity due to enhanced P and N uptake. Both composts sustained plant growth and the phosphate solubilizing activity of B. amyloliquefaciens, while differences in P and N contents in plant leaves were attributed to the different content in compost of lignin residues and alkyl moieties, and consequent impact on microbial growth. The combination of B. amyloliquefaciens inoculation with composted organic P-fertilizers rich in available metabolic carbon appears as an efficient alternative to mineral fertilizers to enhance nutrients uptake and foster growth mechanisms in maize plants.

To understand how climate change impacts soil fertility and ecosystem functioning, it is necessary to explore how different pools of soil organic matter (SOM) at aggregate scale are functionally affected in their molecular composition. Here, we collected rhizospheric soil at rice harvest from a paddy field in which a simulated climate change experiment was conducted for 6 years, including CO2 enrichment up to 500 μmol mol−1 (CE), air warming by 2 °C (WA), combination of CO2 enrichment and air warming (CW), and the ambient environment as control. The soil samples were separated in three aggregate fractions (macroaggregates, 2000-250 μm; microaggregates, 250-53 μm; clay & silt

It is not yet clear whether the carbon released from biochar in the soil solution stimulates biological activities. Soluble fractions (AQU) from wheat and maize biochars, whose molecular content was thoroughly characterized by FTIR, (13)C and (1)H NMR, and high-resolution ESI-IT-TOF-MS, were separated in dilute acidic solution to simulate soil rhizospheric conditions and their effects evaluated on maize seeds germination activity. Elongation of maize-seeds coleoptile was significantly promoted by maize biochar AQU, whereas it was inhibited by wheat biochar AQU. Both AQU fractions contained relatively small heterocyclic nitrogen compounds, whose structures were accounted by their spectroscopic properties. Point-of-Zero-Charge (PZC) values and van Krevelen plots of identified masses of soluble components suggested that the dissolved carbon from maize biochar behaved as humic-like supramolecular material capable to adhere to seedlings and deliver bioactive molecules. These findings contribute to understand the biostimulation potential of biochars from crop biomasses when applied in agricultural production.

The molecular composition of soil organic matter (SOM) of two calcareous soils highly rich in carbonates was assessed before and after decarbonation by acid washing with HCl through 13C-CPMAS-NMR spectroscopy and off-line thermochemolysis coupled with gas chromatography and mass spectrometry (THM-GC-MS). The acidic treatment promoted a considerable concentration of organic matter in both soils, thus improving the identification of molecules otherwise not easily detectable. Decarbonation induced only a slight loss of soil organic carbon (SOC), corresponding to 1.4 and 2.7% for A and B soils respectively. The acidic treatment also led to an increase in the organic carbon/total nitrogen (OC/N) ratio in soil A, while an opposite variation was found for the second soil. Moreover, variations in the concentration and molecular distribution of specific compound classes present in SOM were caused by the acid washing of soils. As confirmed by both 13C-CPMAS-NMR and thermochemolysis results, the molecules most susceptible to the acid treatment were the carbohydrates, lignin monomers (G14 and G15), fatty acids (C18 saturated and unsaturated), fatty acids of microbial origin (C15, C17, and C19), hydroxy acids (C16, C18), and dioic acids (C18) which represent the components weakly bound to the organic matrix. Our findings not only showed the efficacy of the decarbonation treatment of calcareous soils with 3 N HCl, but also indicated how the acidic washing can improve the differentiation of soils on the basis of SOM molecular characteristics.

The ability of Trichoderma harzianum (strain OMG-08) as plant growth promoting fungus (PGPF), was tested on Zea mays plants grown in soil pots added with different inorganic (triple superphosphate and rock phosphate) and organic (cow and horse manure composts) P fertilizers. The effect of treatments was evaluated by following the variations of plants dry biomass and nutrient content, as well as the metabolic changes in plant leaves by both GC-MS and NMR spectroscopy. A synergic effect was observed in treatments with both composts and fungus inoculation, in which not only plant growth and P uptake were enhanced, but also the expression of different metabolites related to an improved photosynthetic activity. Conversely, the combination of Trichoderma with inorganic fertilizers was less effective and even showed a reduction of plants shoot biomass and N content. The corresponding plant metabolome revealed metabolic compounds typical of biotic or abiotic stresses, which may be attributed to a reduced capacity of inorganic fertilizers to provide a sufficient P availability during plant growth. Our findings also indicate that the molecular composition of compost differentiated the Trichoderma activity in sustaining plant growth. The positive effects of the combined Trichoderma and compost treatment suggest that it may become an alternative to the phosphorus mineral fertilization.

Soil organic matter (SOM) or humus is essential for the agricultural and environmental functionality of soils. Humus comprises small-size heterogeneous organic molecules arranged in complex meta-stable suprastructures, whose composition can be greatly affected by land management. Here, we report the molecular dynamics of the fractions extracted from an agricultural soil cropped with wheat after one and three years of tillage. The total molecular components, named Humeome, of soil under wheat found in both hydrosoluble and organosoluble fractions isolated by the Humeomic procedure, as determined by GC–MS and high-resolution Orbitrap LC–MS, were compared to the Humeome characterized in the same soil when cropped with maize. While the three-years tillage did not vary the total soil organic carbon under both wheat and maize, the carbon recovered for the sum of Humeomic fractions isolated from soil was significantly larger for maize than for wheat, thus suggesting a general destabilization of SOM under wheat cropping. Moreover, the soil Humeome under wheat resulted more hydrophilic than under maize. While fatty acids and carbohydrates were periodically replenished by crop residues, nitrogen-containing molecules, such as amides and heterocyclic nitrogen, and iron-bound molecular systems were the SOM components mostly reduced under wheat. The losses of these compound classes from the soil Humeome was possibly attributed to the exudation differences between wheat and maize cropping. These results reveal that the molecular dynamics and stability of SOM molecular components can be controlled by crops even in a short term.

Background and aims: The use of composted agricultural wastes as source of biostimulant compounds provides an added value to the recycling of biomasses. This study aims to expand the knowledge on the relationship between molecular composition and bioactivity of the Humeome extracted from green composts. Methods: Humic acids (HA) were isolated from the following green composts: 1. artichoke (HA-CYN), 2. artichoke/fennel (HA-CYNF), 3. tomato (HA-TOM), 4. cauliflower (HA-CAV). The compost-extracted Humeome was characterized by solid- and liquid-state Nuclear Magnetic Resonance (NMR) Spectroscopy, Infrared Spectrometry, pyrolysis-gas chromatography/mass spectrometry (Pyr-GC/MS), elemental and thermal analyses (TGA, DSC), and the effects on maize (Zea mays L.) seedling growth (roots and shoots) and leaves chlorophyll content, investigated at three different concentration rates (25, 50 and 100 mg L−1 C). Results: All Humeomes from green composts generally favored plant growth, with HA-CYN and HA-CAV being active at small concentrations, while HA-TOM and HA-CYNF at greater application rates. The response of HA-CYN and HA-CAV was attributed to their large hydrophobicity that may favor adhesion to roots surfaces and concomitant release of bioactive molecules, whereas the toxicity of phenolic moieties in HA-TOM and HA-CYNF could only be mitigated by tighter intermolecular aggregation at greater concentrations. Conclusion: Bioactivity of Humeomes from green composts appeared to be related to their composition and consequent conformational structure in solution, whose flexibility determines the potential release of bioactive molecules that directly or indirectly influence plants development.

The importance of soil humus carbon in the ecological and environmental domains can be hardly overestimated. The complex and heterogeneous chemical nature of the soil Humeome has for a long time baffled the development of man-made technologies for the control of soil carbon. A new paradigm was introduced in the early years of the millennium that viewed soil humus as a supramolecular association of small molecules derived from the abiotic and biotic degradation of dead cells in soil. This chapter reports on the recent advances that established a general consensus around this new chemical understanding of soil humus. Based on this new paradigm, a sequential chemical fractionation of the soil Humeome was recently introduced, by which homogeneous fractions are progressively obtained without deliberately breaking carbon-carbon bonds in humic molecules and are then subjected to structural determination by advanced NMR spectroscopy and mass-spectrometry. This Humeomics technique promises to finally allow the molecular mapping of soil humus in different soil types and explain the effects of different soil-management practices on soil carbon dynamics. The supramolecular nature of the soil Humeome and its molecular unraveling by Humeomics have also contributed to explain its recalcitrance in soil and the so-far vague concept of humification. The latter should be intended as the progressive accumulation of hydrophobic molecular components, which are no longer biotically accessible because they are rapidly partitioned from liquid to the solid soil phases due to thermodynamic reasons. The new awareness on the composition and conformational arrangement of the soil Humeome has prompted the application of an in situ photo-oxidative technique under a biomimetic catalysis that enables the oligomerization of humic molecules, thereby not only improving soil structural stability but also sequestering carbon in soil to an extent never matched by any other technique aimed to stabilize carbon in soil. It is expected that the innovative perspectives on the soil Humeome highlighted here may serve to enlarge the potentials of sustainable agriculture and develop new environmental technologies.

Integrated power electronics modules (IPEMs) represent an innovative typology of power electronics assemblies able to guarantee several advantages such as increasing of power density, better management of the thermal flows, and a significant reduction of the package sizes. Their characteristics make them suitable for applications like motor drives or power conditioning. IPEM usage in emerging fields like hybrid automotive traction and electric generation from renewable energy sources is continuously increasing. In this paper, we describe the implementation of a devised flow to generate the layer-based electrothermal PSpice model of an IPEM and the simulation flow of the model. The proposed modeling methodology allows reducing an electrothermal multidomain problem to an electrical single one. The general PSpice-like nature of the proposed model makes it suitable for a wide range of simulation frameworks where the integration of heterogeneous multiphysics models could be a difficult task. The outlining of both electrical and thermal PSpice layers is discussed, and the implementation into the final model, by the assistance of custom electronic-design-automation flow, is presented. Moreover, we describe the validation procedure of the proposed approach, and the results are compared with the ones obtained by a commercial finite-element-based package used as a benchmark. Two simulation approaches related to specific conversion systems, and related issues, are presented and discussed.

Water-soluble humic-like lignins from energy crops had been previously shown to significantly improve plant development due to their chemical composition and supramolecular arrangement. Here, humic-like lignins isolated from Giant Reed were tested in several bioassays to verify whether the biostimulation was due to a hormone-mimic (auxin- and gibberellin-like) activity. The water-soluble lignins were applied on tomato seeds harboured with the auxin reporter DR5::GUS (β-glucuronidase), to visualize the auxin responses in roots. Moreover, auxin- or gibberellin (GA)-mimetic activities were assessed by the Audus test on watercress and chicory seeds, respectively, with increasing concentrations of water-soluble lignin. The latter showed a significant GA-like effect, whereas it did not produce auxin-like activity at any assayed concentration. The water-soluble lignins may either directly function as GA on plant and seed development or positively perturb GA-related hormonal balances, thereby influencing GA-mediated physiological mechanisms. These findings suggest that humic-like residual lignins from energy crops may be useful in intensified sustainable agriculture as seed germination enhancers and biostimulants of plant growth.

Four water extractable organic matter (WEOM) were obtained from composts made out of residues of: 1. artichoke (C-CYN), 2. artichoke/fennel (C-CYNF), 3. tomato/woodchips (C-TOM), 4. Municipal solid waste (C-MSW), and their bioactivity was tested for maize seed germination and maize seedling growth. The molecular properties of both original composts and their WEOM were characterized by spectroscopic ((13)C-CPMAS- and (1)H NMR, FTIR-ATR), thermochemolysis-GC/MS, and thermal methods (TGA, DSC). While all WEOM had significant effects on plant growth, CYN-WEOM was the only material that concomitantly increased germination rate and primary and lateral root length of maize seedlings. The lignin-rich WEOM from green composts were generally more effective than those obtained from equally hydrophobic, but mainly alkyl-rich municipal organic wastes. A flexible conformational structure, due to the balanced content of aromatic compounds and carbohydrates, appeared to facilitate the release of bioactive molecules from WEOM suprastructures and stimulate plant growth.

A Humeomics sequential chemical fractionation coupled to advanced analytical identification was applied directly to soil for the first time. Humeomics extracted ~235% more soil organic carbon (SOC) than by the total alkaline extraction traditionally employed to solubilise soil humic molecules (soil Humeome). Seven fractions of either hydro- or organo-soluble components and a final unextractable humic residue were separated from soil. These materials enabled an unprecedented structural identification of solubilised heterogeneous humic molecules by combining NMR, GC-MS, and ESI-Orbitrap-MS. Identified molecules and their relative abundance were used to build up structure-based van Krevelen plots to show the specific contribution of each fraction to SOC. The stepwise isolation of mostly hydrophobic and unsaturated molecules of progressive structural complexity suggests that humic suprastructures in soil are arranged in multi-molecular layers. These comprised molecules either hydrophobically adsorbed on soil aluminosilicate surfaces in less stable fractions, or covalently bound in amorphous organo-iron complexes in more recalcitrant fractions. Moreover, most lipid molecules of the soil Humeome appeared to derive from plant polyesters rather than bacterial metabolism. An advanced understanding of soil humic molecular composition by Humeomics may enable control of the bio-organic dynamics and reactivity in soil.

While crop productivity and carbon flux/partitioning in agroecosystem have been widely addressed, potential changes in organic matter composition through root deposition are still unknown under climate change. In this study, root exudates of rice and rhizospheric topsoil were collected in a paddy field under 6 years of simulated climate changes respective of CO2 enrichment, canopy air warming, and their combination as compared to the control. The molecular composition of root exudates was analyzed with liquid chromatography/mass spectrometry (LC/MS) while soil organic matter (SOM) was analyzed with pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), along with a phospholipid fatty acid analysis (PLFA) for characterizing soil microbial community. Compared to control, root exudation under elevated CO2 was enhanced but the exudate composition remained unchanged. On the other hand, root exudation rate under warming was unaffected, but the exudate composition was changed. Relative abundance of phenolic compounds in root exudates under warming, was decreased by 26% but that of amino acids was increased by 53%. However, neither root exudation nor the exudate composition was altered under combined CO2 and temperature elevation. Furthermore, increases in abundance of heterocyclic nitrogen compounds, phenolic acids and phenols (by 37%, 65%, and 26%, respectively) in SOM were relevant to the increase in bacterial/fungal (B/F) ratio under elevated CO2. This accumulation was possibly attributed to preferential utilization of the increased root exudates by bacteria. However, the overall reduction of some highly hydrophobic SOM compounds (fatty acids, phenols, and phenolic acids) by 14%, could be induced by accelerated decomposition in line with significant decrease in B/F ratio under warming. Indeed, the decreased relative abundance of phenolic compounds such as p-coumaric acid (by 49%) in root exudates lead to fungal increase, which accelerated SOM decomposition. Yet, the molecular composition of SOM was hardly changed under the combination of elevated CO2 and temperature. Overall, our findings suggested that in a rice paddy CO2 enrichment increased root exudation and B/F ratio, while air warming altered the root exudate composition and decreased B/F ratio, resulting in changes of SOM composition. These results indicate that root exudates are a key component for the regulation of SOM dynamics under climate change scenarios.

Methods devoted to electrothermal simulation are presented as a useful tool for both the analysis and characterization of behavior of power semiconductor devices standing alone, and/or coupled in integrated circuits or power modules. First of all the implementation of a devised flow to generate the layer-based electrothermal PSpice model of an IPEM (Integrated Power Electronics Module) and the simulation flow of the model is presented. The proposed methodology allows reducing an electrothermal multi-domain problem to a single electrical one. The general PSpice-like nature of the proposed model makes it suitable for a wide range of simulation frameworks and avoids the integration of heterogeneous multiphysics models. The outlining of both the electrical and thermal PSpice layers is discussed, and the implementation into the final model is presented. Besides, the validation procedure of the proposed approach is described and the results compared with the ones obtained by a commercial finite-element package used as a benchmark. Secondly, two main approaches to fast 3-D electrothermal simulation are proposed. The designed methods—automated interaction of Sentaurus Device and HSPICE based on the relaxation method and mixed-mode setup in Sentaurus Device, by Synopsys TCAD Sentaurus—are compared with standard device finite-element model simulation and a direct method with an equivalent thermal 3-D RC network. The proposed simulation methods have been developed for decreasing the simulation time for complex 3-D devices. A superjunction MOSFET and a DC–DC converter module under different operating conditions are used to perform the validation of the simulation and calibration of their parameters.

We applied humeomics to a soil unextractable humin fraction (HUM1) and its derived humin (HUM2) after removal of minerals by an HF/HCl treatment. Humeomics implies progressive separation and structural characterization of molecules released from complex humin matrices as (i) unbound, (ii) weakly ester-bound, (iii) strongly ester-bound, and (iv) ether-bound. Molecular characterization of fractions was achieved by GC-MS, thermochemolysis-GC-MS, and 13C-CPMAS-NMR. Both weight and chromatographic yields were higher for the clay-depleted HUM2 than those for HUM1, and this increased molecular detection in HUM2. Saturated and unsaturated alkanoic, α,ω-alkanedioic, hydroxyalkanoic acids, alkanols, and hydrocarbons were found in both HUM1 and HUM2. Abundant odd-C numbered n-alkanoic acids in unbound fractions indicated accumulation of free microbial metabolites, whereas plant-derived acids remained in fractions more tightly bound to the humin matrix. Unsaturated, n-alkanedioic, and hydroxyalkanoic acids were detected after hydrolysis of complex esters. The aromatic character in humin residues progressively increased with humeomics sequential steps, while alkyl and hydroxy-alkyl compounds were reduced. Humins contained similar components as a humic acid extracted from the same soil, implying that traditional humic pools differed in supramolecular arrangement rather than in molecular composition. The humeomic approach enables the determination of the molecular composition of humic matter and may improve knowledge of the structure-activity relations of organic matter in soil.

Integrated Power Electronics Modules (IPEMs) have been developed to relieve the converter manufacturers of the burden of several discrete power devices integration. With respect to generic assemblies, modern high-end IPEMs guarantee several advantages such as high power density, low profiles and an optimal management of the wasted heat. An available model able to reproduce both electrical and thermal behavior is helpful to save designers' time and to avoid the application failure due to overheating. In this paper, a layered-approach methodology aimed at generating an IPEM model featuring six IGBT devices connected in a three-phase bridge topology is described. The approach relies on a strategy that implies the definition of an electrical and thermal layer in a segregate way and has as main objective the generation of a full-PSpice model of the IPEM able to take into account both the electrical and thermal behavior. The layers are then linked together by an IGBT self-heating model. The thermal layer, which poses many difficulties for its implementation, is automatically synthetized by using a custom Electric Design Automation (EDA) flow developed within the context of this work. A series of comparison between FEM simulations and the final PSpice model demonstrates the validity of the proposed approach.

In recent years, power electronics solutions spread through fields ever less tied to a pure industrial context for embracing on-coming applications in consumer, automotive and renewable energy markets. In all those contexts several requirements drive engineers in implementing assemblies having increasingly strict constraints as high power density, optimal management of temperature, and a more and more compact and mechanically robust structure, so to guarantee a good degree of integration in the host system. In applications where the power to be managed is significant (tens to hundreds of kW), Integrated Power Electronics Modules (IPEMs) play a major role. These solutions, already extensively industrialized, well satisfy the above mentioned integration requirements, and allow the final customer to reduce power-management costs. In order to design an IPEM able to satisfy all the requirements it is necessary to have preliminary CAD models able to predict its behavior from several points of view. In this work, a layered modeling flow able to take into account both the electrical and thermal behavior is detailed. Moreover, a series of issues able to produce prospective mechanical stresses and related failure conditions are discussed.

In recent years, the development of electronic systems that make use of high-rate power circuitry is increasingly frequent also for markets going beyond the typical industrial sector. So, the implementation of efficient electronic modules aimed at converting power, in ambits such as renewable energy equipment or hybrid-electric vehicle motor drives, represents a new challenge for designers. Often, the amount of power to be managed is very significant and no rarely it exceeds tens of kW. In this context, new concepts for manufacturing power converters are emerging and Integrated Power Electronics Modules (IPEM) represent a solution which guarantees better performances. The design of applications exploiting IPEM concept requires multi-domains simulation models able to predict the thermal behaviour of the module according to its electrical performances. In this work, a new methodology aimed at automatizing the synthesis of PSpice-like models able to reproduce both electrical and thermal dynamics is discussed. The model, generated by starting with a series of data retrieved by FEM simulations, exploits a mapping between electrical and thermal quantities and allows reproducing the characteristics of the module in a pure PSpice simulation environment. After a description of the electro-thermal model and the related developed EDA synthesis environment, a series of simulation issues are discussed.

In this work, the implementation flow of an electro-thermal model of an Integrated Power Electronics Module is presented. The methodology is based on an innovative layered approach where the whole system is devised as composed by two distinct layers, an electrical and a thermal one, linked together through the active model of a discrete power MOSFET device. We describe an original methodology aimed at reducing an electro-thermal multi-domain problem to an electrical single-domain one thanks to a mapping between thermal and electrical quantities. The strong point of the proposed approach relies on the fact that layers, generated independently with the aid of FEM simulations, are then melted together in a spice-like macro model that could be used, by engineers, in a pure spice-like design environment without the aid of external mathematical solver engines. Finally, a series of simulation issues are discussed.