Decomposition Of Residues Research Articles

STUDY OF THE CELLULOLYTIC ACTIVITY OF A COLLECTION OF "FIELD" BACTERIAL CULTURES

Decomposition of organic substances is widespread in all types of soils and plays an important role in the carbon cycle. The decomposition of cellulose plays a special role, since cellulose is the most common polysaccharide in plant residues and can be used by new plants in the form of simpler compounds. At the same time, the rate of decomposition of plant residues in the soil takes a considerable time and largely depends on the type of soil and its microbial composition. The use of individual most active microorganisms in the composition of biological products can increase soil fertility, especially in those areas where the original composition of the microflora does not contribute to the active decomposition of plant residues. In this study, the cellulolytic activity of various strains of microorganisms isolated from the soil was studied and compared. The objects of the study were a collection of 56 strains. The study of cellulolytic activity was carried out on nutrient media containing a cellulose source using congo dye ed. The obtained results showed a different level of cellulolytic activity in the studied strains. In some cases, there was an increase in activity with a decrease in the number of bacterial cells. 18 of 56 strains demonstrated cellulose degradation only within the limits of bacterial colony growth. According to the results of the studies, 6 strains of microorganisms with the largest zone of cellulolytic activity, reaching a radius of 15 mm around the grown colony, were noted. Among the most active strains, only one was Gram-negative bacteria, while the rest were gram-positive microorganisms.

Decay of oil residues in the soil is enhanced by the presence of Spartina alterniflora, with no additional effect from microbiome manipulation

Recent work has suggested that the phytoremediation potential of S. alterniflora may be linked to a selection by the plant for oil-degrading microbial communities in the soil, in combination with enhanced delivery of oxygen and plant enzymes to the soil. In salt marshes, where the soil is saline and hypoxic, this relationship may be enhanced as plants in extreme environments have been found to be especially dependent on their microbiome for resilience to stress and to respond to toxins in the soil. Optimizing methods for restoration of oiled salt marshes would be especially meaningful in the Gulf of Mexico, where there is a persistently high threat of petroleum contamination. One favorable strategy for restoration of oiled sites might include planting S. alterniflora with a microbiome that has been pre-selected for an oiled environment. We examined this strategy with a two-year greenhouse experiment and found that planting S. alterniflora in an oiled environment enhances decomposition of oil residues without a clear negative impact on plant growth. Manipulation of the S. alterniflora microbiome through soil inoculation and through exposure to oil residues, elicited a detectable response of soil prokaryote communities to the presence of oil, while only demonstrating an analogous response in fungal communities in the plant roots and leaves. Yet, manipulation of the plant microbiome did not change plant morphology or relative decomposition of polycyclic aromatic hydrocarbons (PAHs) in the soil. Therefore, despite evident relationships between the plant, microbes, and oil, manipulation of the microbiome may not be a worthwhile addition to S. alterniflora phytoremediation strategies. Nevertheless, our work adds support for replanting S. alterniflora in oiled salt marshes as an effective strategy for reducing oil residues in salt marshes, in addition to the re-vegetation and erosion reduction benefits demonstrated by others.

Response of aquatic plant decomposition to invasive algal organic matter mediated by the co-metabolism effect in eutrophic lakes

The decomposition of aquatic plant residues changes by the invasive algal organic matter in eutrophic lakes, however, the driving mechanisms of these biogeochemistry processes are still far from clear. In this study, a series of microcosms was constructed to simulate the mixed decomposition processes of aquatic plant residues with invasive algae as long as 205 days. Three aquatic plants (Potamogeton malaianus, Nymphoides peltatum, and Phragmites australis) and algae were collected from a typical eutrophic lake. The addition of algae promoted the decomposition of three plant residues based on the mass loss, and the positive co-metabolism effect was produced. The co-metabolism intensity was 8%–25% on the water surface and 19%–45% on the water-sediment interface, respectively. In addition, the response of three aquatic plant residues to the algal organic matter was different with their co-metabolism intensities in the order of P. australis > P. malaianus > N. peltatum on both the water surface and water-sediment interface. The phylum number of bacteria attached to the surface of plant residues increased from 27 to 52. The abundance of Bacteroidetes, which had the function of decomposing refractory organic matter, increased most significantly at the final incubation. At present, shallow lakes are under the double pressure of eutrophication and global warming, and the intensity and duration of algal blooms are increasing. Therefore, the co-metabolism effect of the residue decomposition process described here may change the carbon cycle strength and increase the greenhouse gas emissions of lakes and need to be taken into account in future lake management.

Allelopathic Effects of Amomum villosum Lour. Volatiles from Different Organs on Selected Plant Species and Soil Microbiota.

Amomum villosum Lour. is a perennial herb of the Zingiberaceae family, which is widely distributed in Xishuangbanna, Yunnan Province in Southwest China. Large amounts of volatile components contained in this plant enter the surrounding atmosphere and soil through volatilization, foliar leaching, root exudation, and residue decomposition. However, the ecological role of these compounds is currently unclear. The aim of this study was to compare the differences in the composition of volatile oils from stems, leaves, and young fruits of A. villosum, identify chemicals that had allelopathic effects, and explore the effects of the oil on the diversity and composition of soil microbiomes. Volatile oils were obtained by steam distillation and characterized by gas chromatography−mass spectrometry, and then were tested for allelopathic activity using seedlings of Lactuca sativa L. and Lolium perenne L. as test species. The results showed that the oils from stems and leaves were rich in monoterpene hydrocarbons, unlike the oxygenated monoterpenes which dominated oils from young fruits. Leaves > stems > young fruits: this was the order of the allelopathic effects of volatile oils from various A. villosum organs. Among the four main chemical components in the oils, only α-pinene, which is abundant in leaves, had a stronger allelopathic action than the crude oils, implying that it might be a potential allelochemical. Experiments on soil microorganisms indicated that 3.0 mg/mL oil had the greatest effect on the structure of the soil fungal community. It can be concluded that A. villosum is capable of releasing allelochemicals which affect the growth of other plant species and the diversity and community structure of soil microorganisms.

Potential inhibitors of FemC to combat Staphylococcus aureus: virtual screening, molecular docking, dynamics simulation, and MM-PBSA analysis

FemC is a methicillin resistance factor involved in the alterations of peptidoglycan and glutamine synthesis in Staphylococcus aureus. To identify the potent antibacterial agents, antibacterial molecules were screened against the predicted and validated FemC model. Based on docking scores, presence of essential interactions with active site residues of FemC, pharmacokinetic, and ADMET properties, six candidates were shortlisted and subjected to molecular dynamics to evaluate the stability of FemC-ligand complexes. Further, per residue decomposition analysis and Molecular Mechanics/Poisson-Boltzmann Surface Area (MMPBSA) analysis confirmed that S15, M16, S17, R31, R43, Q47, K48 and R49 of FemC played a vital role in the formation of lower energy stable FemC-inhibitor(s) complexes. Therefore, in the present study, the reported six molecules (Z317461228, Z92241701, Z30923155, Z30202349, Z2609517102 and Z92470167) may pave the path to design the scaffold of novel potent antimicrobials against S. aureus. Communicated by Ramaswamy H. Sarma

Early Effects of No-Till Use on Durum Wheat (Triticum durum Desf.): Productivity and Soil Functioning Vary between Two Contrasting Mediterranean Soils

The diffusion of no-tillage (NT) is to be encouraged because of the benefits it can provide in terms of improving soil fertility and counteracting global warming and climate change as part of climate-smart agriculture practices. However, the introduction of this management can be difficult, especially in the first years of application, and can lead to unpredictable yield results depending on the soil type. Therefore, the aim of this experiment was to evaluate the early effect of NT use, compared to the conventional mouldboard ploughing (CT), on two different soils, a clay-loam (GAL) and a sandy-clay-loam soil (SMA), by monitoring a set of 43 different soil and plant variables that were expected to vary with tillage and/or soil type. At both experimental sites, NT showed lower wheat total biomass (−29%) and grain yields (−17%) than CT with a more pronounced decrease in GAL than in SMA. Yield differences were accompanied by modifications in nutrient, microbial community and soil enzyme activity dynamics which highlighted higher stress in GAL, than in SMA soil, attributable to lower crop residues decomposition and substrate availability. Therefore, our findings suggest that the negative consequences due to the transition to NT depend on specific soil characteristics, like texture and organic matter concentration, with different repercussions on soil quality as well as on wheat growth and productivity.

Species evenness affects algae driven co-metabolism with aquatic plant residues

Understanding the mixed decomposition processes of aquatic plant residues is crucial for evaluating the carbon cycle of lakes. However, the complex effect of species evenness, and especially the algae driving co-metabolism effect in eutrophic lakes are still far from clear. In this study, three dominant aquatic plants (Phragmites australis, Nymphoides peltatum, and Potamogeton malaianus) and algae from the typical eutrophic and shallow Lake Taihu, China, were selected to simulate their mixed decomposition process. The addition of algae accelerated the mass loss of cellulose, hemicellulose, and lignin of aquatic plant residues and increased the total mass loss by 2.29~6.32% in mixed decomposition. The positive co-metabolism effect, with the intensity ranging from 10% to 17%, occurred during the mixed decomposition process. In addition, the positive co-metabolism effect was also found among plant residues during mixed decomposition and the co-metabolism intensity of species evenness mixed decomposition was more than twice as high as that of non-evenness mixed decomposition. The addition of algae during the decomposition of aquatic plant residues altered the stoichiometry of available nutrients and affected the microbial decomposition activity. The abundance of decomposition bacteria, especially Bacteroidetes, was increased and the community structure also changed, as evidenced by a 71% increase in the number of bacteria phylum. As a result, these biogeochemistry processes accelerated the decomposition rates of aquatic plant residues and thus produced the positive co-metabolism effect. Therefore, the co-metabolism effects of mixed decomposition described in this study are prevalent in eutrophication lakes and have important effects on the lake carbon cycle, which need to be considered in future lake management.Graphical

Влияние растительности на микрофлору полигонов твердых промышленных отходов в период рекультивации

The research was carried out at the stationary pilot site of LLC LUKOIL-Volgogradneftepererabotka located in the Volgograd region. Soil samples for microbiological analysis were taken from each variant of the experiment according to GOST 28168-89 from the upper root-inhabited horizon in the aisles and under shrubs Arónia melanocárpa, Rósa canína, Crataegus submollis, Hippophae rhamnoídes, Prúnus virginiána, Tamarix ramosissima. The most diverse communities of microorganisms were formed under the crowns of rosehip, hawthorn and cherry (16 generic complexes). The smallest number of genera was found under tamarix (12 genera) In soils with weakly occurring processes of mineralization of organic substances, imperfect fungi dominate, for which organic nitrogen is needed (Alternaria, Fusarium, etc.). The positive influence of shrubs on the microflora of the soil of recultivated objects was revealed. Saprophytic microflora prevails over pathogenic. In the experiment, the biological activity of soils containing oil sludge, according to the degree of decomposition of plant residues, depended on the growing shrubs and their organic matter. Under the crowns of Rósa canína, Prúnus virginiána and Arónia melanocárpa, it was 12.7-14.3 % higher than under the crowns of Tamarix ramosissima. It has been established that the microbiological activity of the soil increases, the process of restoring fertility and health accelerates. The greatest activity of microorganisms was detected under the crowns of rosehip, aronia, hawthorn and cherry. The leaves of these shrubs quickly turn into the organic matter of the soil, improving the conditions for the existence of soil microorganisms. Plantings of shrubs create phytomeliorative protection for grasses, which form a sufficiently large phytomass of leaves and stems (9.14 c/ha) at the end of the growing season. The resulting organic matter is nutrition for the microflora and contributes to the restoration of soil fertility.

Matching crop row and dripline distance in subsurface drip irrigation increases yield and mitigates N2O emissions

Intensive irrigation and nitrogen (N) fertilization are often linked to low N-fertilizer efficiency, and to high emissions of the greenhouse gas nitrous oxide (N 2 O). Efficient irrigation systems (e.g. subsurface drip irrigation [SDI]) combined with N-fertigation in a no-till agroecosystem can promote N-use efficiency, thereby curbing N 2 O emissions without depressing crop yield. Yet, crop type and SDI plant settings (and management) such as dripline spacing may determine the agronomic and environmental performance of SDI. In this two-year field study on maize ( Zea mays L.) - soybean ( Glycine max [L.] Merr.) rotation with conservation agriculture management (no-till and cover crops), we investigated the effects of three different irrigation/fertilization systems (SDI with a narrow dripline spacing (70 cm) + fertigation with ammonium sulphate, SDI with a large dripline spacing (140 cm) + fertigation with ammonium sulphate, and sprinkler irrigation [SPR] + granular urea application) on yield, N-fertilizer efficiency, and N 2 O emissions in a fine-textured soil. We hypothesized that SDI systems (especially with narrow dripline distance) would increase yield and mitigate N 2 O compared with SPR, and particularly for maize due to its higher water and nutrient demand. We found that SDI increased maize yield (+31%) and N-fertilizer efficiency (+43–71%). These positive results were only observed during the drier year in which irrigation supplied ca. 80% of maize water requirements. The narrower dripline spacing mitigated N 2 O emissions compared with sprinkler irrigation (by 44%) and with the wider spacing (by 36%), due to a more homogeneous distribution of N in soil, and to a lower soil moisture content. Soybean yield and N-use efficiency were not affected by the irrigation systems. We also found that SPR enhanced cover crop residue decomposition, thus promoting the release of C and N into the soil and increasing N 2 O emissions. Overall, our study provides important insights on key management decisions that define the sustainability of novel irrigation systems; in particular SDI with a 70 cm dripline distance should be promoted for maize to increase productivity and decrease N 2 O emissions in fine-textured soils. • Benefits of SDI increases with high water and N demanding crops. • SDI increases maize yield and N-fertilizer efficiency during dry years. • Narrow dripline distance (0.70 m) mitigates N 2 O emissions. • N release from litter decomposition may play a major role in N 2 O emissions.

The involvement of organic acids in soil fertility, plant health and environment sustainability.

Increasing demand for safe food by an ever-growing human population emphasizes the urgency for increasing crop yields and reducing the losses caused by abiotic and biotic stresses; a partial solution to this problem is to develop a better understanding of plant-microbe interactions. Plant roots continuously release a wide range of compounds including organic acids in root exudates. These root exudates stimulate growth of specific microbial communities in the rhizosphere, which affect complex biological and physico-chemical interactions occurring between plant roots and the surrounding soil environment. In addition, organic acids are also released by different microbes and during decomposition of organic matter and plant residues in the soil. Interestingly, the available organic acids in the rhizosphere play crucial roles in various physio-chemical processes including the chemoattraction of microbes (both beneficial and pathogenic), mineralization and solubilization of complex minerals (P, K and Zn), biocontrol of phytopathogens, induction of systemic resistance, biogas formation, mitigation of abiotic stresses and, detoxification of metals and residual pesticides. Thus, organic acids play a significant role in the sustainable management of the soil ecosystem and in environmental sustainability. This review discusses the role of organic acids in the stimulation or enrichment of specific root-associated microbial communities and their effect on plant-microbe interactions at the root surface. In addition, the potential for root microbiome modification to enhance nutrient cycling and nutrient acquisition, and in amelioration of environmental stresses for increasing food production is discussed.

Multi-material spectral photon-counting micro-CT with minimum residual decomposition and self-supervised deep denoising.

Spectral micro-CT imaging with direct-detection energy discriminating photon counting detectors having small pixel size (< 100×100 µm2) is mainly hampered by: i) the limited energy resolution of the imaging device due to charge sharing effects and ii) the unavoidable noise amplification in the images resulting from basis material decomposition. In this work, we present a cone-beam micro-CT setup that includes a CdTe photon counting detector implementing a charge summing hardware solution to correct for the charge-sharing issue and an innovative image processing pipeline based on accurate modeling of the spectral response of the imaging system, an improved basis material decomposition (BMD) algorithm named minimum-residual BMD (MR-BMD), and self-supervised deep convolutional denoising. Experimental tomographic projections having a pixel size of 45×45 µm2 of a plastinated mouse sample including I, Ba, and Gd small cuvettes were acquired. Results demonstrate the capability of the combined hardware and software tools to sharply discriminate even between materials having their K-Edge separated by a few keV, such as e.g., I and Ba. By evaluating the quality of the reconstructed decomposed images (water, bone, I, Ba, and Gd), the quantitative performances of the spectral system are here assessed and discussed.

Experimental investigation and numerical modeling of oxidative pyrolysis mechanism of mining PVC cable sheath

Cables modified with flame retardants are widely used in the coal mining process to enhance their fire safety performance. This paper investigates experimentally and numerically the thermo-oxidative degradation process of PVC-based mining cable sheath, which consists of PVC resin and plasticizers (Phthalate esters), fillers (Calcium carbonate), and flame retardant (Antimony trioxide) as additives. Thermogravimetry coupled with Fourier transform infrared spectroscopy (TG-FTIR) experiments were performed at different heating rates in an air atmosphere. TG results showed that the decomposition processes of mining PVC cable sheath are more complicated than those of pure PVC with additional degradation steps, which was further confirmed by FTIR gas analysis. A deconvolution method was used to distinguish the independent reactions from the overlapped derivative thermogravimetric (DTG) peaks. It was found that the whole degradation process can be divided into seven steps, based on which an oxidative pyrolysis model was developed: pyrolysis of plasticizers (steps 1 and 2), dehydrogenation (step 3), emission and combustion of volatile fraction (step 4), carbon combustion (step 5), oxidative pyrolysis of complicated additives (step 6), and decomposition of residues (step 7). The kinetic triplets (activation energy, pre-exponential factor, and reaction model function) for each reaction were firstly calculated using three commonly used model-free methods and then further optimized using the genetic algorithm (GA). Based on the optimized parameters, the reaction mechanisms and their associated kinetic parameters were determined. The findings of this study are important in understanding the oxidative pyrolysis process of PVC cable sheath, and the obtained kinetic parameters can also be used for its pyrolysis and fire modeling, waste recycling, and risk assessment.

Effects of the Decomposition of Mixed Plant Residues in Ecological Tea Garden Soil

(1) Background: Plant litter decomposition and its effect on soil nutrients are important parts of the ecosystem material cycle, and understanding these processes is key for species selection and allocation, to promote the effective use of litter in ecological tea gardens. (2) Methods: In situ decomposition was used in this study Changes in decomposition rate, element release, and soil properties during the decomposition of the mixed plant residues were measured. (3) Results: The decomposition rate (k) of the CCG (Camellia sinensis + Cinnamomum glanduliferum) mixed plant residue was significantly higher than that of the CS (Camellia sinensis) residue. The decomposition of the CCG, CPM (C. sinensis + Pinus massoniana), and CBL (C. sinensis + Betula luminifera) mixed plant residues showed an additive effect, whereas that of the CCL residue showed an antagonistic effect. The CBL mixed plant residue promoted the release of N; the decomposition of the CCG, CPM, CCL (C. sinensis + Cunninghamia lanceolata), and CBL residues promoted the release of TC (total carbon); and the decomposition of the CCG residue promoted the release of cellulose. After 428 d of decomposition, the four mixed plant residues had improved the soil nutrient contents to some extent. CCG and CBL residue decomposition resulted in greater improvements in soil nutrients. (4) Conclusions: The application of the mixture of material obtained by pruning C. glanduliferum, B. luminifera, and C. sinensis in an ecological tea garden accelerated the decomposition and nutrient release rates, increased soil nutrient contents, shortened the decomposition turnover period of plant residues, and accelerated the nutrient cycle of plant residues in the ecological tea garden.

Оптимизация питательного режима озимой пшеницы

Abstract. Efficient and rapid decomposition of plant residues, and elimination of the negative impact of pathogenic microflora on the soil environment and the plant organism occurs due to fungi of the genus Trichoderma, which have phytoprotective and growth-promoting properties, have a high degree of decomposition of high-polymer components of plant residues. One of these drugs is Sternifag. The article presents the results of studies that determine the effectiveness of the use of the microbiological preparation Sternifag in the technology of cultivating winter wheat. The research was carried out at the Adyghe research institute of agriculture in the period 2017–2020 gg. on leached chernozem. As a result of the research, it was noted that the use of the Sternifag preparation increased the height of winter wheat, which was 37,4 cm in the booting phase (+39,6 % of the control) and 81,9 cm in the full ripeness phase (+8,9 % to control), the growth of biomass by aboveground organs and their accumulation of dry matter also increased. The inclusion of the Sternifag preparation in the winter wheat cultivation technology significantly increased the yield by 11,2 (low agrobackground) and 9,3 (high agrobackground) % in comparison with the options without its use. The maximum yield – 4,01 t/ha, was obtained on option 4 with the Sternifag preparation, on a high agricultural background. It was determined that the use of this drug in the cultivation of winter wheat improved the protein content in the grain, its nature, and vitreousness. At the same time, it slightly affected gluten and its quality, which determined the grain class, which corresponded to 5 on a low agricultural background, and 4 on other options.

Atomistic insights into the binding of SARS-CoV-2 spike receptor binding domain with the human ACE2 receptor: The importance of residue 493

SARS-CoV-2 is a coronavirus that has created a global pandemic. The virus contains a spike protein which has been shown to bind to the ACE2 receptor on the surface of human cells. Vaccines have been developed that recognize elements of the SARS-CoV-2 spike protein and they have been successful in preventing infection. Recently, the Omicron variant of the SARS-CoV-2 virus was reported and quickly became a variant of concern due to its transmissibility. This variant contained an unusually large number (32) of point mutations, of which 15 of those mutations are in the receptor binding domain of the spike protein. While several computational and experimental investigations comparing the binding of the Omicron and wild type RBD to the human ACE2 receptor have been conducted, many of these report contradictory findings. In order to assess the differential binding ability, we conducted 2 μs of classical molecular dynamics (cMD) simulation to estimate the binding affinities and behaviors. Based upon MM-GBSA binding affinity, per-residue energy decomposition analysis, center of mass distance measurements, ensemble clustering, pairwise residue decomposition and hydrogen bonding analysis, our results suggest that a single point mutation is responsible for the enhanced binding of the Omicron mutant relative to the WT. While the 15-point mutations in the receptor binding domain contribute positively and negatively to the affinity of the spike protein for the human ACE2 receptor, it is the point mutation Q493R that confers enhanced binding while the Q493K mutation results in similar binding. The MM-GBSA binding estimations over a 2 μs trajectory, suggest that the wild type binds to ACE2 with a value of −29.69 kcal/mol while the Q493K and Q493R Omicron mutants bind with energy values of −26.67 and −34.56 kcal/mol, respectively. These values are significantly different, given the error estimates associated with the MM-GBSA method. In general, while some mutations increase binding, more mutations diminish binding, leading to an overall similar picture of binding for Q493K and enhanced binding for Q493R.

In silico pharmacokinetics, molecular docking and dynamic simulation studies of endolichenic fungi secondary metabolites: An implication in identifying novel kinase inhibitors as potential anticancer agents

Herein, seventy three (73) anticancer metabolites from different endolichenic fungi which are reported previously, were analyzed for drug likeliness and pharmacokinetic properties using SwissADME, ADMETlab, and admetSAR. The desirable compounds were studied using molecular docking against three clinically important human kinases: pyruvate kinase isoform 2, hexokinase II, and phosphoglycerate kinase. The results displayed a significant binding affinity of the test ligands against the kinases compared to 3-bromopyruvic acid, a reference glycolytic inhibitor. Pharmacokinetics and binding interactions of three compounds including talaromycin A, pyridoxatin, and terricollene A were predicted to be substantial. Terricollene A bound complexes were found to have the most considerable binding free energies and therefore were investigated for their conformational stability and compactness under explicit water conditions using molecular dynamics simulation up to 100 ns. The residual decomposition of binding energies for each of the complexes was calculated using Molecular Mechanics Poisson–Boltzmann Surface Area (MM-PBSA) method. The results demonstrated substantial stability and compactness of terricollene A-kinase complexes. The findings will facilitate the development of potential glycolytic inhibitors for treating and controlling several forms of cancer; however, supplementary experimental investigations to evaluate the efficacy of the test ligand are warranted.

Dynamics of microbiota and physicochemical characterization of food waste in a new type of composter

Organic wastes are considered the most significant components of urban solid waste, negatively affecting the environment. It is essential to use renewable resources to minimize environmental risks. Composting is one of the most sustainable methods for managing organic waste and involves transforming organic matter into a stable and nutrient-enriched biofertilizer, through the succession of microbial populations into a stabilized product. This work aimed to evaluate the efficiency of the new type of composter and the microbial and physiochemical dynamics during composting aiming to accelerate the degradation of organic waste and produce high-quality compost. Two inoculants were evaluated: (1) efficient microorganisms (EM); (2) commercial inoculum (CI), which were compared to a control treatment, without inoculation. Composting was performed by mixing organic waste from gardening with residues from the University's Restaurant (C/N ratio 30:1). The composting process was carried out in a 1 m3 composter with controlled temperature and aeration. The thermophilic phase for all treatments was reached on the second day. Mature compost was obtained after an average of 120 days, and composting in all treatments showed an increase in the availability of P and micronutrients. The new composter helped to accelerate the decomposition of residues, through the maintenance of adequate oxygen content and temperature control inside the cells, providing high metabolic activity of microorganisms, contributing to an increase in physicochemical characteristics, also reducing the composting time in both treatments. During composting, the bacteria and actinobacteria populations were higher than yeasts and filamentous fungi. The inoculated treatments presented advantages showing more significant mineralization of P-available and micronutrients such as Mn and Zn in terms of the quality of the final product in comparison to the control treatment. Finally, the new composter and the addition of inoculants contributed significantly to the efficiency of the process of composting organic waste.

Environmental and Energy Analysis of Two Orchard Systems: A Case Study in Mediterranean Environment

This paper aimed to analyse and compare the environmental and energy sustainability of two orchards (peach versus kiwifruit) located in Southern Italy using Life Cycle Thinking. To this end, anthropogenic energy, CO2 emissions, biogenic energy and carbon gains were also considered through Life Cycle Assessment methodology and Energy Analysis. The C–CO2 balance was calculated as the difference between total C–CO2 stored in soil and trees, at the end of their life cycles, and orchards Carbon Footprint (CF). The results showed that the production of 1 kg of peaches caused minor impacts, especially with reference to CF (0.124 kg CO2 eq against 0.145 for kiwifruit), while it required 1.56 MJ of energy against 1.32 MJ for kiwifruit. In both orchards the main sources of direct CO2 emissions came from fuel combustion, nitrous oxide release by crop residue decomposition, and nitrogenous fertilizer distribution. Nevertheless, both orchards had sustainable environmental and energy results. Despite the management of the orchards releasing CO2 and consuming energy, they showed a significant capacity to store CO2 and energy, proving to be virtuous systems. This research can give useful indications for farmers, farmer associations, technicians, and stakeholders to improve orchard management efficiency. The net balance approach seems to be an adequate strategy, allowing best estimation of environmental impacts and guiding farmer decisions towards more sustainable alternatives.

Multiscale model reduction for stochastic elasticity problems using ensemble variable-separated method

Elasticity is a fundamental model in mechanics and material sciences. In the article, we present an ensemble variable-separated multiscale method for elasticity problems in random media. A variable-separated method is utilized to provide a low-rank approximation for random fields. The variable-separated method is integrated with the Generalized Multiscale Finite Element Method (GMsFEM) to obtain an efficient reduced model. To this end, a few local problems are solved for snapshots to construct the multiscale basis functions in GMsFEM. An ensemble method is used to construct stochastic basis functions shared by a series of elasticity equations, and a residual decomposition is adopted to calculate the deterministic physical components for all ensemble members. The ensemble variable-separation is used to solve the local problems of the multiscale basis functions and achieves efficient online-computation for the basis. Then, under the Galerkin projection of the generalized finite element method, the solutions of stochastic elasticity problems are projected onto the low-dimensional space spanned by the online multiscale basis functions. This renders an effective coarse model. The ensemble variable-separated multiscale method is applied to steady-state elastic deformation and elastic wave propagation in random media. A few numerical results are carried out to demonstrate the accuracy and efficiency of the presented method.

Mechanism of ultrahigh ductility obtained by globularization of αGB for additive manufacturing Ti–6Al–4V

In the present work, two post-processes, the 800 °C and 950 °C for 4 h annealing below β transus, were designed to improve the performance of selective laser melted (SLM) Ti–6Al–4V (Ti64) alloy. The results show that 800 °C annealing raises the ductility to 18%, while 950 °C annealing raises the ductility high up to 26%. Although the residual stress relief and martensite decomposition fully accomplished in both annealed samples, there is still a noticeable difference in ductility. The difference is due to that 950 °C annealing induce noticeable globularization which further alters the fracture mode. Further study indicates that with globularization of αGB phase (α phase along prior β grain boundary), the transgranular fracture replaces the detrimental intergranular fracture. Particularly, the high angle grain boundary (HAGB) between equiaxed αGB phase effectively inhibits the initiation and propagation of crack, when comparing to the low angle grain boundary (LAGB) in α lamella. The reason for globularization in 950 °C annealing could be concluded as the boundary splitting model. The β phase grow along the LAGB in α lamella and form thermal grooving. With the groove deepening, the lamella was separated into equiaxed α phase. In this process, high temperature annealing promotes sufficient bulk diffusion, which is a necessary condition for globularization of lamellar α phase in SLM Ti64 alloy.