Different Degrees Of Decomposition Research Articles

Soil Quality in Rehabilitated Coal Mining Areas

In arid and semiarid environments, the sustainability of rehabilitation actions in degraded areas is a matter of concern. It has not been extensively researched. In a Spanish coal mining area, new soils to support vegetation were created (Technosols) using mine spoils and different organic wastes. Eight years after the establishment of rehabilitation measures, the quality of the works was assessed. Soil properties (organic matter, microbial biomass, structural stability and porosity) were evaluated as quality indicators. Thermogravimetric analysis differentiated between organic-C and other mineral-C sources. The degree of aggregation and the presence of interconnected pores and organic matter with different degrees of decomposition were identified by micromorphological techniques. Microbial biomass and water-stable aggregates satisfactorily traced the early pedogenesis of mine spoils, resulting in good indicators of the quality of new Technosols. Substrates prepared with sludges promoted soil development better than those created using pig slurries, primarily by favoring a higher porosity and organic matter content. Despite that, both treatments demonstrated, after 8 years, their ability to support the ecosystem services of biomass production, carbon sequestration, and organic matter recycling they were planned for, therefore ensuring their sustainability.

African Vernacular Symbols of Black Intersex Children in Sinethemba Ngubane's Installations (2007-2016)

African Vernacular Symbols of Black Intersex Children in Sinethemba Ngubane's Installations (2007-2016)

Binding of per- and polyfluoroalkyl substances (PFASs) by organic soil materials with different structural composition – Charge- and concentration-dependent sorption behavior

The charge- and concentration-dependent sorption behavior of a range of per- and polyfluoroalkyl substances (PFASs) was studied for three organic soil samples with different organic matter quality, one Spodosol Oe horizon (Mor Oe) and two Sphagnum peats with different degrees of decomposition (Peat Oi and Peat Oe). Sorption to the two peat materials was, on average, four times stronger compared to that onto the Mor Oe material. In particular, longer-chained PFASs were more strongly bound by the two peats as compared to the Mor Oe sample. The combined results of batch sorption experiments and 13C NMR spectroscopy suggested sorption to be positively related to the content of carbohydrates (i.e., O-alkyl carbon). Sorption of all PFAS subclasses was inversely related to the pH value in all soils, with the largest pH effects being observed for perfluoroalkyl carboxylates (PFCAs) with C10 and C11 perfluorocarbon chain lengths. Experimentally determined sorption isotherms onto the poorly humified Peat Oi did not deviate significantly from linearity for most substances, while for the Mor Oe horizon, sorption nonlinearity was generally more pronounced. This work should prove useful in assessing PFAS sorption and leaching in organic soil horizons within environmental risk assessment.

SF 6 decomposition and insulation condition monitoring of GIE: A review

The statistics of the Conference International des Grands Reseaux Electriques (CIGRE) indicate that the operational reliability of SF6 gas-insulated equipment (GIE) is very high; however, the failure rate of the GIE in operation is much higher than that of the IEC standard, and the fault occurs frequently in the GIE at a high voltage level. The reason is due to the complex and strong on-site electromagnetic interference environment and fully enclosed structure of GIE. The key method and technology for effective on-line monitoring and fault diagnosis of GIE are still lacking. Given the partial strong electromagnetic energy and high temperature induced by early latent insulation faults in the equipment, SF6 gas insulation presents different degrees of decomposition. The decomposition products mainly include SO2F2, SOF2, SO2, HF, and H2S. The decomposition characteristics of SF6 are closely related to the property of insulation faults. At present, this area is attracting attention from the power industry and research institutes. This study summarises the current research on SF6 decomposition component analysis (DCA). The content mainly includes the latest progress of SF6 decomposition characteristics and mechanism under fault conditions, and fault diagnosis methods based on decomposition components.

Analysis of peat soil organic carbon, total nitrogen, soil water content and basal respiration: Is there a ‘best’ drying temperature?

Soil needs to be dried in order to determine water content, soil organic carbon content (SOC) and total nitrogen content (N). Water content is commonly measured using standard methods that involve drying temperatures of 105–110 °C. Recommended drying temperatures differ for the determination of SOC and N. However, at moderate drying temperatures, microbial activity might lead to organic matter mineralisation and nitrification, and thus to an underestimation of SOC and N. Furthermore, low drying temperatures might not dewater soils sufficiently to correctly determine water content or bulk density. Chemical processes such as thermal decomposition and volatilisation might occur at higher temperatures. This raises the question of whether the same sample can be used to determine water content, SOC and N. Further, the effect of drying, especially at different temperatures, on basal respiration of peat soils determined by incubation experiments is so far unknown. Effects of drying temperature might be especially severe for peat soils, which have high SOC and water contents.This study systematically evaluated the effect of different drying temperatures (20, 40, 60, 80 and 105 °C) on the determination of mass loss (proxy for water content), SOC and N over a wide range of 15 different peat soils comprising amorphous, Sphagnum and sedge peat substrate. The investigated peat soils had SOC contents ranging from approximately 16.8–52.5% with different degrees of decomposition. They were thus separated into two ‘peat groups’ (amorphous and weakly decomposed). In a subsequent investigation, an incubation experiment was carried out on a subset of five peat soils to investigate the pre-treatment effect of different drying temperatures on basal respiration. The results showed that amorphous samples should be dried at 105 °C to determine water content. The weakly decomposed peat soils in the study had reliable water contents for drying temperatures above 60 °C. For temperatures below 80 °C, the determined SOC and N were biased by residual water. This could be corrected for weakly decomposed samples, but for amorphous samples only for drying temperatures ≥60 °C. Thus, mineralisation of soil organic matter is likely to take place at lower drying temperatures which are not recommendable especially for amorphous peat prone to high mineralisation rates. This is supported by the results of the incubation experiment: The effect of peat type (amorphous topsoil vs. weakly decomposed subsoil) was greater than the effect of different drying temperatures, which nonetheless affected respiration rates. The differences between all five soils were consistent, irrespective of the drying temperature. Thus, incubation experiments might be possible using peat dried at moderate temperatures.

Sulfate Mobility in Fen Peat and Its Impact on the Release of Solutes

Sea-level rise coupled with land subsidence from wetland drainage exposes increasingly large areas of coastal peatlands to seawater intrusion. Seawater contains high concentrations of sulfate (SO42-), which can alter the decomposition of organic matter thereby releasing organic and inorganic solutes from peat. In this study, a flow-through reactor system was used in order to examine the transport of SO42- through peat as well as its effect on solute release. Moderately-decomposed fen peat samples received input solutions with SO42- concentrations of 0, 100, 700 and 2700 mg L-1; sample effluent was analyzed for a variety of geochemical parameters including dissolved organic carbon (DOC), dissolved inorganic carbon (DIC) and total dissolved nitrogen (TDN) as well as the concentrations of major cations and anions. The input solution remained anoxic throughout the experiment; however, no signs of a pronounced SO42- reduction were detected in the effluent. SO42- transport in the fen peat resembled non-reactive bromide (Br-) transport, indicating that in the absence of SO42- reduction the anion may be considered a conservative tracer. However, slightly elevated concentrations of DOC and TDN, associated with raised SO42- levels, suggest the minor desorption of organic acids through anion exchange. An increased solute release due to stimulated decomposition processes, including SO42- reduction, was observed for samples with acetate as an additional marine carbon source included in their input solution. The solute release of peats with different degrees of decomposition differed greatly under SO42--enriched conditions where strongly-decomposed fen peat samples released the highest concentrations of DOC, DIC and TDN. Overall, besides a cation-exchange related release of substances adsorbed in the peat, an input of increased SO42- concentrations in a peatland by itself might not lead to an increased solute release in the short-term. However, once SO42- reduction has commenced following long-term anoxic conditions or due to a biologically readily degradable carbon source, a SO42- input can stimulate the release of solutes, including DOC, DIC and TDN, from peat.

Thematic micro‐maps of soil components using high‐resolution spatially referenced mosaics from whole soil thin sections and image analysis

SummaryIn the quantification and analysis of the distribution of soil basic components, factors such as spatial resolution, scales of observation and analytical techniques used to interpret digital images of microscopic platforms are critical to obtain reproducible results. In addition, individual or discrete images, sometimes with high spatial resolution, distort features or basic components when zooming in or out, which limits their classification. This research proposes the use of micromorphological tools, spatially referenced mosaics with high resolution, image analysis and composite images to elaborate thematic maps of soil components. Therefore, we created mosaics with sequential digital images from soil thin sections (up to 3850 mm2) of different diagnostic horizons, with different magnifications (2×, 10× and 20×) and light sources. The mosaics (between 0.25 and 2.6 μm2 per pixel, and between 2 and 8 GB file size) were processed by image analysis (segmentation, supervised classification and accuracy assessments) for delimiting their basic soil components from composite images and with spatial operators to elaborate thematic maps at the microscopic level. The RGB (red, green, blue) brightness values of each soil component with different light sources enabled us to identify and quantify size classes of aggregates, voids, pedofeatures and organic matter with different degrees of decomposition at a high level of precision (up to 99% overall accuracy). It was also possible to develop good‐quality thematic maps of such components from high‐resolution spatially referenced mosaics and composite images Thematic maps of soil components can be explored without losing their spatial reference and analysed on multiple scales from a whole soil thin section.Highlights Micromorphology and digital cartography to develop thematic maps of soil components High spatial resolution mosaics from thin sections and image analysis were used for mapping RGB brightness values of different light sources facilitated mapping of soil features Accurate maps enabled quantification and analysis of spatial relations of soil components

Impact of MSW compression on methane generation in decelerated methanogenic phase

This study investigated the impact of compaction on anaerobic degradation of municipal solid waste (MSW) during the phase of decelerated methane formation. Two stainless steel lysimeters were constructed by equipping a hydraulic cylinder to apply pressure load on the MSW. When methane production rates decreased from the peak rate of each column, pressure load was applied at different degrees of decomposition (DOD). Methane production rate increased when compaction was applied. However, the impact of compaction on the methane production rate varied according to DOD. The MSW compaction reduced MSW pore space, increasing the contact surface area among MSW lumps. It was hypothesized that the mass transfer of substrate and substrate accessibility could be enhanced due to the decrease of void space and the increase of the contact area among waste mass as a consequence of the compaction.

Microfluidic Superheating for Peptide Sequence Elucidation.

Herein, we introduce microfluidic superheating as a new method for peptide fragmentation prior to mass spectrometric analysis. The superheating conditions were found to be stable up to 240 °C for more than 30 min without elevated pressure or boiling of the aqueous sample. As proof of principle, we exposed the peptides ACTH1-10 and OVA257-264 to various superheating conditions, causing different degrees of decomposition. Optimized superheating conditions resulted in the entire peptide ladder sequence of the y-ions, allowing the amino acid sequence to be deduced from a single-stage mass spectrum. Thus, obtaining information in the same quality as from tandem mass spectrometry can be achieved by a single superheating step.

Caracterização de Organossolos em ambientes de várzea do nordeste do Brasil

Os Organossolos são geralmente associados às regiões Sudeste e Sul do Brasil, e são poucos os estudos sobre a ocorrência e os efeitos do uso e manejo agrícola desses solos na região Nordeste. Os objetivos deste trabalho foram caracterizar física, química e morfologicamente seis perfis de Organossolos de várzeas dos Estados do Ceará, Rio Grande do Norte e da Paraíba e correlacionar seus atributos ao ambiente de formação, além de quantificar seus estoques de carbono e suas capacidades de armazenamento de água. Foram utilizados os métodos recomendados no Sistema Brasileiro de Classificação de Solos (SiBCS) para caracterizar química e fisicamente o solo, bem como a umidade e o volume residual dele. O aumento dos valores da Ds nos horizontes foi em decorrência da maior decomposição das fibras esfregadas (FE) e da redução dos teores de matéria orgânica. O volume residual apresentou correlações positiva e significativa a 5 % com o valor de resíduo mínimo (r = 0,64) e Ds (r = 0,74) e negativa com a porcentagem de FE (r = -0,75), podendo ser usado para avaliar a subsidência desses solos. As propriedades químicas foram influenciadas pelo material orgânico e pelos sedimentos fluviomarinhos. A variação da drenagem influenciada pela posição no relevo e pelo uso agrícola dos solos conduziu a classes de diferentes graus de decomposição da matéria orgânica e com isto às classes dos Organossolos Fíbrico, Hêmico e Sáprico. Um dos perfis CE1, com maior influência de sedimentos marinhos, foi classificado como Organossolo Tiomórfico com caráter solódico.

Phenolic compounds of sphagnum peat

The results of studies of various phenolic compounds, which are the constituents of Sphagnum magellanicum peat of different degrees of decomposition, showed that it is characterized by high concentrations of free phenol compounds, which include phenolcarboxylic acids, catechols, and flavonols. It was found that an increase in the degree of decomposition leads to a decrease in phenolcarboxylic acids in the composition of peat with a simultaneous considerable increase in the concentration of flavonols—an important group of biologically active phenol compounds.

Effects of Waste Composition and Decomposition on the Shear Strength of Municipal Solid Waste

AbstractThe objective of this study was to evaluate the effects of waste composition and decomposition on the shear strength of municipal solid waste. Waste was collected from two sources (an operating landfill and a transfer station) and degraded in laboratory anaerobic reactors to prepare wastes with different degrees of decomposition. Shear strength was measured in a 280-mm-diameter direct shear ring on nine wastes with normal stress ranging between 12 and 90 kPa. The Mohr-Coulomb failure criterion was used to determine shear strength parameters (ϕ = friction angle and c = cohesion intercept) of the wastes, and shear strength was selected at a horizontal displacement of 56 mm (i.e., 20% of the specimen diameter). A composite failure envelope regressed through shear strength versus normal stress data from all wastes was statistically significant, with ϕ=37° and c=20 kPa. A comparison between tests conducted in this study and in the literature indicates that larger ϕ are obtained for waste with a greater...

Influence of Clay Addition on Physical Properties and Wettability of Peat-growing Media

The role of clay incorporation on the physical properties and wettability of peat-growing media was assessed from water retention curves and from contact angle and water drop penetration time measurements, respectively. Two peat substrates presenting different degrees of decomposition (weakly and highly decomposed Sphagnum peat) were used and mixed with clay in the form of powder with a peat:clay ratio of 90:10 (by vol.). Results indicated relatively little change in water retention resulting from clay incorporation in the peat-growing media tested. On the other hand, they showed a significant improvement of the wettability of both substrates in the driest conditions when peat-growing media presented a pronounced hydrophobic character, whereas the wettability of materials was not changed in the wettest conditions when they were largely hydrophilic. The influence of the degree of peat decomposition was also observed with somewhat higher wettability for the weakly decomposed peat:clay mixture than for the highly decomposed peat:clay mixture. Because the hydrophobic character of highly decomposed peat is more pronounced and appears at a higher water content than weakly decomposed peat, the effect of clay addition also appears at higher water contents for highly decomposed peat. Incorporating clay into peat-growing media should be considered for its ability to improve the wettability of growing media with a hydrophobic character (i.e., to improve the ability of the growing media to be rewetted) rather than only its ability to influence the water retention characteristics of the growing media.

MICROBIOLOGICALLY IMPROVED PEAT-BASED MEDIA FOR NURSERY PRODUCTION BY ADDITION OF ARBUSCULAR MYCORRHIZAL FUNGI

MICROBIOLOGICALLY IMPROVED PEAT-BASED MEDIA FOR NURSERY PRODUCTION BY ADDITION OF ARBUSCULAR MYCORRHIZAL FUNGI

A Qualitative Study of Compact Bone Microstructure and Nuclear Short Tandem Repeat Obtained From Femur of Human Remains Found on the Ground and Exhumed 3 Years After Death

Forensic identification of human remains is composed of anthropological study of race, sex, age, etc. By using these traditional methods, inconclusive or nonidentified cases could be subjected to DNA analysis. However, in spite of advances in human identification techniques, especially by PCR-amplified DNA, some limitations that affect the ability of obtaining DNA from human remains still persist. Light microscope sections of postmortem compact bones from human remains are presented here for the purpose of increasing a forensic examiner's prediction of successful nuclear DNA typing. Femoral compact bones were obtained from 7 human remains found on the ground, in different degrees of decomposition, and were cleaned by boiling to remove soft tissues, 8 collections of bones having undergone natural decomposition, not boiled (as no soft tissue was adhered), and 5 cadavers 12 to 16 hours postmortem. The histologic sections were stained by hematoxylin and eosin, the loci CSF1PO, TPOX, TH01, F13A01, FESFPS, vWA, D16S539, D7S820, D13S317, and amelogenin were amplified by PCR, and the polyacrylamide gel was stained with silver. The results presented here clarify questions concerning the viability of DNA for identification analysis, and they also may help to establish better strategies for optimization of DNA extraction and analysis in compact bones of human remains.

Application of compact ultrasound imaging device to postmortem diagnosis

In regions with low autopsy rates, forensic examiners often have to rely on external findings. Imaging techniques can assist the external examination and provide a more objective diagnosis. The SonoSite™180, a portable ultrasound device, was used for the examination of dead bodies. The influence of different degrees of decomposition was estimated. Even in cases with intestinal gas formation images of internal organs could be obtained with special techniques. Various pathological findings were detected by ultrasound and verified by autopsy (e.g. pericardial tamponade, cardiac hypertrophy, fatty liver, aortic aneurysm, metastatic liver, etc.). The experiences with the SonoSite™180 are promising. The device can be carried to the death scene or to the morgue and therefore serve as a valuable tool for medicolegal applications.

Sur le role de la vegetation dans le stockage du soufre dans les sols de mangrove (Senegal). Resultats preliminaires

Upon the role of vegetation in sulfur storage in mangrove soils (Senegal). Preliminary results. Plant organs, plant residues at different degrees of decomposition, and the surface soil (0–5 cm) of a Rhizophora mangrove in Saloum Island (Sénégal) were analyzed for total C,N,S and amino acid content and for sulfur isotopical composition (δ 34S). These preliminary results emphasize the possible role of vegetation (roots and leaves) on S storage in mangrove soils.

Relation between flow, power, and presence of carrier gas during plasma deposition of thin films

Plasma deposition processes have become an integral part of the manufacturing of microelectronic devices. Control of proper deposition parameters and understanding their relation to the composition of the plasma, and therefore to the film properties, is essential for depositing films in a repeatable and a predictable way. Using mass spectrometry, we have studied the influence of input rf power, reactant gas flow, and the presence and concentration of carrier gas on the degree of decomposition of a wide range of starting materials used during plasma deposition. It is shown that all three parameters influence the decomposition of the starting material and therefore the composition and properties of the deposit. It is also shown that different degrees of decomposition for different materials cannot always be predicted from the bonding energy between species being dissociated by a plasma. Using silicon nitride as an example, it is shown that the N/Si atomic ratio in films deposited at various conditions corresponds to the relative degree of decomposition of the reactant gases NH3 and SiH4.

Some Aspects of Precipitation and Magnetic Properties of Alnico Alloys

I. Single crystals of Alnico V and Alnico VIII alloys with 35, 40, and 42 wt.% Co and 5, 7, and 8 wt.% Ti, respectively, were investigated by x-ray analysis and electron microscopy of thin foils. It was found: (1) In Alnico V, alloy decomposition begins with the formation of randomly arranged equiaxial spherical zones. When the tempering temperature and time increase, at first very short-range ordering appears in their arrangement, and then an entire periodic modulated structure is formed. At later stages, rod-shaped particles are formed, then metastable tetragonal phases, and at least, two cubic phases. (2) In Alnico VIII-type alloys with an increased content of Co and Ti, volume changes during decomposition are significantly greater, and the role of elastic energy is decisive. So a three-dimensional periodically modulated structure forms even during the quenching process. These structure elements are mainly equiaxial precipitates which intergrow in rods in some places. During tempering, the number of rod-shaped formations increases, and continuous transformation from the modulated structure to tetragonal phases takes place. Two cubic phases form at later tempering stages. (3) Transformation from the modulated structure to tetragonal phases is not accoupanied by changes in alloy structure morphology but are seen in x-ray scattering results. The tetragonal phases have equal ``c'' periods along the cubic axis but different ``a'' periods. This is accounted for by an alloy structure morphology in which there are interconnected rod-shaped particles quasicoherent with the matrix (phase lattice periods coincide only along the c axis). In the state of optimum magnetic properties, the structure of all the investigated alloys consists of two tetragonal phases with the following parameters: α-phase Åα′-phase ÅItem Nos.Alloyacc/aacc/a1Alnico V2.8762.8720.9982.8702.8721.0012Alnico VIII2.9092.8730.9872.8552.8731.0063Alnico VIIIa2.9092.8720.9872.8502.8721.0084Alnico VIIIb2.9152.8720.9852.8522.87210.0740% aCo, 7% Ti.42% bCo, 8% Ti.(4) A three dimensional periodic modulated structure is formed at an early stage of tempering with and without a magnetic field applied. As tempering time increases, modulation disappears in the direction coinciding with the external field vector. As a result of this process, a uniaxial structure of rod-shaped particles modulated along the two perpendiculars to the field is formed. The data obtained in this work confirms the spinodal nature of solid solution decomposition in Alnico alloys. II. Microstructural analysis of Alnico VS55 single crystals revealed their dendritic structure. Some segregation was observed in the lower parts of single crystals. Electron microprobe analysis of these regions showed their chemical heterogeneity. Sharp variations of titanium, copper and iron content with respect to the basic composition of the alloy were observed. Investigation of the composition variation shows strong liquation of copper and titanium with distribution coefficients K<1. The observed chemical heterogeneity is accompanied by physical heterogeneity. X-ray topography observations were made on single crystals parallel and perpendicular to the growth direction. Maximum misorientation on the end surface is 4°, while on the surface parallel to the growth direction it does not exceed 32′. The boundaries lie between the dendrite branches. The average size of subgrains is 0.2–0.7 mm. Investigation of the fine decomposition structure α→α+α′ after standard magnet heat treatment reveals places with particles having different shape anisotropy, different orientations, and even different degrees of decomposition. Work was carried out to find the influence of copper and titanium concentration on the decomposition process, and thus on the temperature of isothermal tempering in a magnetic field, and also the influence of the value of the angle between 〈100〉 axes and the direction of magnetic field during heat treatment. Thus, the single-crystal heterogeneity and permanent-magnet properties are shown. Possible ways of removing different kinds of imperfections by changing the regimes of single-crystal growth, and by adding small quantities of some alloying elements to decrease constitutional supercooling, were investigated. The maximum magnet energy of the single crystals was larger than 10·106 G–Oe, with coercive force of 2000 Oe. Both parts of this abstract will be published in the I.E.E.E. Transactions on Magnetics as individual papers.

Effect of Iron, Aluminum and Humic Acid on Phosphorus Fixation by Organic Soils

AbstractStudies were conducted comparing the effects of Fe, Al, and humic acid on P fixation in two organic soils which had undergone different degrees of decomposition. It was shown that organic soils fix P similarly to other reported P‐fixing systems. Fe and/or Al additions increased phosphate fixation while humic acid resulted in an apparent negative absorption. Further, humic acid prevented absorption of P in the presence of limited quantities of Fe and Al.