scholarly journals On the Issue of Establishing the Stages of Coal Metamorphism for Predicting the Hazardous Properties of Coal Seams

Author(s):  
M.I. Antoshchenko ◽  
V.Y. Tarasov ◽  
Ye.S. Rudniev ◽  
O.I. Zakharova

The characteristic stages of metamorphic transformations of mines are established according to the increase in the elemental content of carbon and changes in other components of organic matter. Stages of metamorphism transformations with an average carbon content of more than 93.6% can significantly differ in properties due to the unpredictability of the ratio between the components of organic matter. At these stages, even a minimal difference between the components can be the reason for the emergence of new properties of the coal seams. As the influence of the processes of metamorphism increases, the boundaries of the stages, determined by the percentage of carbon, narrow. The established stages of the transformation of reservoirs in terms of the individual proportion of the components in carbonization practically do not differ from the boundaries of the stages determined by the elemental composition of organic matter. It is noted that the average carbon content at the stages of seam metamorphism, determined by the yield of coke, in most cases does not coincide with the ranges of changes in the average carbon content, established by the individual content of the components or their share in carbonization. The inconsistency of the boundaries in the stages of seam metamorphism makes it unacceptable to use the coke yield as the main criterion for assessing the conversion of coal and even more so the manifestation of hazardous properties of coal seams.

2021 ◽  
Vol 13 (2) ◽  
pp. 890
Author(s):  
Jie Zhang ◽  
Yaojun Liu ◽  
Taihui Zheng ◽  
Xiaomin Zhao ◽  
Hongguang Liu ◽  
...  

Sloping farmland is prevalent in hilly red soil areas of South China. Improper tillage patterns induce decreased soil organic matter, soil aggregate breakdown, and nutrient imbalance, thereby restricting crop production. However, the stoichiometric characteristics could reflect the nutrient availability which was mostly studied on bulk soil. The stoichiometric characteristics of soil aggregates with multiple functions in farmlands has rarely been studied. The study was to reveal the impact of tillage patterns on the size distribution, nutrient levels, and stoichiometric ratios of soil aggregates after 20 years’ cultivation. Soil samples of 0–20 cm and 20–40 cm from five tillage patterns, bare-land control (BL), longitudinal-ridge tillage (LR), conventional tillage + straw mulching (CS), cross-ridge tillage (CR), and longitudinal-ridge tillage + hedgerows (LH) were collected. The elemental content (C, N and P) and soil aggregate size distribution were determined, and the stoichiometric ratios were subsequently calculated. Through our analysis and study, it was found that the nutrient content of >2 mm soil aggregates in all plots was the highest. In the hedgerow plots, >2 mm water-stable soil aggregate content was increased. Therefore, LH plots have the highest content of organic matter and nutrients. After 20 years of cultivation, stoichiometric ratio of each plot showed different changes on soil aggregates at different levels. the C:N, C:P, and N:P ratios are lower than the national average of cultivated land. Among of them, the stoichiometric ratio in the LH plot is closer to the mean and showed better water-stable aggregate enhancement. Therefore, longitudinal-ridge tillage + hedgerows can be recommended as a cultivation measure. This study provides a reference for determining appropriate tillage measures, balancing nutrient ratios, and implementing rational fertilization.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander Zherebker ◽  
Yury Kostyukevich ◽  
Dmitry S. Volkov ◽  
Ratibor G. Chumakov ◽  
Lukas Friederici ◽  
...  

AbstractDespite broad application of different analytical techniques for studies on organic matter of chondrite meteorites, information about composition and structure of individual compounds is still very limited due to extreme molecular diversity of extraterrestrial organic matter. Here we present the first application of isotopic exchange assisted Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) for analysis of alkali extractable fraction of insoluble organic matter (IOM) of the Murchison and Allende meteorites. This allowed us to determine the individual S-containing ions with different types of sulfur atoms in IOM. Thiols, thiophenes, sulfoxides, sulfonyls and sulfonates were identified in both samples but with different proportions, which contribution corroborated with the hydrothermal and thermal history of the meteorites. The results were supported by XPS and thermogravimetric analysis coupled to FTICR MS. The latter was applied for the first time for analysis of chondritic IOM. To emphasize the peculiar extraterrestrial origin of IOM we have compared it with coal kerogen, which is characterized by the comparable complexity of molecular composition but its aromatic nature and low oxygen content can be ascribed almost exclusively to degradation of biomacromolecules.


1986 ◽  
Vol 83 (1) ◽  
pp. 77-87 ◽  
Author(s):  
M.D. Kendall ◽  
A. Warley

Mast cell granules were examined by fully quantitative X-ray microanalysis of 20 cells in freeze-dried cryosections. The mast cells were situated mainly in the connective tissue of the thymic capsule of five adult male Carworth Sprague Europe rats. In addition 30 red blood cells were analysed from the same sections. Nineteen of the mast cells had granules rich in S and K. One cell had smaller granules, and in this cell the granules contained high [Ca] and [P] instead of high [S] and [K]. In the majority of cells (13) the S:K ratio was highly correlated and less than 2.2, whereas in the remaining six cells the individual granule ratios were very variable in any one cell and much higher. The mean granule [K] (994 +/− 57 mmol kg-1 dry wt) was about four times the mean cytoplasmic level of 227 +/− 81 mmol kg-1 dry wt. The existence of this difference in concentration between the granules and the cytoplasm suggests that the K in the granules must be bound. The relationship between the [K] and [S] is discussed with regard to the possible binding of heparin and amines in the granules.


1998 ◽  
Vol 1998 ◽  
pp. 69-69
Author(s):  
S. Fakhri ◽  
A. R. Moss ◽  
D.I. Givens ◽  
E. Owen

The gas production (GP) technique has previously been used to estimate the gas volume (fermentable energy (FE)) of compound feed ingredients for ruminants (Newbold et al., 1996). It was shown that the FE content of feed mixtures was represented by the combination of the total gas from the incubation of the individual feeds. However this additivity might not be consistent throughout the incubation period. The objectives were to test whether 1. other GP parameters give better estimates of FE for simple mixtures and are they additive; 2. whether organic matter apparently degraded in the rumen (OMADR) explain differences in GP; and 3. to find out if there are any other better measures than OMADR for estimating FE.


Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2249
Author(s):  
Nikolett Uzinger ◽  
Orsolya Szécsy ◽  
Nóra Szűcs-Vásárhelyi ◽  
István Padra ◽  
Dániel Benjámin Sándor ◽  
...  

Organic waste and the compost and vermicompost derived from it may have different agronomic values, but little work is available on this aspect of sewage sludge. A 75-day pot experiment with perennial ryegrass (Lolium perenne) as the test plant aimed to investigate the fertiliser value and organic matter replenishment capacity of digested sewage sludge (DS) and the compost (COM) and vermicompost (VC) made from it, applied in 1% and 3% doses on acidic sand and calcareous loam. The NPK content and availability, changes in organic carbon content and plant biomass, and the efficiency of the amendments as nitrogen fertilisers were investigated. The final average residual carbon content for DS, COM, and VC was 35 ± 34, 85 ± 46, and 55 ± 46%, respectively. The organic carbon mineralisation rate depended on the soil type. The additives induced significant N mineralisation in both soils: the average increment in mineral N content was 1.7 times the total added N on acidic sand and 4.2 times it on calcareous loam for the 1% dose. The agronomic efficiency of COM and VC as fertilisers was lower than that of DS. In the short term, DS proved to be the best fertiliser, while COM was the best for organic matter replenishment.


2020 ◽  
Vol 23 (3) ◽  
pp. 117-124
Author(s):  
Dušan Šrank ◽  
Vladimír Šimanský

The effort to achieve the sustainable farming system in arable soil led to the intensive search for a new solution but an inspiration can also be found in the application of traditional methods of soil fertility improvement as it is shown in numerous examples in history. Recently many scientific teams have focused their attention on the evaluation of biochar effects on soil properties and crop yields. Since there are a lot of knowledge gaps, especially in explanations how biochar can affect soil organic matter (SOM) and humus substances, we aimed this study at the solution of these questions. Therefore, the objective of the experiment was to evaluate the impact of two biochar substrates (B1 – biochar blended with sheep manure, and B2 – biochar blended with sheep manure and the residue from the biogas station) at two rates (10 and 20 t ha-1) applied alone or in combination with mineral fertilizers (Urea was applied in 2018, at rate 100 kg ha-1, and Urea at rate 100 kg ha-1 + AMOFOS NP 12-52 at 100 kg ha-1 were applied in 2019) on the quantity and quality of SOM and humus of sandy soil (Arenosol, Dolná Streda, Slovakia). The results showed that application of the biochar substrates together with mineral fertilizers (MF) had more pronounced effect on the organic matter mineralization in the sandy soil which resulted in low accumulation of soil organic carbon (Corg) and labile carbon compared to biochar substrates treatments without MF. The share of humic substances in Corg significantly decreased by 16, 50, 16 and 24% in B1 at 10 t ha-1, B1 at 20 t ha-1, B2 at 10 t ha-1 and B2 at 20 t ha-1 treatments, respectively, compared to the control. A similar tendency was observed for biochar substrates treatments + MF, compared to MF control. The carbon content of humic substances (CHS) was equal to 4.40 – 5.80 g kg-1 and the biochar substrates had statistically significant influence on CHS content. On average, there was a smaller decrease of CHS in B1 at rate 10 t ha-1 than at rate 20 t ha-1 and no effect of B2 compared to control. The carbon content of fulvic acid (CFA) was 9% higher in B1 at 10 t ha-1, and 20 t ha-1, 47% higher in B2 at 10 t ha-1 and 17% higher in B2 at 20 t ha-1 compared to control. As a result of biochar substrates + MF application, the reduction in CFA was observed. The results showed a decrease of CHA : CFA ratio with association to biochar substrates alone application compared to control on one hand, and a wider of CHA : CFA ratio in biochar substrates + MF treatments in comparison to MF control on the other hand. Humus stability was increased in biochar substrates alone treatments compared to control, on the other hand, compared to MF control, the application of biochar substrates + MF resulted in a lower humus stability.


1980 ◽  
Vol 60 (2) ◽  
pp. 219-229 ◽  
Author(s):  
L. E. LOWE

Humus fraction distribution in a wide range of horizon samples was examined by measuring carbon content in humic acid (Ch), in fulvic acid (Cf) and in the strongly colored polyphenolic component of the fulvic acid fraction (Ca). Fraction distribution was described by the ratios Ch/Cf and Ca/Cf. It was concluded that humus fraction ratios were related to horizon types as used in the Canadian System of Soil Classification, and were effective in discriminating between certain horizon types, particularly between Luvisolic Bt and Podzolic Bf. The results also suggested that humus fraction ratios may be effective in separating distinct sub-populations within Ah horizons and Bf horizons in general, based on qualitative differences in organic matter present. Aspects of the role of humus fractions in soil genesis are discussed.


2021 ◽  
Vol 14 (Supl. 2) ◽  
pp. 1-8
Author(s):  
Thiago Cardoso Silva ◽  
Emmanoella Costa Guaraná Araujo ◽  
Carlos Roberto Sanquetta ◽  
José Benjamin Machado Coelho ◽  
Egídio Bezerra Neto ◽  
...  

New procedures seek to subsidize studies on biomass and carbon in forests and wood, mainly of tropical species. Thus, the work aimed to compare four methods of carbon determination in wood. A pre-dried sample of tropical wood was prepared and previously ground. In this sample, the carbon content was determined, applying four different methodologies, namely: conversion of organic matter, volumetric method, colorimetric method and dry combustion (LECO). The Tukey test was performed to determine the difference between the carbon levels obtained by each method. As a result, all methods differed statistically from each other: the colorimetric method underestimated the levels of organic carbon in a tropical wood; although widely used, the volumetric method has become obsolete; and the organic matter conversion method requires specific conversion factors for each material. So, from the environmental point of view and accuracy in obtaining data, the dry combustion method, in addition to being the closest to the standard, is also the one that generates less waste, being the most suitable to determinate carbon in wood.


2015 ◽  
Vol 72 (7) ◽  
pp. 1234-1242 ◽  
Author(s):  
K. Wada ◽  
N. Takei ◽  
T. Sato ◽  
H. Tsuno

This study aims to explore the influential sources of organic matter in first flush runoff from urban roadways by comparing organic carbon content and particle size distribution in road dust with those from discharge from vehicles during rainfall. Samples on first flush runoff and road dust were collected from urban roadways. In addition, vehicle drainage was assumed to flow from vehicles during rainfall events, so vehicle wash-off water was collected by spraying water onto the top and from the underside of vehicles to simulate accumulation during a vehicle run. In road dust, the organic carbon content in the <0.2 mm fraction was about twice that of the 0.2–2 mm fraction. The particle size distributions of both first flush runoff and vehicle wash-off water were similar, and particles <0.2 mm contributed to over 95% of the total volume. The dissolved organic carbon concentration in the vehicle wash-off water was considerably higher than that in the road dust/water mixture. The total organic carbon content in road dust was positively correlated with annual daily traffic. Therefore, vehicles were thought to strongly influence the nature of road dust.


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