The effect of alfalfa age on the accumulation of total and soil organic matter when rotating grain crops

Исследования проведены в 2013–2015 годах в ООО «Вымпел 2002» в Хасавюртовском районе Республики Дагестан. Почва экспериментального участка содержит в пахотном слое гумуса 2,77%, Р2О5 — 2,21 мг, К2О — 32,8 мг/100 г почвы, плотность в пахотном слое — 1,24 г/см3, наименьшая влагоёмкость слоя 0–0,6 м — 29,2%. Целью наших исследований являлось выявление влияния возраста люцерны на накопление общей и неотчуждаемой из почвы органической массы в зернокормовом севообороте в условиях Западного Прикаспия. Рассмотрено два севооборота (с двухлетней и трёхлетней люцерной), по пласту и обороту пласта выращивали озимую пшеницу, после уборки которой в пожнивный период с помощью провокационного полива формировали пожнивный естественней фитоценоз (ПЕФ). Степень насыщения севооборотов люцерной составляла соответственно 50 и 60,0%, озимой пшеницей + ПЕФ — 60,0 и 40%. Установлено, что увеличение срока использования люцерны в зернотравяных севооборотах с 2 до 3 лет и доли её в структуре посевных площадей с 50 до 60% способствовало увеличению сборов сена с 1 га севооборотной площади на 2,57 т/га (на 19,0%), зерна озимой пшеницы по пласту — на 7,9%, по обороту пласта — на 6,5%, надземной массы ПЕФ — на 5,3 и 5,1% соответственно. Одновременно увеличивалось и количество накапливаемой растительной массы с 71,56 до 92,66 т/га севооборотной площади. Но в том случае, когда люцерна в севообороте использовалась 2 года, а доля озимой пшеницы с последующим использованием пожнивного периода под ПЕФ увеличивалась с 40 до 50% севооборотной площади, неотчуждаемой из почвы растительной массы накапливалось больше на 20,2%. Заслуживает уточнения в методическом плане вопрос об отнесении части урожая сена люцерны, произведённого в хозяйстве, к неотчуждаемой из почвы продукции подобно тому, как это делается в отношении соломы, только 60% которой считается экосистемной. The investigation took place at the OOO “Vympel 2002” in the Khasavyurt district of the Republic of Dagestan in 2013–2015. Soil of the trial field contained 2.77% of humus, Р2О5 — 2.21 mg, К2О — 32.8 mg/100 g of soil, layer density — 1.24 g/cm3, the lowest moisture content of the 0–0.6 m layer — 29.2%. The aim was to test the effect of alfalfa age on the accumulation of total and soil organic mass in grain crop rotation in the Western Caspian region. Two crop rotations were studied (two- and three-year old alfalfa). After harvesting winter wheat the plot was irrigated to form post-harvest natural phytocenosis. Alfalfa proportion amounted to 50 and 60%, winter wheat + post-harvest natural phytocenosis — 60 and 40%. Cultivation of alfalfa for 3 years instead of 2 and increase in its proportion from 50 to 60% improved hay yield by 2.57 t ha-1 (19%), wheat grain yield — by 7.9 and 6.5%, top mass of post-harvest natural phytocenosis — by 5.3 and 5.1%, respectively. Plant mass increased from 71.56 to 92.66 t ha-1. When alfalfa was cultivated for 2 years and winter wheat proportion raised from 40 to 50%, accumulation of soil organic matter improved by 20.2%. Attributing part of alfalfa hay to soil organic matter was performed the same way as for straw, only 60% of which belonged to an ecosystem.

On the use of products of the organic matter extraction from coal as a component of fuels

Extraction of the coal organic mass under the influence of organic dissolvent is a method of conversing coal into liquid products. The need for the further development of this technology is associated with the need to search for alternative direct liquefaction and gasification technologies for obtaining alternative fuel products. The paper presents the analysis results of hydrocarbon fractions 112-400 °C, obtained by joint heat treatment of coal and catalytic cracking heavy gas oil according to some quality indicators of traditional fuels. In general, according to some indicators this product is close to boiler fuels. But aromatic hydrocarbons and olefins predominate in the extraction products if we take into account chemical structure. So, it requires their hydrogenation improving.

Droplet activation of moderately surface active organic aerosol predicted with six approaches to surface activity

Surface active compounds (surfactants) found in atmospheric aerosols can decrease droplet surface tension as they adsorb to the droplet surfaces simultaneously depleting the droplet bulk. These processes may influence the activation properties of aerosols into cloud droplets and investigation of their role in cloud microphysics has been ongoing for decades. In this study, we have used six different approaches documented in the literature to represent surface activity in Köhler calculations predicting cloud droplet activation properties for particles consisting of one of three different moderately surface active organics mixed with ammonium sulphate in different ratios. We find that the different models predict comparable activation properties at small organic mass fractions in the dry particles for all three moderately surface active organics tested, even with large differences in the predicted degree of bulk-to-surface partitioning of the surface active component. However, differences between the models regarding both the predicted critical diameter and supersaturation for the same dry particle size increase with the organic fraction in the particles. Comparison with available experimental data shows that assuming complete bulk-to-surface partitioning of the organic component (total depletion of the bulk) along the full droplet growth curve does not adequately represent the activation properties of particles with high moderate surfactant mass fractions. Accounting for the surface tension depression mitigates some of the effect. Models that include the possibility for partial bulk-to-surface partitioning yield comparable results to the experimental data, even at high organic mass fractions in the particles. The study highlights the need for using thermodynamically consistent model frameworks to treat surface activity of atmospheric aerosols and for firm experimental validation of model predictions across a wide range of states relevant to the atmosphere.

Eight years of sub-micrometre organic aerosol composition data from the boreal forest characterized using a machine-learning approach

The Station for Measuring Ecosystem–Atmosphere Relations (SMEAR) II, located within the boreal forest of Finland, is a unique station in the world due to the wide range of long-term measurements tracking the Earth–atmosphere interface. In this study, we characterize the composition of organic aerosol (OA) at SMEAR II by quantifying its driving constituents. We utilize a multi-year data set of OA mass spectra measured in situ with an Aerosol Chemical Speciation Monitor (ACSM) at the station. To our knowledge, this mass spectral time series is the longest of its kind published to date. Similarly to other previously reported efforts in OA source apportionment from multi-seasonal or multi-annual data sets, we approached the OA characterization challenge through positive matrix factorization (PMF) using a rolling window approach. However, the existing methods for extracting minor OA components were found to be insufficient for our rather remote site. To overcome this issue, we tested a new statistical analysis framework. This included unsupervised feature extraction and classification stages to explore a large number of unconstrained PMF runs conducted on the measured OA mass spectra. Anchored by these results, we finally constructed a relaxed chemical mass balance (CMB) run that resolved different OA components from our observations. The presented combination of statistical tools provided a data-driven analysis methodology, which in our case achieved robust solutions with minimal subjectivity. Following the extensive statistical analyses, we were able to divide the 2012–2019 SMEAR II OA data (mass concentration interquartile range (IQR): 0.7, 1.3, and 2.6 µg m−3) into three sub-categories – low-volatility oxygenated OA (LV-OOA), semi-volatile oxygenated OA (SV-OOA), and primary OA (POA) – proving that the tested methodology was able to provide results consistent with literature. LV-OOA was the most dominant OA type (organic mass fraction IQR: 49 %, 62 %, and 73 %). The seasonal cycle of LV-OOA was bimodal, with peaks both in summer and in February. We associated the wintertime LV-OOA with anthropogenic sources and assumed biogenic influence in LV-OOA formation in summer. Through a brief trajectory analysis, we estimated summertime natural LV-OOA formation of tens of ng m−3 h−1 over the boreal forest. SV-OOA was the second highest contributor to OA mass (organic mass fraction IQR: 19 %, 31 %, and 43 %). Due to SV-OOA's clear peak in summer, we estimate biogenic processes as the main drivers in its formation. Unlike for LV-OOA, the highest SV-OOA concentrations were detected in stable summertime nocturnal surface layers. Two nearby sawmills also played a significant role in SV-OOA production as also exemplified by previous studies at SMEAR II. POA, taken as a mix of two different OA types reported previously, hydrocarbon-like OA (HOA) and biomass burning OA (BBOA), made up a minimal OA mass fraction (IQR: 2 %, 6 %, and 13 %). Notably, the quantification of POA at SMEAR II using ACSM data was not possible following existing rolling PMF methodologies. Both POA organic mass fraction and mass concentration peaked in winter. Its appearance at SMEAR II was linked to strong southerly winds. Similar wind direction and speed dependence was not observed among other OA types. The high wind speeds probably enabled the POA transport to SMEAR II from faraway sources in a relatively fresh state. In the event of slower wind speeds, POA likely evaporated and/or aged into oxidized organic aerosol before detection. The POA organic mass fraction was significantly lower than reported by aerosol mass spectrometer (AMS) measurements 2 to 4 years prior to the ACSM measurements. While the co-located long-term measurements of black carbon supported the hypothesis of higher POA loadings prior to year 2012, it is also possible that short-term (POA) pollution plumes were averaged out due to the slow time resolution of the ACSM combined with the further 3 h data averaging needed to ensure good signal-to-noise ratios (SNRs). Despite the length of the ACSM data set, we did not focus on quantifying long-term trends of POA (nor other components) due to the high sensitivity of OA composition to meteorological anomalies, the occurrence of which is likely not normally distributed over the 8-year measurement period. Due to the unique and realistic seasonal cycles and meteorology dependences of the independent OA subtypes complemented by the reasonably low degree of unexplained OA variability, we believe that the presented data analysis approach performs well. Therefore, we hope that these results encourage also other researchers possessing several-year-long time series of similar data to tackle the data analysis via similar semi- or unsupervised machine-learning approaches. This way the presented method could be further optimized and its usability explored and evaluated also in other environments.

Thermokinetic parameters of the primary coal tars destruction in the presence of catalysts and polymeric materials

The hydrogen-donor abilities of polymers and the activity of catalysts in the process of thermal destruction of the organic mass of primary coal tar (PCT) are studied by non-isothermal kinetics methods. PCT,magnetic microspheres, nickel-deposited chrysotilechrysotile and Fe3O4nanocatalysts were used as initial raw materials. Рolymers such as polyethylene (PE), polystyrene(PS) and polyethylene glycol (PEG) were selected as a hy-drogen donor. The phases Mg3[OH]4{Si2O5} and NiO were determined by X-ray phase analysis (XRD) in the obtained catalyst (nickel-deposited chrysotile), and the presence of highly dispersed nickel oxide particles on the surface and inside the nanotubes was shown by the transmission electron microscope (TEM). Nickel oxide particles of 8–11 nmand 30–37 nmwere evenly distributed on the surface and inside the chrysotile nanotubes. The kinetic parameters of the thermal destruction of a mixture of PCT, catalyst and polymer material were determined on the basis of thermogravimetric analysis using the integral method and the method for determin-ing the thermokinetic parameters by the inflection point on the thermogravimetric curve(TG). The change in the activation energy, rate constant and pre-exponential factor with an increase in the degree of destruction of the organic mass of the PCT is established. It was shown that the nature of polymers and catalysts significantly affects the value of the rate constant and the activation energy. The calculated activation energies of the thermal destruction of a mixture of coal tar with PS and PE in the presence of a catalyst (nickel-deposited chrysotile) by the first method are 47.6 kJ/mol and 40.4 kJ/mol, and by the second method are 47.3 kJ/mol and 86.5kJ/mol respectively.

MACHINE FOR SEEDER CROPS

Recently many agricultural producers have begun to take care of environmental aspects and are gradually switching to the use of organic farming elements in the cultivation of agricultural crops, which include green fertilizers - siderates. Many experts recommend cutting the green mass of green manure crops with a mower and embedding it in the surface layer of the soil as mulch. However, not all termination methods are equally effective. In particular, when passing through a field with a rotary harrow’s green manure, the circular knives have to simultaneously perform two functions: chop and embed the vegetative mass of plants, which negatively affects the depth of processing. Therefore, the goal of our research is to develop a combined unit for mowing, crushing and embedding green mass of green manure crops into the soil. To achieve this, it is proposed to attach a plant chopper to the front of the tractor, which will mow and chop the plants, and two discator batteries installed on the rear hitch of the tractor will close the chopped organic mass. To determine the efficiency of using the proposed combined unit in different regions of the Republic of Tatarstan on different soils, comparative field tests were carried out, which consisted in determining the completeness of incorporation of green mass. The value of this indicator without using the mower on the front hitch was 65%, and with mowing and chopping - 95%, this is 1.5 times more than in the version with the compared unit, which should favorably affect the decomposition of the embedded organic matter

CONTACT ANGLE OF COAL WETTING WITH WATER

It is known that in the process of coking a compacted coal charge during its ramming in an industrial ramming-loading-pushing machine, the moisture of the charge plays the role of a compaction agent. On the basis of this, the authors put forward a reasonable assumption that the higher the ability of coal grains to hydration, the stronger the contact between them and, accordingly, the greater the density of the formed rammed coal cake. Therefore, the determination of the ability to hydrate the surface of coal used in the charge for ramming is of both theoretical and practical importance. For the numerical determination of this indicator, the authors have chosen the contact angle of wetting, determined by the method of "sessile drop" of water on a carbon substrate. The article presents the results of a study of the ability of various brands of coal to hydrate. The article describes the characteristics of the studied grades of coal and their contact angle of wetting with water (Ɵ) after 1, 2 and 3 minutes of keeping the drop on a polished surface. Since according to the literature data, the organic mass of coal is hydrophobic, and mineral impurities, as a rule, are hydrophilic, the authors investigated the degree of influence of the "ash content of coal" (Аd ) indicator on the value of Ɵ. To determine the influence of the wetting angle and the internal moisture content of coal after 14 hours of moisture saturation in water (Wins) on the strength (ϭss) of the rammed sample, the corresponding graphical dependence was determined. The data obtained indicate that any significant relationship between Аd and Ɵ is absent, the correlation coefficient is insignificant (r = 0.28). Thus, the predominant factor in the hydration of cleaned coal is the properties of its organic matter. The correlation between Ɵ and the yield of volatile substances Vdaf and the content of vitrinite Vt is also insignificant – the correlation coefficient is up to 0,43 and 0,50 respectively. A close relationship of the contact angle was found with the reflection coefficient of vitrinite Ro (r = 0.72), the internal moisture content of coal after 14 hours of saturation in water, Wins (r = 0,65), and the shear strength of the rammed coal sample ϭss (r = 0,68). Keywords: coal, ability to hydration, contact angle of wetting, organic mass of coal, mineral impurities, density, strength. Corresponding author V.M. Kuznichenko, e-mail: : [email protected]

Deep processing of organic mass of finely dispersed coal waste

The technological and technical possibility of deep processing of coal by its liquefaction using the methods of extreme mechanochemical and physical effects has been determined; recommendations have been developed for the applied use of the obtained materials in heat power engineering. The organic part of the solid mass of the prepared coal-oil suspension, which has turned into a relatively heavy organic liquid, can be used as a boiler or motor fuel, as well as a feedstock for the production of various hydrocarbon liquids. The resulting mixture of hydrocarbons can be subjected to rectification to obtain hydrocarbon fractions for the production of plastics, oil fractions and the entire spectrum of hydrocarbons for secondary use. The effective use of the above substances will make it possible to obtain not only economic, but also a significant environmental effect. The possibility of liquefying the organic mass of coal using decalin as a hydrogen donor is shown. It was found that the addition of 3% decalin improves the liquefaction process during cavitation treatment. Liquefaction of the organic mass of coal is accompanied by the splitting of the structures of macromolecules of organic substances of coal into aromatic fragments with a lower molecular weight. It should be noted that the developed technology will solve the problem of increasing the value of the final coal product, including by involving unused fine coal sludge into circulation.

Characterization and Analysis of Oil Palm Empty Fruit Bunch (OPEFB) Waste of PT Kharisma Alam Persada South Borneo

Empty oil palm bunches are the largest solid waste produced from the palm oil industry processing. In processing 1 ton of fresh palm oil bunches, 230 Kg of empty palm oil bunches will be produced. Based on previous research, it is known that oil palm empty fruit bunches waste is proven to have a large amount of organic mass such as cellulose, hemicellulose, lignin. Organic content as mentioned is rich in benefits so that it can be used as raw material for making daily needs products ranging from food to complementary products such as household appliances, clothing and so on. For this reason, a study was conducted on the content of oil palm empty bunches originating from waste at PT. Kharisma Alam Persada. The characterization process was carried out using the SNI method 0128911992. From the research carried out it was found that the cellulose, hemicellulose and lignin content were 55.75%; 28.93% and 15.32% respectively. So that it is possible to be used as raw material for processing other products.