MPM–FEM hybrid method for granular mass–water interaction problems

The present study proposes an MPM (material point method)–FEM (finite element method) hybrid analysis method for simulating granular mass–water interaction problems, in which the granular mass causes dynamic motion of the surrounding water. While the MPM is applied to the solid (soil) phase whose motion is suitably represented by Lagrangian description, the FEM is applied to the fluid (water) phase that is adapted for Eulerian description. Also, the phase-field approach is employed to capture the free surface. After the accuracy of the proposed method is tested by comparing the results to some analytical solutions of the consolidation theory, several numerical examples are presented to demonstrate its capability in simulating fluid motions induced by granular mass movements.

Radiocaesium retention in bog meadows: an analysis based on soil properties

<p>The deposition of large amounts of radiocaesium from the Chernobyl Nuclear Power Plant accident (ChNPP,1986) has required a study of the fate of this long-lived radioisotope in ecosystems. Fallout radionuclide becomes incorporated into the soil biogeochemical processes and the human food chain. Usually, meadows located on polluted peat soils are intensively used for sheep and cow grazing, which results in contaminated animal products. Therefore, to suggest remediation methods for contaminated bog meadows it is necessary to find out the key factors affecting the <sup>137</sup>Cs mobility in bog soils.</p><p>The vertical distribution of <sup>137</sup>Cs in peat bog soils in the remote period after the Chernobyl accident was investigated. The study was conducted on bog meadows in the Bryansk region of Russia. Soil samples were taken at locations on lowland and transitional bogs.</p><p>Fifteen years after the accident, an analysis of soils showed that the peak of <sup>137</sup>Cs activity was still in the upper 10 cm layer. This layer is usually saturated with plant roots. The highest <sup>137</sup>Cs retention (92% of the total inventory) has been observed in the top 10 cm layer in the drained bog. The findings revealed that elevated soil moisture promotes <sup>137</sup>Cs downward migration.</p><p>The rate of <sup>137</sup>Cs migration is controlled by the solid-liquid distribution coefficient K<sub>d</sub> which is related to the presence of clay minerals and cations competing for exchange sites on solid soil, such as K<sup>+</sup> and NH<sub>4</sub><sup>+</sup>. In wetlands with the high content of decomposed organic matter are created the conditions for intensive ammonification. This study provides evidence that ammonium is the major contributing factor for K<sub>d</sub> values in peat soils on bog meadows.</p><p>Remediation methods aimed at enhanced removal of <sup>137</sup>Cs from the root zone in bog soils are discussed.</p><p> </p><p> </p><p> </p><p> </p>

Structural adaptations of bovine ungulates modern agrocenosis

The article presents the results of studies of anatomical, histological and morphometric characteristics of bovine ungulates aimed at identifying signs of structural adaptation of the distal part of the limb to anthropogenically modeled content conditions. The factors that the hoof experiences are the predominance of static load, the high weight of the animal, and the support on solid soil. As a morphological control, elk is considered as a parrotfish animal with similar body size and weight, located in the conditions of natural biotsenose and moving on forest soils. It is shown that constant presence of cattle in conditions of hypokinesia on hard floors leads to change of limb setting and change of hoof shape, which is reflected in change of hoof shape, increase of hoof angle, ratio of plantar and dorsal hoof surfaces length. At the same time, the biomechanical load is redistributed between parts of the hoof so that the load on the wall increases and on the ball decreases. This may be a factor predisposing the hoof to the appearance of microtraumas, later manifested by laminites.

Potassium Mobility Potential of Forest Soil In Kurdistan Region, Iraq, As Estimated By Quantity- Intensity (Q/I) Relationships

This study aimed to assess potassium(K) 's potential mobility for some soils located in the Kurdistan Region of Iraq. Five soil samples were collected from a depth of (0-30) cm. For each sample, 5g of soil was equilibrated with 50 ml of 0.01 M CaCl2, amended with different K concentrations, and incubated for 24 h at 298 Kelvin. The supernatant was filtered, and K, Ca, and Mg were determined. Potassium exchange equilibrium was calculated from quantity-intensity (Q/I) isotherms. Mean AReK values for all studied soils ranged between 2.4x10-3 to 3.6x10-3(mol L-1)1/2, which reveals that K was preferentially held at inner potions. The amount of labile K(KL) ranged from 0.479 to 1.191cmolc kg-1 in studied soils. The highest value of KL was in Kanypanka while the lowest value was in Goizha. The potential buffering capacity (PBCK) was between 619.56 and 857.37 cmolc kg-1(mol L-1) -1/2. All studied soils were characterized by low percent K saturation and a high ability to replenish K concentration in the soil solution. Gapon selectivity coefficient was relatively high and ranged from 5.64 to 7.88 L mol-1. Higher values of KL indicate a greater K release into the soil solution. Such a high affinity of K to the solid soil phase was attributed to both the elevated organic matter content in these soils and their strong buffering capacities.

Modeling the effect of skidded timber bunches on forest soil compaction

An increasing demand for forest products incites a large number of log transportation operations, which may lead to negative consequences for the soil and the ecosystem as a whole. This paper presents a mathematical model to estimate the soil deformation and compaction processes under the influence of individual components of the skidding system, such as the forwarder, limbs, butts, and tops of tree-lengths in high latitudes, permafrost soil, and forests of the cryolithic zone. The effectiveness of the proposed model was evaluated according to experimental results. Comparative analysis showed that the calculated data differ from the experimental data by no more than 10%. The deformation of the soil by the bunch of tree-length logs occurs due to shearing processes. It has been established that the initial vertical stress exceeds the radial stress by 30–40%. The result of estimating the dependency of the shelterbelt width on the number of tree-length logs showed that the limit values for logs amount to 4–6 units for the mild, medium, and solid soil categories. The obtained results and the developed model will allow for a qualitative and quantitative assessment of the technological impact on the soil during the projecting of maps for logging operations.

Features Of Influence Of Industrial Enterprises Almalyk City On The Geological Environment

The article considers that the course of more than 5 decades as a result of the infiltration of contaminated waters of open pits, dumps, slag accumulators of the copper smelting plant (CSP), the production association (PА) "Ammophos", tailing dumps of copper concentrating factories (СCF -1 and СCF -2), as well as due to the leakage of reagents from the sulfuric acid shop through rocks that are not consistent in area and insignificant thickness of loess-like loams, and the penetration of polluting components into the aquifer occurs. Due to the action of the infiltration flow, a change in the chemical composition of soils occurs on solid soil particles, a number of chemical compounds are sorbed. The article provides recommendations for reducing the pollution of the geological environment.

Utilizing renewable resources – converting geothermal energy to electricity

According to the official definition, approved by the European Geothermal Energy Council (EGEC), geothermal energy is energy accumulated as heat below the surface of solid soil. Geothermal energy is thermal energy generated and stored in the Earth. It is generally defined as the part of geothermal heat that can be directly utilized as heat or converted into other types of energy. Geothermal resources vary by location and depth towards the Earth's core. Their use is possible for different purposes depending on their temperature. This paper presents the harnessing geothermal resources for electricity generation. There are three main types of geothermal power plants: dry steam plants, flash steam plants, and binary cycle plants. Dry steam plants pipe hot steam from underground into turbines, which powers the generator to provide electricity. Flash steam plants pump hot water from underground into a cooler flash tank. The formed steam powers the electricity generator. Binary cycle plants pump hot water from underground through a heat exchanger that heats a second liquid to transform it into steam, which powers the generator. In all mentioned systems the used fluids are recycled. It can be concluded that geothermal power plants work similarly to other power plants, but providing the steam for starting the turbine from the earth's interior. The fact that used fluids return to the ground makes geothermal energy resources renewable.

EFEK KOMPOSISI BEBERAPA MEDIA TANAM TERHADAP PERTUMBUHAN DAN PRODUKSI TANAMAN CABAI RAWIT (Capsicum frutescens L.)

This study aims to determine the composition effect of several growing media on the growth and production of cayenne pepper (Capsicum frutescens L). This research was carried out on the Labuhanbatu STIPER trial field, Jln. Manunggal AMD, Bakaran Batu Village, Rantau Selatan District, Labuhanbatu Regency, North Sumatra Province which began from December 2018 to March 2019. The experimental design used was Non Factorial Randomized Block Design (RBD) and each treatment was repeated 3 (three) times. Treatment consists of: P0 = Land (control), P1 = Solid + Land (1: 3), P2 = Cow Manure + Soil (1: 3), P3 = Sand + Soil (1: 3), P4 = Land + Solid + Cow Manure (2: 1: 1), P5 = Land + Solid + Sand (2: 1: 1), P6 = Soil + Cow Manure + Sand (2: 1: 1), P7 = Land + Solid + Cow + Sand Manure (1: 1: 1: 1). The results showed that the composition of solid + soil planting media with a ratio of 1: 3 (P1) can increase plant height, number of leaves and stem diameter of cayenne pepper plants. In the composition of soil + solid planting media + cow manure with a ratio of 2: 1: 1 (P4) can increase the weight of fruit crops and the number of fruit crops in cayenne pepper plants.Keywords: composition of planting media, cayenne pepper (Capsicum frutescens L).