Soil Medium Research Articles

SEISMIC MITIGATION EFFECT FOR LARGE-SPACE UNDERGROUND STRUCTURES CONSIDERING SPATIALLY VARYING SOIL PROPERTIES

The seismic response of the large-space underground structure (LSUS) is significantly influenced by the physical properties of the surrounding soil media, while the soil owns a strong spatial variability. This study proposes a seismic response analysis process of the soil-LSUS interaction system is proposed, which can consider the characteristic of the spatially distributed soil properties. The proposed process begins with establishing the spatially random field model of the soil properties using the improved latent space method. Then, the model is calibrated based on the real data and Bayesian approach, and the realization of the random field is accomplished. Further, the soil-LSUS interaction finite element (FE) model is established, which incorporating the soil physical properties generated from the random field. Finally, the nonlinear time-history analysis of the soil-LSUS interaction FE model is conducted. As an illustration of the proposed process, a typical LSUS located in Guangzhou is selected as an example, and the seismic mitigation measure which the lead-filled steel tube damper (LFSTD) is installed between the intermediate column and the top beam is adopted for the LSUS. The influence of the spatial variability of soil properties on the seismic mitigation effect of the LSUS is investigated. Results indicate that the spatial variability of the soil properties can cause a minor influence on the force and deformation of the intermediate column and the energy dissipation ratio between the LFSTD and structure, while it can bring a significant influence on the maximum deformation and force and the shape of the hysteresis loop of the LFSTD.

Occurrence differences of hexachlorobutadiene and chlorobenzenes in road dust and roadside soil media in an industrial and residential mixed area in Eastern China

The road dust and roadside soil can act as both sinks and sources of hexachlorobutadiene (HCBD) and chlorobenzenes (CBzs), but comparative research on these two adjacent media is extremely limited. In this study, HCBD and CBzs were simultaneously analyzed in road dust and roadside soil samples from an area containing both industrial factories and residential communities in Eastern China. The road dust there was found to have 2–6 times higher contents of HCBD (mean 1.14 ng/g, maximum 6.44 ng/g) and ∑Cl3-Cl6CBzs (22.8 ng/g, 90.6 ng/g) than those in the roadside soil. The spatial distributions of HCBD and CBzs in road dusts were affected by various types of sources, showing no significant discrepancy among the sites. On the contrast, HCBD and CBzs contamination in roadside soils occurring near several factories were strongly correlated to their industrial point sources. Risk assessments showed, at current contamination levels in the road dust and roadside soil, HCBD and CBzs are not likely to induce carcinogenic or non-carcinogenic risks to residents in the studied area. Nevertheless, road dust ingestion, as the major exposure pathway of HCBD and CBzs, should be avoided to reduce the exposure risk. These findings based on the contamination differences between two media provide a new perspective and evidence for screening important sources and exposure pathway of HCBD and CBzs, which would be helpful to their source identification and risk control.

A Hydroponic-Based Bioassay to Facilitate Plasmodiophora brassicae Phenotyping.

Clubroot, caused by the obligate parasite Plasmodiophora brassicae, is one of the most devastating diseases affecting the canola/oilseed rape (Brassica napus) industry worldwide. Currently, the planting of clubroot-resistant (CR) cultivars is the most effective strategy used to restrict the spread and the economic losses linked to the disease. However, virulent P. brassicae isolates have been able to infect many of the currently available CR cultivars, and the options to manage the disease are becoming limited. Another challenge has been achieving consistency in evaluating host reactions to P. brassicae infection, with most bioassays conducted in soil and/or potting medium, which requires significant space and can be labor intensive. Visual scoring of clubroot symptom development can also be influenced by user bias. Here, we have developed a hydroponic bioassay using well-characterized P. brassicae single-spore isolates representative of clubroot virulence in Canada, as well as field isolates from three Canadian provinces in combination with canola inbred homozygous lines carrying resistance genetics representative of CR cultivars available to growers in Canada. To improve the efficiency and consistency of disease assessment, symptom severity scores were compared with clubroot evaluations based on the scanned root area. According to the results, this bioassay offers a reliable, less expensive, and reproducible option to evaluate P. brassicae virulence, as well as to identify which canola resistance profile(s) may be effective against particular isolates. This bioassay will contribute to the breeding of new CR canola cultivars and the identification of virulence genes in P. brassicae that could trigger resistance and that have been very elusive to this day.[Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Distribution characteristics of soil microplastics and their impact on soil physicochemical properties in agricultural areas of the North China plain.

Microplastic (MPs) pollution has become a global issue, with particular concern regarding MPs in soil. To determine the characteristics of MPs in agricultural production areas and their impact on soil physicochemical properties, soil samples were collected from different land use types in the North China Plain. Layered sampling was conducted and the soil physicochemical properties were determined. A novel image recognition method based on fluorescence staining was proposed for the batch analysis of MPs in the study area. Together with the results of the soil physicochemical properties, the impact of MPs on soil physicochemical properties was analyzed and evaluated. The results showed that the soil MPs abundance in this agricultural area was moderate to low compared to other agricultural areas, with a larger proportion of particle-type and fragment-type MPs smaller than 10 μm. The soil MPs were predominantly composed of polyvinyl chloride (PVC) and polypropylene (PP). MPs abundance was higher in farmland and forest land than in vegetable fields. The impact of MPs on soil physicochemical properties was mainly manifested in the changes in soil structure due to the different MPs characteristics. Apart from abundance, the type of MPs was found to be the main factor affecting soil bulk density, with particle size and shape influencing the soil aggregate structure. MPs may effect the pH values of sandy and loamy soils, primarily by altering the soil porosity and water holding capacity, but also by increasing the area and duration of contact between the soil medium and external water sources. This study revealed the MPs characteristics in agricultural areas as well as the pathways by which they can impact soil physicochemical properties.

Nutrition control in nutrient film technique hydroponic system using fuzzy method

Hydroponics is a method of growing crops without using soil media, instead, it utilizes water or other porous materials. The automation system is applied to control the nutrient quality of the water. Some sensors were used for measuring nutrient concentration, water level, water supply, and water volume. Temperature, TDS, and ultrasonic sensors are installed on the microcontroller for data measurement. The results of the data are processed using the Mamdani fuzzy logic method. The fuzzy logic results are used in controlling nutrition and water volume. The system can be monitored remotely with the aid of the Blynk app. The results of the automation system concluded that the desired condition reaches an average time of 13 minutes 49 seconds. Finally, the results of the fuzzy logic processing of the system have an accuracy value of 94.24% after being compared with the software simulation.

Application of DRASTIC method to identify the groundwater vulnerability to pollution in the sub-district of West Limboto and Limboto, Gorontalo Regency, Indonesia

The increment in population and agricultural sectors in West Limboto and Limboto, Gorontalo, affects the increased production of pollutants. The community uses shallow groundwater as the main water source. Since shallow groundwater is vulnerable to pollution due to community activity, this study aims to identify its vulnerability in West Limboto and Limboto. It was identified using the DRASTIC Method that will be integrated with Geographic Information System (GIS) Technique. The used parameters are Depth to Water Table, Recharge, Aquifer Media, Soil Media, Topography, Impact of Vadoze Zone, and Hydraulic Conductivity of the Aquifer. Depth to Water Table data is obtained from direct field measurement. Recharge amount data is obtained from the calculation of groundwater recharge. Aquifer Media, the Impact of Vadoze Zone, and Soil Media data are obtained from surface and subsurface geological data. Topography data is obtained from Digital Elevation Model Map. Hydraulic Conductivity is obtained from Pumping Test Data. The analysis result shows that the groundwater vulnerability of the study area was classified into 2 classes, the high index was in the southern part, and the low index was in the middle to the northern part of the study area.

Defining seismic parameters for an essential electric power facility

For the purpose of building a new electric power facility a project to determine seismic potential and seismic parameters for design is produced. Multiple in-situ geophysical investigations have been performed and soil samples have been taken to the laboratory where simple shear tests are done to determine the dynamic parameters of the soil layers. As a result, the dynamic shear modulus and damping ratio vs shear strain relationships of characteristic soil materials were defined. The response analysis was done using these curves, where the effects of the sub-surface local soil medium have a dominant influence upon the amplitude and frequency modification of the expected ground motion. Finally, the seismic design parameters, maximum accelerations at foundation level for design and maximum earthquake site-specific response spectrum have been obtained.

ІЛЕ АЛАТАУЫНДА КЕЗДЕСЕТІН SEDUM HYBRIDUM L. ЖӘНЕ SEDUM EWERSII LEDEB. ПОПУЛЯЦИЯЛАРЫНЫҢ ҚАЗІРГІ ТОПЫРАҚ ЖАҒДАЙЫ

The article describes the natural soil conditions of Sedum hybridum L. and Sedum ewersii Ledeb—populations area based on the results of field and laboratory soil studies of soils. Soil types, morphological features, chemical composition, nutrient elements, amount of humus, absorbed bases and salt composition, and mechanical composition of soils are determined. The following soil types were identified during field studies: Kokzhailau Gorge (population 1) – chernozem, Turgeni Gorge (population 2) – chernozem, near Kastek River (population 3) – chestnut soil. The humus content in the 0-80 cm layer of chernozem (population 1) of Kokzhailiau gorge is very high, ranging from 5.55-12.81%, the reaction of the soil medium is within pH 7.10-7.40, i.e. CO2 content ranges from 0.16 to 0.34. On chernozems of Turgeni gorge (population 2) humus content in 0-60 cm layer is very high, within 5.90-20.88%, reaction of soil medium within pH 6.15-7.07, amount of CO2 within 0.21-0.34. On chestnut soils near the Kastek River (population 3), the humus content in the 0-73 cm layer was in the range of 1.57-6.92%, the pH ranged from 7.13-8.23, i.e. it was alkaline, the CO2 content was in the range of 0.16 - 0.34. The composition of salts in the chernozems of the Kokzhailau gorge: CO3 - not detected; HCO3- - 0,24- 0,48 ; Cl- – 0.04; CO4- – 0,12-0,92; Sa+ – 0,29-0,49; Mg 2+ – 0,20-0,98; Na+ – 0,05-0,06; To+ – 0,05-0,23; The amount of salts is 0.060-0.083%. It was found that the soils of all 3 populations are not saline, since the amount of salts does not exceed the salinity limit.

Resistance of various soil geosystem bacteria to enzymatic lysis at different pH

Bacteria appear to be an inevitable element of soil geochemistry because they participate actively in chemical transformations of soil media components. One of the factors determining the composition of bacterial population in soil is resistance of bacteria to enzymes which hydrolyze cell walls. In the following research, resistance of bacteria (Priestia megaterium, Micrococcus luteus and Escherichia coli) to lysozyme in the pH range appropriate for soils is investigated. All the three species are proved to be most sensitive to lysozyme in slightly alkaline conditions (P. megaterium is least resistant at pH 8.0, M. luteus at pH 8.3, E. coli at pH 8.5), and resistance of all the three microorganisms in the range of pH values of 6.0—7.0 changes insignificantly. A possible factor defining the pH optimum for lysozyme activity in relation to these bacteria is the structure of negatively charged components of their cell walls and outer membranes.

Experimental and model analysis of the effect of pore and mineral characteristics on fluid transport in porous soil media

The fluid transport in porous media is a critical property for oil and gas exploitation, construction engineering, and environmental protection. It is profoundly influenced by pore geometry and mineral properties. Currently, the Kozeny–Carman equation serves as the permeability prediction equation for porous media, established on the circular pores model. However, it fails to fully account for the impact of pore shape and mineral properties of the soil, leading to significant deviations between predicted and measured soil permeability results. In this paper, based on scanning electron microscope image and mercury intrusion porosimetry, the pores were divided into circular pores and narrow slit pores according to the ratios of pore area and circumference. Then, the quantitative expression of the two types of pores and their connectivity and tortuosity were given, and the circular and narrow slit composite pore model was used to describe the soil pore. Subsequently, the electrostatic potential of pore water was calculated by the Poisson–Boltzmann equation to consider the adsorption effect of minerals on pore water. Combined with the Navier–Stokes equation, the permeability prediction equation considering pore geometry, pore connectivity, and tortuosity and mineral properties was established. Finally, the experimental results illustrated that the theoretical prediction results were in good agreement with the experimental results. The proposed permeability prediction equation proves valuable for assessing and predicting the fluid transport in porous media.

Response of different soil media combinations on shoot growth of dragon fruit cuttings

Response of different soil media combinations on shoot growth of dragon fruit cuttings

Banglaponics: A Soilless Cultivation Technique For Tomato In Bangladesh

The study was carried out to develop an efficient, reproducible method to overcome the drought stress and increasing agriculture field crisis of Bangladesh. Banglaponics, a soilless cultivation technique comprised of traditional agricultural fertilizers in pond water mixed with cow urine has been used to evaluate the efficiency of tomato production. The production rate (237.85 ± 10.87 g/plant) was significantly (p < 0.05) higher in the Banglaponics medium than soil medium. Plant height, leaf number, leaf area, root number, root length, and flower number of the studied plant showed significantly (p < 0.05) higher in Banglaponics medium than plants grown in soil. Both treatments showed that chlorophyll score and antioxidant activity (DPPH) were almost equal. Banglaponically grown plant leaf, despite having lower Ca concentrations, possessed higher concentrations of Fe and Zn than those of soil-grown. Additionally, Banglaponically grown plant also showed significantly much lower Pb concentrations than that of grown in soil. On the contrary the other two heavy metals Cr and Cd, hold nearly the same value. By appearance, Banglaponically-grown plants were much healthier than that of soil-grown. This technique can be introduced in drought-prone areas of Bangladesh as it requires much less water than soil-grown tomato plants. Bangladesh J. Bot. 52(4): 933-939, 2023 (December)

Design of a Solar Tracker for Monitoring Smart Farming Hydroponics Based on the Internet of Things

The use of Internet of Things (IoT) technology in agriculture is growing rapidly. One of the IoT technologies that can be utilized in agriculture is smart farming. Smart farming is an agricultural method that uses information and communication technology to increase productivity and efficiency in the agricultural sector, one of which is hydroponics. Hydroponics is a farming technique without using soil media, which uses water as a medium for plant growth. However, in the application of smart farming Hydroponics, some obstacles still need to be overcome. One of these obstacles is plant monitoring which is still done manually, requiring a lot of time and effort. In addition, energy use is also a problem in smart farming Hydroponics applications. One solution to these obstacles is using a solar tracker to monitor smart farming hydroponics. A solar tracker is a technology used to follow the movement of the sun to increase energy efficiency. By using a solar tracker, maximum energy can be generated, so that it can be used for monitoring smart farming hydroponics.

Pengaruh Aplikasi Biochar Tempurung Kelapa dan Pupuk Anorganik terhadap Serapan N P K dan Hasil Tanaman Jagung Manis pada Tanah Gambut

Maize (Zea may ssaccharata) is the horticulture in demand current society this. Limited avalability of land productive agriculture causes agricultural development, especially maize plant using peat soil media. Peat soil are low acidity, and nutrient content macro N, P, K available to plant also low. Attempts made for increasing the productivity of peat soils is by giving biochar and proper fertilization. Provision of biochar and inorganic fertilizer in addition to being a source of nutrients for plants, can also improve the physical, chemical and biological properties of the soil. This study aims to determine the influence of the application of coconut shell biochar and inorganic fertilizers on N P K nutrient uptake and maize crop yields. Research using Complete Random Design (CRD) factorial consists of two factors treatment and three replications. The first factor, namely coconut shell biochar which consist of 3 levels. The second factor, namely inorganic fertilizer consisting of 3 levels so there are 27 experimental units consisting of 2 sets of plants. Based on the results of variance, interaction of coconut shell biochar administration and inorganic fertilizer no significantly influence on all treatments. Whereas the administration of coconut shell biochar has no significant influence on soil pH, K uptake and cob weight, but significantly affected the wet weight, dray weight, N uptake and K uptake. Inorganik fertilizer has no significant influence on soil pH, wet weight, dry weight, N uptake and cob weight, but has a significant influence on P uptake and K uptake. The best cob weight is at A1B3 treatment (biochar coconut shell 55 gram/polybag + inorganic fertilizer 5,1 gram/polybag).

Assignment of initial parameters and boundary conditions for modeling thermal state of underground pipelines in a zone of progression of island permafrost soils

Relevance. Determined by the importance of predictive modeling of thermal state of pipeline transport facilities located in the permafrost zone. Prediction of geocryological effects is possible through computer simulation of heat and mechanical interactions between a pipeline and a soil medium. Such simulators use data on climatic and geocryological conditions and processes, as well as the information about design and process-dependent parameters of the pipeline, data on its spatial positioning. The presence of various factors influencing heat and mass transfer, as well as the complexity of their numerical simulation, can lead to incorrect design decisions. Such decisions in their turn are always associated with a loss of mechanical safety in an underground pipeline operation. To eliminate this design problem, it is necessary to correctly take into account and adopt the most relevant methods for modeling processes and soil characteristics. Aim. To conduct an analytical comparison of the results of thermal engineering calculations of one section of the route with insular permafrost in order to identify the influence of the model initial parameters on the stress-strain state of the pipeline. Methods. Analyzing the results of engineering surveys for the object of study, conducting a number of numerical calculations, and factorial comparison of the calculation results. Results. At the first stage, the authors have selected the route section of the underground pipeline corresponding to the purpose of the research, the factors influencing the results of thermal modeling. These factors will be considered in this study. At the second stage, the authors carried out modeling of 30 calculation models of one route section with a different set of input data. A factorial comparison of the effect of heat engineering calculation on the results was carried out. At the last stage, the authors carried out the strength calculations of all options for the selected section of the pipeline route as a resulting indicator of the influence of factors.

Peculiarities of using the hypothesis of S.O. Kulon for soil dispersed sediments

The publication is devoted to the outstanding French scientist Charles Auguste Coulomb, who 250 years ago (1773) proposed a hypothesis that relates tangential and normal stresses through the angle of internal friction of soils. This hypothesis provides reliable results while maintaining Hooke's law. Beyond this law, it is necessary to take into account the property of the soil medium, namely the change in volume during shearing or displacement of soils, which requires the introduction of additional dilatancy parameters.
 It is known that there are two types of friction in nature: sliding and rolling friction. At certain values of deformation in the soil medium, sliding friction, which is characterised by the traditional value of the internal friction angle, initially appears in certain zones of the soil medium at low deformations. Further increase in deformation causes rolling friction, which is characterised by a different value of the internal friction angle, almost one third less than the traditional value of the internal friction angle of the soil. This fact must be taken into account when performing numerical modelling of a dispersed soil medium from the beginning of loading to its failure. In this publication, we discuss the methodology for finding the parameters of the dilatancy theory to reveal the elastic-plastic deformation of cohesionless soils based on experimental results. Recommendations are given on the use of the Coulomb hypothesis in engineering calculations and on the relationship between tangential and normal stresses through the angle of internal friction of soils. For a correct description of the nonlinear process of soil deformation, it is necessary to use the parameters of the dilatancy theory, which can be investigated on an axisymmetric shear tester.
 The results of tests of sand of medium size, medium density, low-moisture, homogeneous on several devices showed that the values of the angle of internal friction of soils differ depending on the design of the device. This fact is recommended to be taken into account when designing geotechnical facilities.

Experiment and Simulation of Groundwater Salt Transport Based on Different Contact Relations in Heterogeneous Soil Layers

With the expansion of reserve cultivated land resources in coastal saline–alkali areas, the problem of soil salinization is becoming more and more prominent. In order to reveal the influence of different soil media and contact modes on soil water movement, a two-domain Hydrus-3D model was established to verify its performance in heterogeneous soil layers, and the characteristics of water, salt, and wet peak transport of surface soil and sandy soil under horizontal contact and inclined contact conditions were analyzed through experiments and simulations. The measured data show that in horizontal contact mode, probe 3 and probe 2 are close to the interface of the two layers of soil, and their maximum values are measured in about 60 min. The time difference between probe 1 and probe 2 is about 15 min. In the inclined contact mode, probe 4 in the topsoil reached 45% in 10 min and remained stable; the peak lag time of probes 3 and 2 was 10 min, and the peak lag time of probes 2 and 1 was 15 min; the water in the surface soil gradually increases and then stabilizes; and the water in the sand soil is similar to the normal curve. The salt characteristics in the surface soil are similar to the normal curve, while the salt characteristics in the sandy soil gradually increase and then stabilize. The simulation results show that the water content in the topsoil is more than 40%, and the maximum water content in the center of the sand is only 36.9%, which is roughly the same as the experimental results. The results showed that the Hydrus-3D model had a good simulation effect on the groundwater salt transport of heterogeneous soil under two contact methods. The RMSE value and E value are close to 0 and 1, respectively, indicating that the simulation has good feasibility and can be applied to the simulation of water and salt transport processes under different contact modes of soil media.

Modelling Groundwater Vulnerability to Contamination using DRASTIC Model through Geospatial Techniques over Northern Kwazulu-Natal, South Africa

This study models groundwater vulnerability to contamination in three northern district municipalities (Amajuba, Zululand and Umkhanyakude) in KwaZulu Natal province in South Africa using GIS-based DRASTIC model. The method considers seven parameters: depth to water table (D), recharge (R), aquifer media (A), soil media (S), topography (T), impact of the vadose zone (I), and hydraulic conductivity (C). DRASTIC parameter maps are generated in ArcGIS environment and relevant weights assigned. A weighted overlay analysis is then employed to generate the groundwater vulnerability map for the study area. Finally, the groundwater vulnerability map is combined with land use/cover to obtain groundwater pollution risk map. Results indicate that 22, 45, 21 and 12% of the total area are under low, moderate, high, and very high groundwater contamination vulnerable zones, respectively. Low, moderate, high, and very high groundwater pollution risk are found in 23, 40, 27 and 10% of the total area, respectively. These results can be used by environmental managers, spatial planers and other policy makers in formulating integrated and sustainable development plans to ensure optimal groundwater exploitation and conservation in the northern KwaZulu Natal region.

Evaluation of Soil Structure Interaction Effects on Seismic Response of RC Framed Buildings Using Simplified Method

In the current practice for the design of the building structure is done by considering the footing as fixed based. The mid-rise buildings having variation in storey height from 3- to 10-storey were selected for the research. In this research, analysis was done to study into the interaction between the seismic response of RC-framed buildings and the soil-structure for various soil types. To study the linear responses of the structures, the model was developed in FEM software SAP2000. The underneath soil was modelled by using direct method, where the soil is considered as solid element. The considered depth of soil was considered 30 m and the viscous spring dashpot were applied to avoid the reflection of seismic waves in soil medium along the effective horizontal soil boundaries. The seismic response variables such as maximum lateral deflection, inter-storey drift and fundamental time periods have been studied. SSI amplified the lateral deflection, inter-storey drift and time period of structure shifting the performance level from life safety to near collapse level. Fundamental time period of the first mode was increased by 23 % for very soft soil. The maximum lateral deflection of 10-storey building for very soft soil was amplified up to 282 % for Kobe and the performance level was shifted from life safety (1.5 %) to collapse level for all the considered model for soil type D . The performance level of structure was checked against the different soil types on varying storey height and finally a simplified method has been proposed to incorporate the effects of SSI in fixed base structures.

Implementation of Lora and CoAP Protocol in Hydroponic Plant Water Pump Control

Hydroponics is the cultivation of plants without using soil media, but using water media that contains nutrients and minerals. To observe the growth parameters of hydroponic plants, it is still necessary to come directly to the hydroponic site and provide the nutrients needed manually. In time efficiency, the use of Internet of Things (IoT) is needed so that there is no need to come directly to the hydroponic site. LoRa is a Low Power Wide Area Network (LPWAN) communication system. This research uses sensor nodes, middleware, and client nodes as well as the Constrained Application Protocol (CoAP) protocol for clients to access the value of sensors to control automatic pumps so that nutrients for plants can be given directly without the need to come to the hydroponic site. The result of the implementation is that the water pump control can run properly until the plants can be harvested. The performance testing is done so that LoRa can transmit data at a distance of 1 km with an RSSI value of -114 dBm.