The Impact of Disturbed Soil Structure on the Degradation of Two Fungicides Under Constant and Variable Moisture

2021 ◽  
Author(s):  
Laurence H. Hand ◽  
Samantha J. Marshall ◽  
Christine Dougan ◽  
Carol Nichols ◽  
Aniko Kende ◽  
...  
Keyword(s):  
Soil Structure ◽  
Disturbed Soil ◽  
The Impact

The Semi-Active Control Considering Structure-Basement-Pile-Soil Interaction

2010 ◽  
Vol 163-167 ◽  
pp. 2780-2786
Author(s):  
Yan Tao Li ◽  
Zhan Xue Zhou
Keyword(s):  
Active Control ◽  
Structural Control ◽  
Soil Structure ◽  
Tall Buildings ◽  
Interaction System ◽  
Subdomain Method ◽  
Infinite Element Method ◽  
Fixed End ◽  
Instantaneous Optimal Control ◽  
The Impact

The interaction system which includes pi1e-supported tall buildings with multistoried basements and the adjacent medium of soil subject to the impact of earthquake is formulated in terms of the spline subdomain method,semi-analytical infinite element method and the bend-shear model of beam element,respectively.Taking advantage of the instantaneous optimal control algorithm, structure-basements-piles-soil interaction effect on the semi-active control is considered. It is shown that the results of structural control have obvious difference between the interaction system and the fixed-end system.The response of the former may be less about 10 percent than the latter in the paper.The dissipative capability of the structure self may be ignored largely if the interaction isn’t considered.When designing the system of the semi-active control, especially for some tall buildings,soil-structure interaction should be taken into consideration.

scholarly journals PROSPEK TEKNOLOGI REMEDIASI LAHAN KRITIS DENGAN ASAM HUMAT (Humic Acid)

2016 ◽  
Vol 12 (1) ◽  
pp. 55
Author(s):  
Untung Suwahyono
Keyword(s):  
Soil Structure ◽  
Agricultural Land ◽  
Green Revolution ◽  
Impact Resistance ◽  
Systemic Impact ◽  
Contamination Levels ◽  
The 19Th Century ◽  
Met Expectations ◽  
The Impact ◽  
Systemic Degradation

The green revolution in the 19th century, has met expectations in an effort to increase the productivity of food supply, in the world at least in Indonesia. In the course of time the green revolution movement has given the systemic impact not only on the degradation of ecosystems, but also the productivity of land, especially paddy fields due to the use of agrochemicals that have been over threshold. The impact on soil in Indonesia become ill, there is a change of soil structure, become poorer and finally lost as the land carrying capacity of production. Systemic Degradation covering 18 000 ha of wetland, contamination levels of heavy metals such as Hg, Fe, Cd, Cu has been on conditions that endanger human health also pesticide has an impact resistance to pests.Recovery efforts of agricultural land, will take time, and cost is not cheap. Various studies have been done, to remediation land by using acid-humic substances, and gives results quite encouraging, because it’s quite effective, efficient and inexpensive, compared with conventional methods is to provide an organic material such as kompost.

Optimal Design of NPP Containment Protection Against Fuel Container Drop

2013 ◽  
Vol 688 ◽  
pp. 213-221 ◽  
Author(s):  
Juraj Králik
Keyword(s):  
Optimal Design ◽  
Nuclear Power ◽  
Soil Structure ◽  
Integration Method ◽  
Free Fall ◽  
Dynamic Equations ◽  
Impact Loads ◽  
Building Structure ◽  
Reinforced Concrete Structure ◽  
The Impact

This paper presents a optimal design of a damping devices for the protection of the reinforced concrete structure of a nuclear power plant (NPP) against the impact loads from a container of nuclear fuel of the type TK C30 drop. The finite element idealization of the building structure is used in space. The interaction of the soil-structure, as well as the fluid-structure of the deactivated basin is considered in space. A steel pipe damper system is proposed for the dissipation of the kinetic energy of the container is free fall. The Newmark’s integration method is used for the solution of the dynamic equations.

Disentangling the impact of AM fungi versus roots on soil structure and water transport

2008 ◽  
Vol 314 (1-2) ◽  
pp. 183-196 ◽  
Author(s):  
Paul D. Hallett ◽  
Debbie S. Feeney ◽  
A. Glyn Bengough ◽  
Matthias C. Rillig ◽  
Charlie M. Scrimgeour ◽  
...  
Keyword(s):  
Water Transport ◽  
Soil Structure ◽  
Am Fungi ◽  
The Impact

Systemic modelling of soil functions under the impact of agricultural management

2020 ◽  
Author(s):  
Sara König ◽  
Ulrich Weller ◽  
Birgit Lang ◽  
Mareike Ließ ◽  
Stefanie Mayer ◽  
...  
Keyword(s):  
Soil Structure ◽  
Water Distribution ◽  
Management Strategies ◽  
Simulation Models ◽  
Crop Growth ◽  
Soil Productivity ◽  
Soil Functions ◽  
Management Options ◽  
Soil Organic Matter Turnover ◽  
The Impact

<p>The increasing demand for food and bio-energy gives need to optimize soil productivity, while securing other soil functions such as nutrient cycling and buffer capacity, carbon storage, biological activity, and water filter and storage. Mechanistic simulation models are an essential tool to fully understand and predict the complex interactions between physical, biological and chemical processes of soil with those functions, as well as the feedbacks between these functions.</p><p>We developed a systemic soil model to simulate the impact of different management options and changing climate on the named soil functions by integrating them within a simplified system. The model operates on a 1d soil profile consisting of dynamic nodes, which may represent the different soil horizons, and integrates different processes including dynamic water distribution, soil organic matter turnover, crop growth, nitrogen cycling, and root growth.</p><p>We present the main features of our model by simulating crop growth under various climatic scenarios on different soil types including management strategies affecting the soil structure. We show the relevance of soil structure for the main soil functions and discuss different model outcome variables as possible measures for these functions.</p><p>Further, we discuss ongoing model extensions, especially regarding the integration of biological processes, and possible applications.</p>

scholarly journals Assessment of Heavy Metals in Soil, Paddy Straw and SEM analysis of the soil for the impact of wastewater irrigation in Girudhumal Sub basin of Tamil Nadu, India

2018 ◽  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Contamination ◽  
Soil Structure ◽  
Heavy Metal Contamination ◽  
Sem Analysis ◽  
Wastewater Irrigation ◽  
Urban Region ◽  
Paddy Straw ◽  
The Impact

<p>The objective of the study is to determine accumulation and translocation of heavy metals from soil to paddy straw irrigated with urban sewage wastewater in peri-urban region of Girudhumal subbasin area in Madurai. The soil samples were collected in seven locations irrigated with treated and untreated wastewater and analyzed for physical properties like pH, EC, bulk density, soil type, major (N,P,K) and micronutrients (Fe, Mn, Cu, Zn) and heavy metals Ni, Cd, Pb. SEM analysis showed that soil structure is significantly influenced by wastewater irrigation. It confirms that the wastewater irrigation disturbs soil structure and affecting the plant growth in long run.&nbsp; Pb content was higher than the prescribed safe limits in S5 and S6 location, similarly, Ni also was higher than the safe limit in all the locations. Pollution Load Index values are in the range of 0.08-0.56 for all sites, and it indicated that chance of heavy metal contamination is less. The EF values show moderate enrichment to Ni and Zn, Significant enrichment for Cd and Cu, Extremely high for Pb and deficiency for Mn. All these results confirmed that there is no immediate risk of heavy metal pollution, however with respect to Pb and Ni the plant tissues are showing higher values. The transfer factor for heavy metals from soil to paddy straw is less than 0.5 for Cd and for others is more than 0.5 indicated greater chances for heavy metal contamination.</p>

scholarly journals KEYLINK: towards a more integrative soil representation for inclusion in ecosystem scale models. I. review and model concept

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9750
Author(s):  
Gaby Deckmyn ◽  
Omar Flores ◽  
Mathias Mayer ◽  
Xavier Domene ◽  
Andrea Schnepf ◽  
...  
Keyword(s):  
Food Web ◽  
Soil Structure ◽  
Soil Food Web ◽  
Ecosystem Models ◽  
Model Concept ◽  
Soil Functioning ◽  
Scale Models ◽  
Key Issues ◽  
Below Ground ◽  
The Impact

The relatively poor simulation of the below-ground processes is a severe drawback for many ecosystem models, especially when predicting responses to climate change and management. For a meaningful estimation of ecosystem production and the cycling of water, energy, nutrients and carbon, the integration of soil processes and the exchanges at the surface is crucial. It is increasingly recognized that soil biota play an important role in soil organic carbon and nutrient cycling, shaping soil structure and hydrological properties through their activity, and in water and nutrient uptake by plants through mycorrhizal processes. In this article, we review the main soil biological actors (microbiota, fauna and roots) and their effects on soil functioning. We review to what extent they have been included in soil models and propose which of them could be included in ecosystem models. We show that the model representation of the soil food web, the impact of soil ecosystem engineers on soil structure and the related effects on hydrology and soil organic matter (SOM) stabilization are key issues in improving ecosystem-scale soil representation in models. Finally, we describe a new core model concept (KEYLINK) that integrates insights from SOM models, structural models and food web models to simulate the living soil at an ecosystem scale.

scholarly journals Impact of freeze-thaw cycles on soil structure and soil hydraulic properties

2021 ◽  
Author(s):  
Frederic Leuther ◽  
Steffen Schlüter
Keyword(s):  
Pore Structure ◽  
Soil Structure ◽  
Hydraulic Properties ◽  
Initial Structure ◽  
Soil Hydraulic Properties ◽  
Pore Connectivity ◽  
Freeze Thaw ◽  
Frost Action ◽  
Soil Hydraulic ◽  
The Impact

Abstract. The ploughing of soils in autumn drastically loosens the soil structure and at the same time reduces its stability against external stresses. A fragmentation of these artificially produced soil clods during winter time is often observed in areas with air temperatures fluctuating around the freezing point. Farmers benefit from the structural transformation by frost action in terms of better seedbed preparation and improved hydraulic connectivity. Previous studies have mainly focused on the effects of freezing and thawing on soil structure stability rather than on the impact on pore structure. From the pore perspective, it is still unclear (i) under which conditions frost action has a measurable effect on soil structure, (ii) what the impact on soil hydraulic properties is, and (iii) how many freeze-thaw cycles (FTCs) are necessary to induce soil structure changes. The aim of this study was to analyse the cumulative effects of multiple FTC on soil structure and soil hydraulic properties for two different textures and two different initial structures. A silt clay with a substantial amount of swelling clay minerals and a silty loam with less swell/shrink dynamics were either kept intact in undisturbed soil cores taken from the topsoil from a grassland or repacked with soil clods taken from a ploughed field nearby. FTCs were simulated under controlled conditions and changes in pore structure ≥ 48 µm were regularly recorded using X-ray µCT. After 19 FTCs, the impact on hydraulic properties were measured and the resolution of structural characteristics were enhanced towards narrow macro-pores with subsamples scanned at 10 µm. The impact of FTC on soil structure was dependent on the initial structure, soil texture, and the number of FTCs. Frost action induced a consolidation of repacked soil clods, resulting in a systematic reduction in pore sizes and macro-pore connectivity. In contrast, the macro-pore systems of the undisturbed soils were only slightly affected. Independent of the initial structure, a fragmentation of soil clods and macro-aggregates larger than 0.8 to 1.2 mm increased the connectivity of pores smaller than 0.5 to 0.8 mm. The fragmentation increased the unsaturated hydraulic conductivity of all treatments by a factor of 3 in a pF range of 2.0 to 2.5, while water retention was only slightly affected for the silt clay soil. Already 2 to 5 FTCs enforced a well-connected meso-pore system in all treatments, but it was steadily improved by further FTCs. This steady improvement in structural quality in terms of meso-pore connectivity is put at risk by milder winters in mid-latitudes due to global warming.

scholarly journals Conditions of soils dilution of dams under seismic impacts

2021 ◽  
Vol 264 ◽  
pp. 03047
Author(s):  
Khayat Rasulov
Keyword(s):  
Soil Structure ◽  
Dynamic Pressure ◽  
Theoretical Method ◽  
The Body ◽  
Cohesive Soils ◽  
Important Indicator ◽  
Disturbed Soil ◽  
Soil Structures ◽  
Water Saturated ◽  
Seismic Impacts

This report presents the results of the author's research on the dilution of water-saturated cohesive soils in the conditions of concussions. The nature of the weakening of the soil connectivity during vibration and the dynamic pressure that occurs in the thickness during the compaction of the disturbed soil structures, which contribute to the liquefaction and spreading of the soil from the body of the structure, is described. The criterion of the possibility of violation of the soil structure in the conditions of concussions is given. A theoretical method for determining this important indicator of the seismic strength of the soil is given.

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