The Research on the Impulse Characteristics of the Extended Grounding Electrode in the Layered Soil

2014 ◽  
Vol 615 ◽  
pp. 66-73
Author(s):  
Jun Jie Zheng ◽  
Bin Cao ◽  
Ming Liu ◽  
Chang Zheng Xia ◽  
Chang Geng Tu ◽  
...  
Keyword(s):  
Double Layer ◽  
Soil Structure ◽  
Single Layer ◽  
Layered Soil ◽  
Soil Resistivity ◽  
Grounding Resistance ◽  
Low Resistivity ◽  
High Soil ◽  
Grounding Electrode ◽  
Impulse Characteristics

The composition of the tower's grounding system is always with several layers, for single-layer structure of the tower in high soil resistivity area, it is the use of partial replacement of soil to reduce the tower grounding resistance, also the analysis object is equivalent to the hierarchical model, Therefore, the study of layered soil structure tower grounding impulse characteristics is more representative. To study the impact properties of the layered structure of the soil grounding, In this paper, through the establishment a double-layer soil model structure, the impulse characteristics of the soil structure of grounding electrode is studied through simulation, resulting of the quantitative relationship between several high resistivity soils partially replacing low resistivity soil area size and impulse grounding resistance of elongation grounding. The results show that the impulse grounding resistance decreases as the replacement area of low resistivity soil increases and converges to a certain value, which indicates the impulse characteristics of extended grounding electrode in double-layer soil model increases with the expand of the upper level low resistivity zone and approaching that of single layer with low resistivity soil. The results have a reference value for use of local soil replacement method to reduce tower impulse grounding resistance in high soil resistivity areas and the determination of soil replacement plan.

Grounding Pit Optimization Using Low Resistivity Materials for Applications in High Resistivity Soils

2011 ◽  
Vol 12 (1) ◽  
Author(s):  
Abdulrehman Ali Al-Arainy ◽  
Nazar Hussain Malik ◽  
Muhammad Iqbal Qureshi ◽  
Yasink Khan
Keyword(s):  
Power System ◽  
High Resistivity ◽  
Soil Resistivity ◽  
Operating Personnel ◽  
Grounding System ◽  
Grounding Resistance ◽  
Low Resistivity ◽  
Desert Areas ◽  
Arid Desert ◽  
Pit Design

Grounding arrangement is very important to maintain safe and reliable operation of a power system and to ensure safety of the power apparatus and operating personnel. In Saudi Arabia, the weather is dry and the soil resistivity varies significantly from area to area because the geodetic terrain varies from sea shore to the arid desert and dry mountains. In most of the inland desert areas, the soil resistivity is significantly high and it is difficult to get low earth resistance with conventional methods. Therefore, an economical and efficient grounding system design of the earthing pit is necessary which can be achieved by using a low resistivity material (LRM). When such material is used, it is important to optimize the pit design. This paper presents different configurations of grounding pits commonly used with LRM applications. Different parameters that affect the grounding resistance are studied in detail and an optimized pit design is suggested that can effectively reduce the grounding resistance to an acceptable value. The suggested method can be readily used by engineers to obtain a good earthing pit configuration for efficient grounding of the power system components in high resistivity soils.

scholarly journals Innovative earthing systems for electric power substations using conductive nanoparticles

2021 ◽  
Vol 11 (3) ◽  
pp. 1857
Author(s):  
Ahmed Thabet ◽  
Youssef Mobarak
Keyword(s):  
Power System ◽  
Comparative Study ◽  
Electric Power ◽  
Soil Resistivity ◽  
Grounding System ◽  
Grounding Resistance ◽  
High Soil ◽  
Earthing Systems ◽  
Power Substations

The earthing system is very important to safe human’s lives and protect power system from normal and abnormal faults. High soil resistivity regions is the main problem of installation the earthing systems in electric power substations to pass the current through the earth's surface. This paper has been overcome on high soil resistivity regions by penetrating conductive nanoparticles to have extremely low grounding resistance. Moreover, it has been succeeded to examine the methodology of the proposed Nano-Tech earthing systems in case of single rods, multiple rods and grids. Also, it has been defined optimal types and concentrations of nanoparticles for Nano-Tech grounding system to provide excellence protection for electrical substations with respect to built beneath of soil where substation is located. A comparative study has been discussed and analyzed the results of traditional and nanotechnology grounding systems.

Cracking at the fold in double layer coated paper: the influence of latex and starch composition

TAPPI Journal ◽  
2019 ◽  
Vol 18 (2) ◽  
pp. 93-99
Author(s):  
SEYYED MOHAMMAD HASHEMI NAJAFI ◽  
DOUGLAS BOUSFIELD, ◽  
MEHDI TAJVIDI
Keyword(s):  
Mechanical Properties ◽  
Double Layer ◽  
Starch Content ◽  
Single Layer ◽  
Double Layers ◽  
Coated Paper ◽  
Coated Papers ◽  
Coating Layers ◽  
Scanned Images ◽  
Packaging Paper

Cracking at the fold of publication and packaging paper grades is a serious problem that can lead to rejection of product. Recent work has revealed some basic mechanisms and the influence of various parameters on the extent of crack area, but no studies are reported using coating layers with known mechanical properties, especially for double-coated systems. In this study, coating layers with different and known mechanical properties were used to characterize crack formation during folding. The coating formulations were applied on two different basis weight papers, and the coated papers were folded. The binder systems in these formulations were different combinations of a styrene-butadiene latex and mixtures of latex and starch for two different pigment volume concentrations (PVC). Both types of papers were coated with single and double layers. The folded area was scanned with a high-resolution scanner while the samples were kept at their folded angle. The scanned images were analyzed within a constant area. The crack areas were reported for different types of papers, binder system and PVC values. As PVC, starch content, and paper basis weight increased, the crack area increased. Double layer coated papers with high PVC and high starch content at the top layer had more cracks in comparison with a single layer coated paper, but when the PVC of the top layer was low, cracking area decreased. No measurable cracking was observed when the top layer was formulated with a 100% latex layer.

Single layer versus double layer suture for anastomosis of the gastrointestinal tract

2009 ◽  
Author(s):  
Alvaro Sanabria ◽  
Gabriel Gomez ◽  
Eduardo Valdivieso ◽  
C Bermudez
Keyword(s):  
Gastrointestinal Tract ◽  
Double Layer ◽  
Single Layer ◽  
Layer Versus
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