scholarly journals Performance of Practical Grounding Systems under High Impulse Conditions

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3187 ◽  
Author(s):  
Muhd Reffin ◽  
Normiza Nor ◽  
Nurul Ahmad ◽  
Syarifah Abdullah
Keyword(s):  
Electrical Properties ◽  
Field Measurements ◽  
Soil Characteristics ◽  
Circular Ring ◽  
Ring Electrode ◽  
Soil Resistivity ◽  
Factors Affecting ◽  
Earthing Systems ◽  
Impulse Characteristics ◽  
Earth Electrode

This paper investigates the factors affecting the impulse characteristics of purposely built grounding systems. We installed 2 m × 2 m grounding systems in four different sites with different soil resistivity values. The effect of impulse polarity on soil characteristics was also investigated for different soil resistivity. A circular ring electrode was used as a return electrode in all four sites. For one of the sites, different configurations of grounding systems were installed to allow the study of the effect of ground electrode configurations on soil characteristics. The aim of this study was to quantify the effects of soil resistivity, impulse polarity, and earth electrode configurations on soil electrical properties under high impulse conditions by field measurements. The new data could be useful in understanding the characteristics of grounding systems in various factors under high impulse conditions. It is hoped that by considering these factors, it can help optimize the design of earthing systems.

scholarly journals Investigations on the Performance of a New Grounding Device with Spike Rods under High Magnitude Current Conditions

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1138 ◽  
Author(s):  
Abdul Abdul Ali ◽  
Nurul Ahmad ◽  
Normiza Mohamad Nor ◽  
Muhd Reffin ◽  
Syarifah Amanina Syed Abdullah
Keyword(s):  
Field Measurements ◽  
Test Results ◽  
High Current ◽  
The Earth ◽  
High Magnitude ◽  
State Test ◽  
Earthing Systems ◽  
Steady State Test ◽  
Impulse Current ◽  
Earth Electrode

In many publications, the characteristics of practical earthing systems were investigated under conditions involving fast-impulse currents of different magnitudes by field measurements. However, as generally known, in practice the transient current can normally reach several tens of kiloamperes. This paper therefore aimed to investigate the characteristics of a new electrode for grounding systems under high current magnitude conditions, and compare it with steady-state test results. The earth electrodes were installed in low resistivity test media, so that high impulse current magnitudes can be achieved. The effects of impulse polarity and earth electrode’s geometry of a new earth electrode were also quantified under high impulse conditions, at high currents (up to 16 kA).

Green roof hydrologic performance and modeling: a review

2013 ◽  
Vol 69 (4) ◽  
pp. 727-738 ◽  
Author(s):  
Yanling Li ◽  
Roger W. Babcock
Keyword(s):  
Peak Flow ◽  
Green Roof ◽  
Field Measurements ◽  
Green Roofs ◽  
Economic Benefits ◽  
Design Parameters ◽  
Technical Literature ◽  
Factors Affecting ◽  
Model Soil ◽  
Runoff Volume

Green roofs reduce runoff from impervious surfaces in urban development. This paper reviews the technical literature on green roof hydrology. Laboratory experiments and field measurements have shown that green roofs can reduce stormwater runoff volume by 30 to 86%, reduce peak flow rate by 22 to 93% and delay the peak flow by 0 to 30 min and thereby decrease pollution, flooding and erosion during precipitation events. However, the effectiveness can vary substantially due to design characteristics making performance predictions difficult. Evaluation of the most recently published study findings indicates that the major factors affecting green roof hydrology are precipitation volume, precipitation dynamics, antecedent conditions, growth medium, plant species, and roof slope. This paper also evaluates the computer models commonly used to simulate hydrologic processes for green roofs, including stormwater management model, soil water atmosphere and plant, SWMS-2D, HYDRUS, and other models that are shown to be effective for predicting precipitation response and economic benefits. The review findings indicate that green roofs are effective for reduction of runoff volume and peak flow, and delay of peak flow, however, no tool or model is available to predict expected performance for any given anticipated system based on design parameters that directly affect green roof hydrology.

scholarly journals Sebaran Limbah Residu CPO (Crude Palm Oil) Bawah Permukaan Tanah Pada PT. SSDP Dengan Aplikasi Geolistrik

2014 ◽  
Vol 1 (2) ◽  
pp. 109
Author(s):  
Dodi Irwan Siregar ◽  
Thamrin Thamrin ◽  
Muhammad Edisar
Keyword(s):  
Palm Oil ◽  
Soil Nutrient ◽  
Field Measurements ◽  
Oil Industry ◽  
Nutrient Content ◽  
Soil Resistivity ◽  
Before And After ◽  
Nutrient Changes ◽  
Bray 1 ◽  
Properties Of Soil

One of the environmental problems caused by the increasing growth of the industry.Industrial waste generated that goes into the soil can alter soil properties. This studyreviewing the nature of the soil as a result of the distribution of residual waste CPO (CrudePalm Oil) industry mills. This study uses the characteristics of resistivity and soil nutrientproperties. Soil resistivity properties were tested by making a model before and after thedistribution of waste residue does CPO. Then validated against field measurements, fieldmeasurements comparing the data with the model. To see the changes in nutrient content ofsoil Laboratory Testing properties of soil nutrient changes. The results showed that theresistivity properties change and nutrient content of the soil before and after the distributionof waste residue subjected CPO. Soil resistivity values that have mixed by CPO residualwaste is higher than the value of soil resistivity is not mixed waste palm oil residues, while thecontent of soil nutrients among other properties, increasing soil pH, Include content C-Organic (%) / Inceneration, P-Available (ppm) / Bray-1, N-Total (%) / Kjedahl decreaseddramatically. 

Soil Resistivity Evaluation and Grounding System Resistance

2018 ◽  
pp. 1-37
Keyword(s):  
Resistivity Measurement ◽  
Potential Method ◽  
Measurement Procedure ◽  
Resistance Testing ◽  
Soil Resistivity ◽  
Factors Affecting ◽  
Grounding Resistance ◽  
Ground Resistance ◽  
Transmission Towers ◽  
Electrode Method

This chapter contains the factors affecting the soil resistivity and grounding resistance such as the soil moisture content, soil mineral content and soil temperature. It discusses the methods of measuring of soil resistivity and grounding resistance using Wenner method. Method to obtain the required samples for obtaining accurate site resistivity is presented. Soil resistivity measurement procedure is given in this chapter. The chapter contains three electrode method or fall-of-Potential method, dead earth method, and ground resistance testing existing systems using ‘Selective' Clamp-on-Measuring of high voltage transmission towers feet resistance. Methods of calculating the apparent soil resistivity of Multi-Layers, apparent soil resistivity of two layers and apparent soil resistivity of three layers are presented in this chapter.

scholarly journals Effect of row width on splash erosion and throughfall in silage maize crops

2017 ◽  
Vol 12 (No. 1) ◽  
pp. 39-50 ◽  
Author(s):  
V. Brant ◽  
P. Zábranský ◽  
M. Škeříková ◽  
J. Pivec ◽  
M. Kroulík ◽  
...  
Keyword(s):  
Stem Elongation ◽  
Field Measurements ◽  
Positive Influence ◽  
Row Spacing ◽  
Growth Stages ◽  
Area Index ◽  
Factors Affecting ◽  
Splash Erosion ◽  
Silage Maize ◽  
Plant Length

Line width is one of the major factors affecting arable soil erosion. The aim of the study was to assess the effects of different row spacing on splash erosion and throughfall in maize crops. Field measurements of the throughfall (P<sub>th</sub>, mm) and splash erosion (MSR, g/m<sup>2</sup>) were carried out in silage maize crops (row spacing 0.45 and 0.75 m) in 2012–2014. The BBCH growth stages for the crops, plant length (L, m), and leaf area index (LAI) were evaluated. Positive correlation was observed between the aerial precipitation (P, mm) and the P<sub>th</sub> values. With increasing P-values, higher levels of P<sub>th</sub> were identified in the 0.75 m compared to the 0.45 m row spacing. The value of this proportion was decreasing from the centre of the inter-row (0.75 m) to the row of the plants direction. Statistically significant lower values of splash erosion were observed in the 0.45 m compared with the 0.75 m wide rows, especially within the years 2012 and 2014. The experiments proved the positive influence of the length of plants and LAI on P/P<sub>th </sub>values. A decrease of P<sub>th </sub> in relation to precipitation values with height of plants and LAI values was observed. This dependency was then confirmed from the beginning of the stem elongation (BBCH 30) to the end of flowering (BBCH 70). Tighter dependency between the plant length (L) and the values of P/P<sub>th</sub> ratio in the 0.75 m wide crop rows was determined. Conversely, a more important influence of LAI on the values of P/P<sub>th</sub> ratio was estimated in the 0.45 m wide crop rows. The experiments proved the positive influence of the 0.45 m wide rows on the decrease of splash erosion as well as throughfall compared with the 0.75 m row spacing.  

Analysis of Earthing System Cabinet of Telekom Malaysia

2015 ◽  
Vol 799-800 ◽  
pp. 1249-1256
Author(s):  
David Caulker ◽  
Mohd Annuar Ramli
Keyword(s):  
Computer Simulation ◽  
Simulation Software ◽  
Current Injection ◽  
Soil Conditions ◽  
Soil Resistivity ◽  
Specific Location ◽  
Local Soil ◽  
Local Soil Conditions ◽  
Earthing Systems ◽  
The Impact

This paper investigated the impact on the earthing systems of cabinets of Telekom Malaysia (TM) when subjected to dangerous voltages due to current injection from remote sources. TM have received numerous cases regarding the failures of their cabinets due to power related issues (PRI) as well as lightning. These failures may have occurred partly due to the existing earthing systems installations. This research aims to determine earthing impedance of 5 ohms or less of TM cabinets with respect to local soil conditions. Low impedance earthing is not easy to realize mainly due to the local soil resistivity, layering and structures. To achieve a low impedance of below 5 ohms as per Telekom Malaysia's requirement, three types of earthing electrodes were modelled and simulated using CDEGS computer simulation software. Results have demonstrated that the existing earthing system of 3 rods practice by TM is sufficient for areas of resistivity less than 500ٹ-m. Combination of rectangular and vertical rods for resistivity of 500ٹ-m above is the preferred choice of earthing. Analysis and discussions presented in this study can be used as a guide for TM for their cabinet installations. Results also highlighted that achieving less than 5ٹ does not constitute a safe earthing system. Other parameters have to be taken into account before ascertain which type of earthing to be used in a specific location of a TM installation.

Mechanism and affecting factors of Translohr tramway guide rail side wear

2016 ◽  
Vol 231 (21) ◽  
pp. 3898-3912 ◽  
Author(s):  
Yuanjin Ji ◽  
Lihui Ren ◽  
Jian Wang ◽  
Dao Gong
Keyword(s):  
Mechanical Model ◽  
Field Measurements ◽  
Affecting Factors ◽  
Critical Factors ◽  
Guide Rail ◽  
Factors Affecting ◽  
Rail Track ◽  
Equivalent Mechanical Model ◽  
Two Factors ◽  
Curve Radius

The wheel–rail contact can be found in two patterns. In the first pattern, the treads of both wheels are in contact with the two top surfaces of the ^-shaped guide rail; in the second pattern, the treads of both wheels are in contact with the two top surfaces of the ^-shaped guide rail, and the wheel edge is in contact with the guide rail web on one side. Based on these findings, an equivalent mechanical model with four unilateral springs is proposed to describe the wheel–rail contact. Additionally, a dynamic model of the Translohr tramway is established using Matlab/Simulink. The wheel–rail contact in a tramway moving along curves with different radii is calculated using simulation, and the results obtained are consistent with the observations and results of field measurements. The effects of various factors, including curve radius, tram speed, guide rail pre-pressure, and guide rod length, on the side wear of the guide rail were investigated. The results revealed that curve radius and tram speed are the critical factors affecting rail track side wear. These two factors can qualitatively determine rail track side wear, while other factors can only quantitatively affect the degree of rail track side wear.

Effect of Growth Conditions on Structural and Electrical Properties of Pb(ZrxTi1−x)O3 layers grown by peroxide MBE

2007 ◽  
Vol 1034 ◽  
Author(s):  
Natalia Izyumskaya ◽  
V. Avrutin ◽  
X. Gu ◽  
B. Xiao ◽  
S. Chevtchenko ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Phase Composition ◽  
Electrical Properties ◽  
Ferroelectric Properties ◽  
Field Measurements ◽  
Growth Conditions ◽  
Second Phase ◽  
Conductive Atomic Force Microscopy ◽  
Structural And Electrical Properties ◽  
Pzt Films

AbstractPb(ZrxTi1−x)O3 (PZT) films were grown by molecular beam epitaxy using hydrogen peroxide as a source of reactive oxygen. Phase composition as well as structural and electrical properties of the films were studied by x-ray diffractometry, scanning and transmission electron microscopy, conductive atomic force microscopy, and electrical (I-V and polarization-field) measurements. The hydrogen peroxide pressure was found to control the phase composition of the films. Excess peroxide leads to PbO inclusions in PZT layers, whereas deficiency results in the TiO2 or the ZrO2 phase. The second-phase inclusions can be responsible for high leakage current in the films. Precise control over the peroxide pressure is imperative for single-phase PZT films with good ferroelectric properties.

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