Auxiliary Axis for Rensselaer’s Geotechnical Centrifuge Center In-Flight Robot: Design Considerations

2007 ◽  
Author(s):  
Glenn Saunders ◽  
Stephen J. Derby ◽  
Tarek H. Abdoun
Keyword(s):  
Soil Samples ◽  
Soil Conditions ◽  
Robot Design ◽  
Deep Soil ◽  
Geotechnical Centrifuge ◽  
Design Considerations ◽  
Earthen Structures ◽  
Laminar Box ◽  
Conducting Research ◽  
Earthquake Simulations

Rensselaer’s Geotechnical Centrifuge Center is a resource for conducting research into the behavior of soils, earthen structures and other materials under high g-force conditions. The 3m radius centrifuge can accelerate a roughly 1m × 1m × 1m payload up to as much as 200 g’s. Under such loading, properly prepared soil samples accurately simulate deep soil conditions at 1 g. The system also includes an In-flight Robot that provides the capability to perform experiments while the centrifuge is in operations, as well as a 2–D shaker and associated 2–D Laminar Box that permit earthquake simulations while in flight. However prior to the implementation of the Auxiliary Axis, pilings were limited to a maximum usable length of approximately 15cm. The objective of Auxiliary Axis is to provide the capability to handle long pilings (up to 35cm) in situations where both the 2–D Shaker and 2–D Laminar Box are used. The Aux Axis is attached to the exterior of the in-flight robot when needed, and removed when not. The Aux Axis is designed to perform in a 50 g’s environment which holds some unique engineering concerns. It is designed so that installation and removal is as simple as possible, and can typically be completed in about 30 minutes. The Aux Axis is powered by the existing robot Z axis motor and belt drive system. Consequently, both the Z axis and the Aux Axis move simultaneously when the Aux Axis is installed. The Aux Axis is geared approximately 8.42 times higher than the Z axis so that it moves much further than the Z axis during operation. This permits the pilings; which are attached to the Aux Axis, to be fully inserted into the soil sample before the Z axis has moved far enough to interfere with the top of the 2–D Laminar Box.

scholarly journals Complementary Use of Magnetometric Measurements for Geochemical Investigation of Light REE Concentration in Anthropogenically Polluted Soils

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 457
Author(s):  
Piotr Fabijańczyk ◽  
Jarosław Zawadzki
Keyword(s):  
Soil Samples ◽  
Soil Conditions ◽  
Soil Cores ◽  
Light Rare Earth ◽  
Polluted Soils ◽  
Chemical Measurements ◽  
Geochemical Investigation ◽  
Light Rare Earth Elements ◽  
Soil Magnetic Susceptibility ◽  
Geophysical Measurements

The purpose of this study was to use fast geophysical measurements of soil magnetic susceptibility (κ) as supplementary data for chemical measurements of selected light rare earth elements (REEs) in soil. In order to ensure diversity in soil conditions, anthropogenic conditions and types of land use, seven areas were selected, all located in regions subjected to past or present industrial pollution. Magnetometric parameters were measured using a selected magnetic sensor that was specially designed for measurements of soil cores and were used to classify collected soil cores into six distinctive types. The analysis of REEs concentrations in soil was carried out taking into account the grouping of collected soil samples based on the type of study area (open, forested and mountain), and additionally on the measured magnetometric parameters of collected soil cores. A use of magnetometric measurements provided different, but complementary to chemical measurements information, which allowed to obtain deeper insight on REEs concentrations in soils in studied areas.

scholarly journals Improved representations of coupled soil-canopy processes in the CABLE land surface model

2016 ◽  
Author(s):  
Vanessa Haverd ◽  
Matthias Cuntz ◽  
Lars P. Nieradzik ◽  
Ian N. Harman
Keyword(s):  
Water Use ◽  
Land Surface ◽  
Land Surface Model ◽  
Heat Fluxes ◽  
Soil Conditions ◽  
Surface Model ◽  
Drought Response ◽  
Deep Soil ◽  
Stable Conditions ◽  
Water Use Efficiencies

Abstract. CABLE is a global land surface model, which has been used extensively in offline and coupled simulations. While CABLE performs well in comparison with other land surface models, results are impacted by decoupling of transpiration and photosynthesis fluxes under drying soil conditions, often leading to implausibly high water use efficiencies. Here we present a solution to this problem, ensuring that modeled transpiration is always consistent with modeled photosynthesis, while introducing a parsimonious single-parameter drought response function which is coupled to root water uptake. We further improve CABLE’s simulation of coupled soil-canopy processes by introducing an alternative hydrology model with a physically accurate representation of coupled energy and water fluxes at the soil/air interface, including a more realistic formulation of transfer under atmospherically stable conditions within the canopy and in the presence of leaf litter. The effects of these model developments are assessed using data from 18 stations from the global Eddy covariance flux network FLUXNET, selected to span a large climatic range. Marked improvements are demonstrated, with root-mean-squared errors for monthly latent heat fluxes and water use efficiencies being reduced by 40 %. Results highlight the important roles of deep soil moisture in mediating drought response and litter in dampening soil evaporation.

scholarly journals Draft Requirement of Two Animal - Drawn Institute for Agricultural Research (IAR) Weeders

2020 ◽  
pp. 14-20
Author(s):  
Y. A. Unguwanrimi ◽  
A. M. Sada ◽  
G. N. Ugama ◽  
H. S. Garuba ◽  
A. Ugoani
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Bulk Density ◽  
Soil Moisture Content ◽  
Agricultural Research ◽  
Soil Samples ◽  
Soil Conditions ◽  
Experimental Plot ◽  
Moisture Contents ◽  
Loam Soil

Draft requirements of two animal – drawn (IAR) weeders operating on loam soil were determined in the study. The implements include a straddle row weeder and an emcot attached rotary weeder evaluated under the same soil conditions, using a pair of white Fulani breed of oxen. The animal draft requirement was first estimated from the animal ergonomics measurements. Using area of 0.054 hectare as experimental plot for each implement the draft requirement of each implement was investigated after taking soil samples for soil moisture content and bulk density determinations. The implements tested showed variation in their average draft requirement. The straddle row weeder had the highest value of 338.15 N respectively while the emcot attached rotary weeder had the lowest value of 188.12 N with 47.03%, respectively. The average soil moisture contents and bulk density were 13.0% and 1.46%/cm3, respectively.

Spatial Distribution and Reserves Estimation of Soil Organic Carbon Based on GIS in Maiji Area of Tianshui

2013 ◽  
Vol 316-317 ◽  
pp. 299-306
Author(s):  
Ai Hong Gai ◽  
Ren Zhi Zhang ◽  
Fang Chen ◽  
Xiao Long Wang
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Average Density ◽  
Soil Survey ◽  
Soil Conditions ◽  
Carbon Density ◽  
Deep Soil ◽  
Soil Organic Carbon Density ◽  
Secondary Survey ◽  
Organic Carbon Storage

The soil organic carbon density and storage of Maiji Area of Tianshui was estmiated, using the data of 6060 soil profile from the second soil survey of China and formulating fertilization for soil conditions in 2008. Integrating the soil map, land use status map and district map of Maiji Area of Tianshui, the index of the characteristic of soil organic distribution in different soil and soil layers were analyzed. Results showed: the soil of Maiji area have low average density, when soil secondary census, depths of 5cm,20cm,1m average density of organic carbon are 0.92kg•m-2,3.31kg•m-2,7.79kg•m-2 respectively, average density of organic carbon at depth of 20cm is 2.43 kg•m-2 in 2008 years, As a standard of Yu Dongsheng’s (2005) estimation of average density of 9.60 kg•m-2 in the depth of 1m all over the China, Maiji area 1m deep soil organic carbon density is lower 1.91kg•m-2 than the average density of whole country; The calculation of the secondary survey, reserves of organic carbon in surface soil (0-5cm) is about 4.83×106t, reserves of organic carbon in fall (0-20cm) is about 12.46×106t, reserves of soil organic carbon in 1m depth is about 45.17×106t, reserves of soil organic carbon in fall (0-20cm) is about 18.55×106t in 2008 years. In a word, the soil organic carbon storage was relatively indigent in Maiji Area of Tianshui.

Evaluation of Dynamic Behavior of Pile Foundations for Interim Storage Facilities Through Geotechnical Centrifuge Tests

2002 ◽  
Author(s):  
Shizuo Tsurumaki ◽  
Hiroyuki Watanabe ◽  
Akira Tateishi ◽  
Kenichi Horikoshi ◽  
Shunichi Suzuki
Keyword(s):  
Dynamic Behavior ◽  
Experimental Studies ◽  
Centrifuge Modeling ◽  
Pile Foundations ◽  
Soil Conditions ◽  
Confining Stress ◽  
Geotechnical Centrifuge ◽  
Centrifuge Tests ◽  
Interim Storage ◽  
Storage Facilities

In Japan, there is a possibility that interim storage facilities for recycled nuclear fuel resources may be constructed on quaternary layers, rather than on hard rock. In such a case, the storage facilities need to be supported by pile foundations or spread foundations to meet the required safety level. The authors have conducted a series of experimental studies on the dynamic behavior of storage facilities supported by pile foundations. A centrifuge modeling technique was used to satisfy the required similitude between the reduced size model and the prototype. The centrifuge allows a high confining stress level equivalent to prototype deep soils to be generated (which is considered necessary for examining complex pile-soil interactions) as the soil strength and the deformation are highly dependent on the confining stress. The soil conditions were set at as experimental variables, and the results are compared. Since 2000, the Nuclear Power Engineering Corporation (NUPEC) has been conducting these research tests under the auspices on the Ministry of Economy, Trade and Industry of Japan.

scholarly journals Soil acidity and mobile aluminum status in pseudogley soils in Cacak-Kraljevo basin

2012 ◽  
Vol 77 (6) ◽  
pp. 833-843 ◽  
Author(s):  
Ivica Djalovic ◽  
Djordje Jockovic ◽  
Goran Dugalic ◽  
Goran Bekavac ◽  
Bozana Purar ◽  
...  
Keyword(s):  
Forest Soil ◽  
Forest Soils ◽  
Soil Acidity ◽  
Arable Land ◽  
Soil Samples ◽  
Soil Conditions ◽  
Arable Soils ◽  
Mean Values ◽  
Exchangeable Acidity ◽  
The Mean

Soil acidity and aluminum toxicity are considered most damaging soil conditions affecting the growth of most crops. This paper reviews the results of tests of pH, exchangeable acidity and mobile aluminum (Al) concentration in profiles of pseudogley soils from Cacak-Kraljevo basin. For that purpose, 102 soil pits were dug in 2009 in several sites around Cacak- Kraljevo basin. The tests encompassed 54 field, 28 meadow, and 20 forest soil samples. Samples of soil in the disturbed state were taken from the Ah and Eg horizons (102 samples), from the B1tg horizon in 39 field, 24 meadow and 15 forest pits (a total of 78 samples) and from the B2tg horizon in 14 field, 11 meadow, and 4 forest pits (a total of 29 samples). Mean pH values (1M KCl) of the tested soil profiles were 4.28, 3.90 and 3.80 for the Ah, Eg and B1tg horizons, respectively. Soil pH of forest samples was lower than those in meadow and arable land samples (mean values of 4.06, 3.97 and 3.85 for arable land, meadow and forest samples, respectively). Soil acidification was especially intensive in deep horizons, as 27% (Ah), 77% (Eg) and 87% (B1tg) soil samples had the pH value below 4.0. Mean values of total exchangeable acidity (TEA) were 1.55, 2.33 and 3.40 meq 100 g-1 for the Ah, Eg and B1tg horizons, respectively. The TEA values in forest soils were considerably higher (3.39 meq 100 g-1) than those in arable soils and meadow soils (1.96 and 1.93, respectively). Mean mobile Al contents of tested soil samples were 11.02, 19.58 and 28.33 mg Al 100 g-1 for the Ah, Eg and B1tg horizons, respectively. According to the pH and TEA values, mobile Al was considerably higher in the forest soils (the mean value of 26.08 mg Al 100 g-1) than in the arable soils and meadow soils (the mean values of 16.85 and 16.00 mg Al 100 g-1, respectively). The Eg and B1tg horizons of the forest soil had especially high mobile Al contents (the mean values of 28.50 and 32.95 mg Al 100 g-1, respectively). High levels of mobile Al were especially frequent in the forest soils, with 35% (Ah), 85.0% (Eg) and 93.3% (B1tg) of the tested samples ranging above 10 mg Al 100 g-1.

Field calibration of a capacitance soil water probe in heterogeneous fields

Soil Research ◽  
2004 ◽  
Vol 42 (3) ◽  
pp. 289 ◽  
Author(s):  
Dieter Geesing ◽  
Martin Bachmaier ◽  
Urs Schmidhalter
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Samples ◽  
Soil Conditions ◽  
Site Specific ◽  
Field Calibration ◽  
Calibration Methods ◽  
Significant Difference ◽  
Capacitance Probe

Soil water research requires methods to perform accurate measurements. A capacitance probe gauge has characteristics that seem to make it an attractive replacement for neutron scatter gauges to measure soil water content, but there is evidence that capacitance systems should be calibrated for individual soils. Laboratory calibrations and many field calibration methods are costly and time-consuming, and controlled conditions and disturbed soil samples do not always reflect field conditions, and thus, they are inadequate for practical use. The objectives of the present study were (i) to test a simple field calibration method for a recently developed capacitive sensor even under highly variable soil texture conditions, and (ii) to validate this approach under various soil moisture conditions. Soil samples were taken 0.5 m from the access tube of the sensor and a whole field calibration and several site-specific calibrations were developed using 10–142 observations per site under different soil water regimes. A regression of soil water content estimated by sensor reading on water content obtained by core sampling showed no significant difference in the slope and intercept of the 1:1 line when the field calibration was applied. However, the precision of the calibration was only considerably increased if the estimations were based on site-specific calibrations developed on at least 35 observations per site. The precision and accuracy of the calibration equations were not affected when data were obtained only under wet or dry soil conditions. The method presented in this paper is a speedy and cheap way to calibrate capacitance probe sensors.

scholarly journals Ecology of Bacterial Pathogens Associated With Public Waste Dumpsites and their Public Health Consequences

2018 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Public Health ◽  
Prevalence Rate ◽  
Ph Value ◽  
Close Contact ◽  
Soil Samples ◽  
Public Health Issue ◽  
Health Consequences ◽  
Deep Soil ◽  
Dump Site ◽  
Significant Difference

Human societies generates large amount of waste routinely thus, waste has increasingly becomes a huge public health issue, if we must check the sporadic upsurge of epidemic outbreaks in our communities. Nonetheless, indiscriminate dumping of waste breeds different arrays of microorganisms that have been implicated with myriads of health hazards with massive public health consequences. Therefore; there is urgent need to understand the pathogens that are associated with a public waste dump site and its Public Health implications. This observational study explored the collection of two soil samples (surface and deep), from three different sampling stations. The samples were analysed for pH and aerobic heterotrophic bacterial counts using the standard analytic procedures. Both parametric (unpaired two sample t-test) and non-parametric (Mann Whitney U, Wilcoxon and Kruskalwallis) test statistics were performed at 5% significance level. Also descriptive statistics of frequency, percentage, mean and standard deviation and prevalence rate were also explored. The statistical analysis was done using Graphpad calculator and SPSS version 21. The mean pH value of the soils ranged from pH 6.78±0.01to 7.30±0.01with no significant difference (P > 0.05) between soil levels. Heterotrophic bacterial count ranged from 1.6x108 ±1.0x106 cfu/g soil to 4.4x108 ±5.8x106 cfu/g soil. However, there was a significant difference (P < 0.05) between surface and deep soil samples. However, frequency distribution and prevalence rate revealed the probable isolates in a decreasing prevalence order Nonetheless, of Bacillus spp52 (29.4%)> Proteus spp50 (28.3%)>Klebsiellaspp37 (20.9%)>Staph auerus27 (15.3%)>Pseudomasspp6 (3.4%)> Staph. Spp5 (2.8%). The common diseases caused by these microbes range from zoonotic diseases such as Anthrax to urinary trait infections, food borne infection, wound infection and septicaemia respectively. It is therefore very critical that students and University staff in close contact with any of these dumpsites with these associated public health pathogens are at risk of acquiring the above illness thus, there is urgent need for proper waste management and smart sanitation strategy intervention in the region.

scholarly journals Peningkatan Stabilitas Lereng pada Ruas Jalan Tawaeli – Toboli dengan Vegetasi/Bioengineering

2021 ◽  
pp. 23-32
Author(s):  
S.A. Wandira ◽  
A. Rahayu
Keyword(s):  
Shear Strength ◽  
Slope Stability ◽  
Safety Factor ◽  
Friction Angle ◽  
Soil Samples ◽  
Plant Roots ◽  
Soil Conditions ◽  
Mountainous Area ◽  
Stability Calculation ◽  
The Road

Tawaeli - Toboli is one of the road that often undergo landslide. Most of these roads are in a mountainous area with high steep slopes and poor soil conditions. The road conditions worsened, especially in rainy season resulting the citizen do not know anywhere that is prone to landslides such as in Km 16 to 17. The purpose of this study was to analyze slope stability using bioengineering methods, determine the shear strength of soil without plant roots and soil with plant roots and to determine the potential for landslides that will occur. Bioengineering is used to increase the strength of the soil, and stabilize slopes and reduce erosion on slopes. The slope stability calculation using the Bishop slice method. The calculating of safety factor analyzed using the Slope / W application and manually. Soil samples were taken from 3 (three) points and the soil strength parameters,  soil cohesion and friction angle, were obtained through laboratory testing. Tests were carried out using rootless and rooted soil samples. In addition, direct field observations were made to obtain slope angles and slope heights. The results showed that the parameters of soil shear strength, cohesion and friction angle increased with the presence of plant roots. The results of the slope stability analysis show that the conditions of the slope are stable at slope 1 (Km 16) and slope 3 (Km 17) with a safety factor greater than 1.5. While slope 2 (Km 16 +300) has the potential for landslides as a safety factor of less than 1.5. The use of bioengineering increases the safety factor to be greater than 1.5. The calculation of the value of the safety factor using the Slope / W program and the Bishop manual is not much different, but the calculation time with the Slope / W program is faster

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