In situ bulk density estimates from borehole gravity data in limestones of the Madison Group, test well No. 2, Custer County, Montana

1980 ◽  
Author(s):  
Bruce A. Kososki ◽  
Stephen L. Robbins
Keyword(s):  
Bulk Density ◽  
Gravity Data ◽  
Density Estimates ◽  
Group Test ◽  
Custer County

Reexamination of the values used as constants in calculating rock density from borehole gravity data

Geophysics ◽  
1981 ◽  
Vol 46 (2) ◽  
pp. 208-210 ◽  
Author(s):  
Stephen L. Robbins
Keyword(s):  
Bulk Density ◽  
Research Program ◽  
Gravity Data ◽  
Geological Survey ◽  
Rock Density ◽  
The U.S

The U.S. Geological Survey has a research program in bore‐hole gravimetry (Mast, 1978, p. 17). As part of this program, I have been examining the accuracy of constants F and k used in the formula for determining in‐situ bulk density from borehole gravity data.

scholarly journals A time series assessment of terrestrial water storage and its relationship with hydro-meteorological factors in Gilgit-Baltistan region using GRACE observation and GLDAS-Noah model

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Dostdar Hussain ◽  
Aftab Ahmed Khan ◽  
Syed Najam Ul Hassan ◽  
Syed Ali Asad Naqvi ◽  
Akhtar Jamil
Keyword(s):  
Snow Water Equivalent ◽  
Gravity Data ◽  
Water Storage ◽  
Indus Basin ◽  
Flood Hazards ◽  
Terrestrial Water Storage ◽  
Satellite Gravity ◽  
Terrestrial Water ◽  
Gilgit Baltistan

AbstractMountains regions like Gilgit-Baltistan (GB) province of Pakistan are solely dependent on seasonal snow and glacier melt. In Indus basin which forms in GB, there is a need to manage water in a sustainable way for the livelihood and economic activities of the downstream population. It is important to monitor water resources that include glaciers, snow-covered area, lakes, etc., besides traditional hydrological (point-based measurements by using the gauging station) and remote sensing-based studies (traditional satellite-based observations provide terrestrial water storage (TWS) change within few centimeters from the earth’s surface); the TWS anomalies (TWSA) for the GB region are not investigated. In this study, the TWSA in GB region is considered for the period of 13 years (from January 2003 to December 2016). Gravity Recovery and Climate Experiment (GRACE) level 2 monthly data from three processing centers, namely Centre for Space Research (CSR), German Research Center for Geosciences (GFZ), and Jet Propulsion Laboratory (JPL), System Global Land Data Assimilation System (GLDAS)-driven Noah model, and in situ precipitation data from weather stations, were used for the study investigation. GRACE can help to forecast the possible trends of increasing or decreasing TWS with high accuracy as compared to the past studies, which do not use satellite gravity data. Our results indicate that TWS shows a decreasing trend estimated by GRACE (CSR, GFZ, and JPL) and GLDAS-Noah model, but the trend is not significant statistically. The annual amplitude of GLDAS-Noah is greater than GRACE signal. Mean monthly analysis of TWSA indicates that TWS reaches its maximum in April, while it reaches its minimum in October. Furthermore, Spearman’s rank correlation is determined between GRACE estimated TWS with precipitation, soil moisture (SM) and snow water equivalent (SWE). We also assess the factors, SM and SWE which are the most efficient parameters producing GRACE TWS signal in the study area. In future, our results with the support of more in situ data can be helpful for conservation of natural resources and to manage flood hazards, droughts, and water distribution for the mountain regions.

scholarly journals Techno-Economic Feasibility of In Situ Vegetable Residue Return in the Chinese Solar Greenhouse

Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1828
Author(s):  
Xiaoxuan Wei ◽  
Yansu Li ◽  
Xiaoguang Fan ◽  
Chaoxing He ◽  
Yan Yan ◽  
...  
Keyword(s):  
Bulk Density ◽  
Soil Ph ◽  
Sustainable Use ◽  
Economic Feasibility ◽  
Remarkable Increase ◽  
Rotation Pattern ◽  
Solar Greenhouse ◽  
Final Harvest ◽  
Vegetable Cultivation

The tremendous scale of protected vegetable cultivation incidentally produces considerable vegetable residue, which refers to the remaining parts of plants after the final harvest. The low use rate of vegetable residue results in nutrient waste and environmental pressure in China. In this study, we put forward vegetable residue directly returned to the soil and investigated its feasibility. Residue return was steadily conducted 5 times in a Chinese solar greenhouse with the cucumber–tomato rotation pattern. Results showed that residue return increased the soil alkali-hydrolysed nitrogen and available potassium contents by 4.97–26.22% and 9.31–21.92%, respectively, along with slightly reduced soil pH and bulk density by 1.00–5.39% and 6.72–11.81%, respectively. Gemmatimonadetes, Firmicutes, Acidobacteria, Basidiomycota, and Mortierellomycota were the major phyla with noticeable changes when residue return was conducted 5 times. Fruit yield began to obtain remarkable increase by 5.81–9.26 t·ha−1 after residue return was conducted 3 times, bringing about additional profits of 5382.0–8519.2 USD·ha−1. Residue return could cut down the disposal expense of vegetable residues by 480.89 USD·ha−1. Moreover, residue return could supplement nutrients to soil, potentially contributing to reducing chemical fertilizer inputs. In conclusion, in situ vegetable residue return could be considered to be a feasible and sustainable use technique for vegetable residues in the Chinese solar greenhouse.

In Situ Monitoring of Soil Bulk Density with a Thermo-TDR Sensor

2014 ◽  
Vol 78 (2) ◽  
pp. 400-407 ◽  
Author(s):  
Xiaona Liu ◽  
Sen Lu ◽  
Robert Horton ◽  
Tusheng Ren
Keyword(s):  
Bulk Density ◽  
Soil Bulk Density ◽  
In Situ Monitoring

scholarly journals Nonintrusive Depth Estimation of Buried Radioactive Wastes Using Ground Penetrating Radar and a Gamma Ray Detector

2019 ◽  
Vol 11 (2) ◽  
pp. 141 ◽  
Author(s):  
Ikechukwu Ukaegbu ◽  
Kelum Gamage ◽  
Michael Aspinall
Keyword(s):  
Bulk Density ◽  
Ground Penetrating Radar ◽  
Gamma Ray ◽  
Depth Estimation ◽  
Average Error ◽  
Density Estimates ◽  
Material Density ◽  
Linear Correction ◽  
Ground Penetrating ◽  
Gamma Ray Detector

This study reports on the combination of data from a ground penetrating radar (GPR) and a gamma ray detector for nonintrusive depth estimation of buried radioactive sources. The use of the GPR was to enable the estimation of the material density required for the calculation of the depth of the source from the radiation data. Four different models for bulk density estimation were analysed using three materials, namely: sand, gravel and soil. The results showed that the GPR was able to estimate the bulk density of the three materials with an average error of 4.5%. The density estimates were then used together with gamma ray measurements to successfully estimate the depth of a 658 kBq ceasium-137 radioactive source buried in each of the three materials investigated. However, a linear correction factor needs to be applied to the depth estimates due to the deviation of the estimated depth from the measured depth as the depth increases. This new application of GPR will further extend the possible fields of application of this ubiquitous geophysical tool.

Thermo–time domain reflectometry method: Advances in monitoring in situ soil bulk density

2020 ◽  
Vol 84 (5) ◽  
pp. 1354-1360
Author(s):  
Yili Lu ◽  
Xiaona Liu ◽  
Meng Zhang ◽  
Joshua Heitman ◽  
Robert Horton ◽  
...  
Keyword(s):  
Bulk Density ◽  
Time Domain ◽  
Soil Bulk Density ◽  
Time Domain Reflectometry

In Situ Formation of Mullite-Al2O3 Refractory Ceramic from Al-Matrix Mixtures

2014 ◽  
Vol 602-603 ◽  
pp. 628-631
Author(s):  
Xing Yong Gu ◽  
Ping Li ◽  
Wei Xia Dong ◽  
Ting Luo
Keyword(s):  
Thermal Expansion ◽  
Bulk Density ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Bending Strength ◽  
Potential Effect ◽  
Apparent Porosity ◽  
Mullite Phase ◽  
Two Samples

Two types of mullite-Al2O3 composites were designed and sintered in situ from different composition containing Al composites e.g. kaolin, alumina hydroxide and calcined bauxite etc, and auxiliary additives. The phase composition and microstructure were studied using X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. Bulk density, apparent porosity, thermal expansion coefficient and bending strength were also measured. The two samples exhibited XRD reflections characteristic of alumina and mullite phases. The amount of these phases depended on starting batch compositions, and reaction of starting and auxiliary materials together to form mullite. Because of in-situ formation of mullite fiber, the bulk density and bending strength were improved and apparent porosity was decreased for the composites with uniform microstructure. The presence of high mullite phase was found to decrease the thermal expansion coefficient. The potential effect of these morphologies and phase on properties was discussed. These mullite-Al2O3 composite was expected to have major applications in the areas of refractory material.

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