Parameters of the normal gravity field deduced from satellite observations

1971 ◽  
Vol 15 (2) ◽  
pp. 124-131 ◽  
Author(s):  
Milan Burša ◽  
J. Picha
Keyword(s):  
Gravity Field ◽  
Normal Gravity ◽  
Satellite Observations

scholarly journals GRACETOOLS—GRACE Gravity Field Recovery Tools

Geosciences ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 350 ◽  
Author(s):  
Neda Darbeheshti ◽  
Florian Wöske ◽  
Matthias Weigelt ◽  
Christopher Mccullough ◽  
Hu Wu
Keyword(s):  
Open Source ◽  
Gravity Field ◽  
Transition Matrix ◽  
State Transition ◽  
Satellite Observations ◽  
Gravity Field Recovery ◽  
Grace Data ◽  
Range Rate ◽  
Analysis Platform ◽  
Recovery Tools

This paper introduces GRACETOOLS, the first open source gravity field recovery tool using GRACE type satellite observations. Our aim is to initiate an open source GRACE data analysis platform, where the existing algorithms and codes for working with GRACE data are shared and improved. We describe the first release of GRACETOOLS that includes solving variational equations for gravity field recovery using GRACE range rate observations. All mathematical models are presented in a matrix format, with emphasis on state transition matrix, followed by details of the batch least squares algorithm. At the end, we demonstrate how GRACETOOLS works with simulated GRACE type observations. The first release of GRACETOOLS consist of all MATLAB M-files and is publicly available at Supplementary Materials.

scholarly journals A novel electro-catalytic degradation method of phenol wastewater with Ti/IrO2-Ta2O5 anodes in high-gravity fields

2017 ◽  
Vol 76 (3) ◽  
pp. 662-670 ◽  
Author(s):  
Jing Gao ◽  
Junjuan Yan ◽  
Youzhi Liu ◽  
Jiacheng Zhang ◽  
Zhiyuan Guo
Keyword(s):  
Energy Consumption ◽  
Gravity Field ◽  
Normal Gravity ◽  
Catalytic Degradation ◽  
Degradation Efficiency ◽  
High Gravity ◽  
Electrolysis Time ◽  
Removal Efficiencies ◽  
High Gravity Field ◽  
Phenol Wastewater

In the electro-catalytic degradation process of phenol wastewater, bubbles and mass transfer limitation will result in the decrease in wastewater degradation efficiency, a long electrolysis time and a high energy consumption. Self-made Ti/IrO2-Ta2O5 anodes and a high-gravity electro-catalytic reactor were used to improve them. The Ti/IrO2-Ta2O5 anode was prepared with a thermal decomposition method and characterized by scanning electron microscopy (SEM). Under optimum conditions, the removal efficiencies of phenol, total organic carbon (TOC) and chemical oxygen demand (COD) respectively reached 94.77%, 50.96% and 41.2% after 2 h electrolysis in the high-gravity field, which were respectively 10.93%, 16.72% and 24.84% higher than those in the normal gravity field. For about the same removal efficiencies, the electrolysis time and energy consumed in the high-gravity field were 33.3% and 15.4% lower than those consumed in the normal gravity field, respectively. The degradation pathway of phenol detected by high performance liquid chromatography (HPLC) was unchanged in the high-gravity field, but the degradation rate of phenol increased. The Ti/IrO2-Ta2O5 anode provided good stability because the removal efficiencies of phenol and TOC decreased slightly and the surface morphology of the coating was almost unchanged when it had been used in electrolysis for 11 months, about 1,200 h, in the high-gravity field. Results indicated that the phenol wastewater degradation efficiency was improved, the time was shortened, and the energy consumption was reduced in the high-gravity field.

The normal vertical gradient of gravity

Geophysics ◽  
1983 ◽  
Vol 48 (7) ◽  
pp. 1011-1013 ◽  
Author(s):  
John H. Karl
Keyword(s):  
Gravity Field ◽  
Potential Field ◽  
Large Scale ◽  
Normal Gravity ◽  
Vertical Gradient ◽  
Original Model ◽  
Field Methods ◽  
The Earth ◽  
Vertical Gradient Of Gravity

Most gravity surveys are conducted to estimate subsurface density contrasts for one application or another. From large‐scale crustal studies to relatively small exploration surveys, it is necessary to determine in some way what the normal gravity field should be in order to identify anomalous features. The anomalies then represent deviations to be interpreted in light of the original model. It is a central limitation of potential field methods that this model, sometimes representing a so‐called “regional” field, is not unique. In the case of gravity, this model has traditionally involved geometrical approximations. It is generally assumed that variations in station elevations are small compared with the radius of the earth—an obviously excellent approximation, but one needs to be mathematically consistent.

Studies with Centrifuge Vane and Penetrometer Apparatus in a Normal Gravity Field

1989 ◽  
Vol 12 (3) ◽  
pp. 195 ◽  
Author(s):  
VP Drnevich ◽  
MCR Davies ◽  
MSS Almeida ◽  
RHG Parry
Keyword(s):  
Gravity Field ◽  
Normal Gravity
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