scholarly journals A new form of Saturn's magnetopause using a dynamic pressure balance model, based on in situ, multi-instrument Cassini measurements

2010 ◽  
Vol 115 (A6) ◽  
pp. n/a-n/a ◽  
Author(s):  
S. J. Kanani ◽  
C. S. Arridge ◽  
G. H. Jones ◽  
A. N. Fazakerley ◽  
H. J. McAndrews ◽  
...  
Keyword(s):  
Dynamic Pressure ◽  
Balance Model ◽  
Pressure Balance ◽  
Model Based ◽  
New Form

Research on Underground Dynamic Fluid Pressure Balance in the Process of Oil Shale In-Situ Fracturing-Nitrogen Injection Exploitation

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Chen Chen ◽  
Shuai Gao ◽  
Youhong Sun ◽  
Wei Guo ◽  
Qiang Li
Keyword(s):  
High Pressure ◽  
Field Experiment ◽  
Ground Water ◽  
Oil Shale ◽  
Dynamic Pressure ◽  
Nitrogen Pressure ◽  
Production Well ◽  
Pressure Balance ◽  
Nitrogen Injection

Oil shale in-situ retorting is a reasonable development technology. However, the ground water may flow into fractures in oil shale layer that impact the process of oil shale in-situ retorting. This paper introduced oil shale in-situ fracturing-nitrogen injection exploitation and a method of dynamic pressure balance between the ground water and high pressure nitrogen to keep the oil shale layer without ground water in the process of oil shale in-situ fracturing-nitrogen injection exploitation. Theoretical basis of dynamic pressure balance between ground water and nitrogen was established through analyzing pressure relationship between ground water and nitrogen in the fractures and field experiment was conducted according to the method. The field experiment results showed that nitrogen pressure maintained high level in the fractures during the stage of building pressure balance of nitrogen and ground water and pushed ground water out of the oil shale layer. Then, nitrogen pressure in the fractures reduced and maintained stable because part of nitrogen in the fractures flowed out from the production well and flow conductivity of fractures enhanced. After the balance between the ground water and high pressure nitrogen was established, water yield of production well reduced more than 85%. It explained that the balance has function of sealing up.

scholarly journals Application of an improved surface energy balance model to two large valley glaciers in the St. Elias Mountains, Yukon

2020 ◽  
pp. 1-16
Author(s):  
Tim Hill ◽  
Christine F. Dow ◽  
Eleanor A. Bash ◽  
Luke Copland
Keyword(s):  
Energy Balance ◽  
Surface Energy ◽  
Surface Energy Balance ◽  
Shortwave Radiation ◽  
Balance Model ◽  
Landsat 8 ◽  
Glacier Surface ◽  
Ice Dynamics ◽  
Surface Melt

Abstract Glacier surficial melt rates are commonly modelled using surface energy balance (SEB) models, with outputs applied to extend point-based mass-balance measurements to regional scales, assess water resource availability, examine supraglacial hydrology and to investigate the relationship between surface melt and ice dynamics. We present an improved SEB model that addresses the primary limitations of existing models by: (1) deriving high-resolution (30 m) surface albedo from Landsat 8 imagery, (2) calculating shadows cast onto the glacier surface by high-relief topography to model incident shortwave radiation, (3) developing an algorithm to map debris sufficiently thick to insulate the glacier surface and (4) presenting a formulation of the SEB model coupled to a subsurface heat conduction model. We drive the model with 6 years of in situ meteorological data from Kaskawulsh Glacier and Nàłùdäy (Lowell) Glacier in the St. Elias Mountains, Yukon, Canada, and validate outputs against in situ measurements. Modelled seasonal melt agrees with observations within 9% across a range of elevations on both glaciers in years with high-quality in situ observations. We recommend applying the model to investigate the impacts of surface melt for individual glaciers when sufficient input data are available.

scholarly journals Use of satellite and modeled soil moisture data for predicting event soil loss at plot scale

2015 ◽  
Vol 19 (9) ◽  
pp. 3845-3856 ◽  
Author(s):  
F. Todisco ◽  
L. Brocca ◽  
L. F. Termite ◽  
W. Wagner
Keyword(s):  
Soil Moisture ◽  
Soil Loss ◽  
Large Scale ◽  
Central Italy ◽  
Remote Sensing Data ◽  
Loss Estimation ◽  
Balance Model ◽  
Estimation Accuracy ◽  
Soil Losses

Abstract. The potential of coupling soil moisture and a Universal Soil Loss Equation-based (USLE-based) model for event soil loss estimation at plot scale is carefully investigated at the Masse area, in central Italy. The derived model, named Soil Moisture for Erosion (SM4E), is applied by considering the unavailability of in situ soil moisture measurements, by using the data predicted by a soil water balance model (SWBM) and derived from satellite sensors, i.e., the Advanced SCATterometer (ASCAT). The soil loss estimation accuracy is validated using in situ measurements in which event observations at plot scale are available for the period 2008–2013. The results showed that including soil moisture observations in the event rainfall–runoff erosivity factor of the USLE enhances the capability of the model to account for variations in event soil losses, the soil moisture being an effective alternative to the estimated runoff, in the prediction of the event soil loss at Masse. The agreement between observed and estimated soil losses (through SM4E) is fairly satisfactory with a determination coefficient (log-scale) equal to ~ 0.35 and a root mean square error (RMSE) of ~ 2.8 Mg ha−1. These results are particularly significant for the operational estimation of soil losses. Indeed, currently, soil moisture is a relatively simple measurement at the field scale and remote sensing data are also widely available on a global scale. Through satellite data, there is the potential of applying the SM4E model for large-scale monitoring and quantification of the soil erosion process.

scholarly journals “ISSUES TO IMPROVE WATER USE EFFICIENCY”

2021 ◽  
Vol 58 (1) ◽  
pp. 5508-5516
Author(s):  
Saukhanov Janibek Kazievish
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Balance Model ◽  
Optimal Solutions ◽  
Model Based ◽  
Use Efficiency ◽  
The Republic

This article evaluates the efficiency of water use in the Republic of Karakalpakstan by districts on the basis of specific coefficients. Optimal solutions to increase water use efficiency across regions have been developed on the basis of the intersectoral balance model. Based on the results of the analysis, conclusions and recommendations are provided.

An advanced error correction methodology for merging in-situ observed and model-based soil moisture

2018 ◽  
Vol 566 ◽  
pp. 150-163 ◽  
Author(s):  
Zhiyong Wu ◽  
Jianhong Zhou ◽  
Hai He ◽  
Qingxia Lin ◽  
Xiaotao Wu ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Error Correction ◽  
Model Based

scholarly journals Estimation of Ice Cream Mixture Viscosity during Batch Crystallization in a Scraped Surface Heat Exchanger

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 167 ◽  
Author(s):  
Alejandro De la Cruz Martínez ◽  
Rosa E. Delgado Portales ◽  
Jaime D. Pérez Martínez ◽  
José E. González Ramírez ◽  
Alan D. Villalobos Lara ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Control Strategies ◽  
Coupled Model ◽  
Ice Cream ◽  
Surface Heat ◽  
Model Based ◽  
Scraped Surface Heat Exchanger ◽  
Surface Heat Exchanger ◽  
Ice Fraction

Ice cream viscosity is one of the properties that most changes during crystallization in scraped surface heat exchangers (SSHE), and its online measurement is not easy. Its estimation is necessary through variables that are easy to measure. The temperature and power of the stirring motor of the SSHE turn out to be this type of variable and are closely related to the viscosity. Therefore, a mathematical model based on these variables proved to be feasible. The development of this mathematical relationship involved the rheological study of the ice cream base, as well as the application of a method for its in situ melting in the rheometer as a function of the temperature, and the application of a mathematical model correlating the SSHE stirring power and the ice cream viscosity. The result was a coupled model based on both the temperature and stirring power of the SSHE, which allowed for online viscosity estimation with errors below 10% for crystallized systems with a 30% ice fraction at the exit of the SSHE. The model obtained is a first step in the search for control strategies for crystallization in SSHE.

scholarly journals Evaluating the Drought Code Using In Situ Drying Timelags of Feathermoss Duff in Interior Alaska

Fire ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 25
Author(s):  
Eric Miller ◽  
Brenda Wilmore
Keyword(s):  
Water Balance ◽  
Evaporation Rate ◽  
Storage Capacity ◽  
Water Storage ◽  
Water Balance Model ◽  
Balance Model ◽  
Potential Evaporation ◽  
Water Storage Capacity ◽  
Interior Alaska

The Drought Code (DC) is a moisture code of the Canadian Forest Fire Weather Index System underlain by a hydrological water balance model in which drying occurs in a negative exponential pattern with a relatively long timelag. The model derives from measurements from an evaporimeter and no soil parameters are specified, leaving its physical nature uncertain. One way to approximate the attributes of a “DC equivalent soil” is to compare its drying timelag with measurements of known soils. In situ measurements of timelag were made over the course of a fire season in a black spruce-feathermoss forest floor underlain by permafrost in Interior Alaska, USA. On a seasonally averaged basis, timelag was 28 d. The corresponding timelag of the DC water balance model was 60 d. Water storage capacity in a whole duff column 200 mm deep was 31 mm. Using these figures and a relationship between timelag, water storage capacity, and the potential evaporation rate, a “DC equivalent soil” was determined to be capable of storing 66 mm of water. This amount of water would require a soil 366 mm deep, suggesting a revision of the way fire managers in Alaska regard the correspondence between soil and the moisture codes of the FWI. Nearly half of the soil depth would be mineral rather than organic. Much of the soil water necessary to maintain a 60 d timelag characteristic of a “DC equivalent soil” is frozen until after the solstice. Unavailability of frozen water, coupled with a June peak in the potential evaporation rate, appears to shorten in situ timelags early in the season.

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