CONSTANT HEAD PERMEAMETER FORMULA DEPENDENCE ON ALPHA PARAMETER

1997 ◽  
Vol 40 (5) ◽  
pp. 1377-1379 ◽  
Author(s):  
D. D. Bosch
Keyword(s):  
Constant Head

Effects of Inclination Angle on Archimedes Screw Generator Power Production with Constant Head

2021 ◽  
Vol 147 (3) ◽  
pp. 04021001
Author(s):  
Scott Simmons ◽  
Guilhem Dellinger ◽  
Murray Lyons ◽  
Abdelali Terfous ◽  
Abdellah Ghenaim ◽  
...  
Keyword(s):  
Inclination Angle ◽  
Power Production ◽  
Constant Head

Virus transport from drywells under constant head conditions: A modeling study

2021 ◽  
Vol 197 ◽  
pp. 117040
Author(s):  
Salini Sasidharan ◽  
Scott A. Bradford ◽  
Jiří Šimůnek ◽  
Stephen R. Kraemer
Keyword(s):  
Virus Transport ◽  
Constant Head ◽  
Modeling Study

scholarly journals Water Distribution from Artificial Recharge via Infiltration Basin under Constant Head Conditions

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1052
Author(s):  
Tiansong Qi ◽  
Longcang Shu ◽  
Hu Li ◽  
Xiaobo Wang ◽  
Yanqing Men ◽  
...  
Keyword(s):  
Vadose Zone ◽  
Water Distribution ◽  
Artificial Recharge ◽  
Buffer Zone ◽  
Experimental Conditions ◽  
Correlation And Regression Analysis ◽  
Infiltration Basin ◽  
Constant Head ◽  
3D Software

The vadose zone plays a significant role during artificial recharge via the infiltration basin. Its thickness, lithology, heterogeneity, among others greatly affect the recharge efficiency. The main objective of this research is to establish the role of the vadose zone and the impacts of infiltration basin features and vadose zone factors on water distributions. In this work, an ideal conceptual model was considered, and mathematical models were built using HYDRUS (2D/3D) software package version 2.05. A total of 138 numerical experiments were implemented under seven types of experimental conditions. The experimental data were analyzed with the aid of correlation and regression analysis. The results showed that infiltration basin features and vadose zone factors had various impacts on water distribution, low permeability formation had various effects on evaporation depending on its depth, and there were consistent, similar, or different variation trends between infiltration and recharge. In conclusion, it is recommended that when the vadose zones are to be chosen as an infiltration basin site, the trade-off among the infiltration, recharge, storage, and evaporation should be seriously considered. This paper may contribute to a better understanding of the vadose zone as a buffer zone for artificial recharge.

Using constant head step tests to determine hydraulic apertures in fractured rock

2011 ◽  
Vol 126 (1-2) ◽  
pp. 85-99 ◽  
Author(s):  
Patryk M. Quinn ◽  
Beth L. Parker ◽  
John A. Cherry
Keyword(s):  
Fractured Rock ◽  
Constant Head

The Effect of Head Tilt on Perception of Self-Orientation While in a Greater than One G Environment

1995 ◽  
Vol 5 (1) ◽  
pp. 1-17
Author(s):  
Tamara L. Chelette ◽  
Eric J. Martin ◽  
William B. Albery
Keyword(s):  
Dynamic Environment ◽  
Head Tilt ◽  
Nonlinear Function ◽  
Longitudinal Axis ◽  
Multiple Regression Model ◽  
The Body ◽  
Hand Position ◽  
Haptic Information ◽  
Perception Of Self ◽  
Constant Head

The effect of head tilt on the perception of self-orientation while in a greater than one G environment was studied in nine subjects using the Armstrong Laboratory Dynamic Environment Simulator. After a 12-s stabilization period at a constant head tilt and G level, subjects reported their perception of the horizon by placing their right hand in a position they believed to be horizontal. Head tilt conditions ranged from -30° to +45° pitch over each of three head yaw positions. G levels ranged from one to four and were in the longitudinal axis of the body (Gz). Hand position was recorded in both the pitch and roll body axes. A function of head tilt did improve the fit of a multiple regression model to the collected data in both the pitch and roll axes (P < .05). The best fit was accomplished with a nonlinear function of G and head pitch. When the head remained level but the environment tilted with respect to the G vector (at angles similar to those perceived during head tilt), subjects accurately reported the environmental tilt. Head tilt under G can result in vestibular-based illusionary perception of environmental tilt. Actual environmental tilt is accurately perceived due to added channels of haptic information.

scholarly journals Comparison of three measurement methods of saturated hydraulic condutivity

2006 ◽  
Vol 3 (3) ◽  
pp. 987-1019 ◽  
Author(s):  
C. Fallico ◽  
E. Migliari ◽  
S. Troisi
Keyword(s):  
Hydraulic Conductivity ◽  
Measurement Method ◽  
Sandy Loam ◽  
Measurement Methods ◽  
Soil Core ◽  
Statistical Parameters ◽  
Factors Affecting ◽  
Average Value ◽  
Constant Head ◽  
Log Normal

Abstract. After pointing out the importance of the saturated hydraulic conductivity (ks) measurements and the difficulties and uncertainties that are present, and after recalling salient aspects of three well-known measurement methods of this parameter (i.e. constant-head tension infiltrometer (TI) method, constant-head pressure infiltrometer (PI) method and soil core (SC) estimates method), the results of an investigation on data which were obtained during a measurement campaign on an area of 800 m2, on a sandy loam hillslope, located in Southern Italy, were carried out again here. Three sets of values of ks, obtained with these measurement methods, were analyzed statistically, verifying that the log-normal distribution describes these better than the normal one; moreover, the more significant statistical parameters of each set were compared (average value , amplitude A, coefficient of variation CV and standard deviation SD), individualizing the more significant differences. The greatest value of hydraulic conductivity was found with method (PI), while the smallest with (SC) and the intermediate with (TI); these differences were translated into macroporosity and into the influence of the single measurement method. Moreover, referring to the possible factors affecting the results, the importance can be noted of the structure, the texture and the soil events, in terms of utilization, which can affect the measure of ks leading often to very different values even for similar soils, but with a different history, independently of the coincidence of the measurement points and they can be determining to explain the differences affecting the results obtained in analogous investigations by other researchers. Having confirmed that generalization is not possible, the need was emphasized to adopt the necessary devices relating to the specific measurement method, case by case, and to carefully explain the obtained results, in the light of the peculiarities and the limits of each situation. Finally, the results of similar statistical analysis carried out on a greater number of ks values, measured through the (TI) and (PI) methods are shown in this paper, with some statistical considerations on the increasing of the measurements number.

scholarly journals Hydrogeological Conceptual Model in the Middle of Randublatung Groundwater Basin

2021 ◽  
Vol 926 (1) ◽  
pp. 012078
Author(s):  
D L Setyaningsih ◽  
K D Setyawan ◽  
D P E Putra ◽  
Salahuddin
Keyword(s):  
Groundwater Flow ◽  
Conceptual Model ◽  
Unconfined Aquifer ◽  
Primary Data ◽  
Essential Information ◽  
Aquifer System ◽  
The North ◽  
Shallow Wells ◽  
Groundwater Basin ◽  
Constant Head

Abstract Randublatung groundwater basin is one of the groundwaters basins with massive utilization of groundwater pumping. However, the knowledge of the comprehensive hydrogeological system in this groundwater basin is limited, so this research aims to determine a comprehensive hydrogeological conceptual model of the Randublatung groundwater basin. The methodology was conducted by collecting secondary and primary data of deep and shallow wells to evaluate boundaries of pattern and direction of groundwater flow and develop the aquifer system’s geometry. The result shows that the groundwater flow boundaries are Grogol River in the west, Wado River in the East, Bengawan Solo river in the South as a river boundary, and Rembang Mountains in the North as a constant head boundary. Therefore, groundwater flows from the hills area to the Bengawan Solo River and the north as the river’s flow. Based on the log bor evaluation, the aquifer system of the study area consist of an unconfined aquifer with a maximum thickness of 20 m and three layers of confined aquifers with thickness vary between 8 to 60 m. the hydraulic conductivity of the aquifers depends on the aquifer’s lithology range from sand, gravel, limestone, and sandstone. This hydrogeological conceptual model provides essential information for numerical groundwater models in the middle of the Randublatung groundwater basin.

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