Dual-Permeability Modeling of Capillary Diversion and Drift Shadow Effects in Unsaturated Fractured Rock

2009 ◽  
Vol 131 (10) ◽  
Author(s):  
Clifford K. Ho ◽  
Bill W. Arnold ◽  
Susan J. Altman

The drift-shadow effect describes capillary diversion of water flow around a drift or cavity in porous or fractured rock, resulting in lower water flux directly beneath the cavity. This paper presents computational simulations of drift-shadow experiments using dual-permeability models, similar to the models used for performance assessment analyses of flow and seepage in unsaturated fractured tuff at Yucca Mountain. Comparisons were made between the simulations and experimental data from small-scale drift-shadow tests. Results showed that the dual-permeability models captured the salient trends and behavior observed in the experiments, but constitutive relations (e.g., fracture capillary-pressure curves) can significantly affect the simulated results. Lower water flux beneath the drift was observed in both the simulations and tests, and fingerlike flow patterns were seen to exist with lower simulated capillary pressures. The dual-permeability models used in this analysis were capable of simulating these processes. However, features such as irregularities along the top of the drift (e.g., from roof collapse) and heterogeneities in the fracture network may reduce the impact of capillary diversion and drift shadow. An evaluation of different meshes showed that at the grid refinement used, a comparison between orthogonal and unstructured meshes did not result in large differences.

2020 ◽  
Author(s):  
Ryan Haagenson ◽  
Harihar Rajaram

<p>It has been long understood that the injection of fluids into the subsurface, a common practice in several industries, often leads to seismic activity by altering the fluid pressures and stress states acting along fault structures. In some cases, this puts the people and infrastructure located nearby at considerable risk. The effective mitigation of this potential hazard relies heavily on understanding the physical mechanisms controlling the behavior of injection-induced seismicity. Here, we aim to better understand the spatiotemporal patterns of the seismicity through the concept of triggering fronts (i.e. the propagating front where the onset of seismicity occurs). Previously, triggering fronts have been studied mostly in the context of homogenous porous media. Here, field scale simulations of fluid injection into fractured rock are modeled as linear, uncoupled fluid flow. While injection-induced seismicity is certainly affected by poroelastic stressing and nonlinear hydraulic parameters of the rock, the focus of this study is to understand the impact of a discrete fracture network on patterns of seismicity. Therefore, poroelastic and nonlinear effects are ignored. Results indicate that the pathways of high permeability within the fracture network greatly influence the migration of the triggering front. While the triggering front clearly follows a diffusive process as expected, the corresponding diffusivity is found to be distinct from the effective hydraulic diffusivity of the domain. We, therefore, call this diffusivity the seismic diffusivity of the fractured rock. Understanding seismic diffusivity may help us better interpret datasets of injection-induced seismicity and potentially forecast the patterns of injection-induced seismicity in well-characterized formations.</p>


2015 ◽  
Vol 3 (1) ◽  
pp. 31 ◽  
Author(s):  
Rohani Mohd ◽  
Badrul Hisham Kamaruddin ◽  
Khulida Kirana Yahya ◽  
Elias Sanidas

The purpose of the present study is twofold: first, to investigate the true values of Muslim owner managers; second, to examine the impact of these values on entrepreneurial orientations of Muslim small-scale entrepreneurs. 850 Muslim owner managers were selected randomly using the sampling frame provided by MajlisAmanah Rakyat Malaysia (MARA). 162 completed questionnaires were collected and analyzed. For this paper only two dimensions of entrepreneurial orientations were analyzed: proactive orientation and innovative orientation. Interestingly, the findings revealed that Muslim businessmen/women are honest, loyal, disciplined and hard working. Loyalty and honesty are positively related to proactive orientation, while discipline and hard-work are positively related to innovative orientation. The findings provide implications for existing relevant theories, policy makers, practitioners and learning institutions. 


2020 ◽  
Vol 11 (SPL1) ◽  
pp. 796-806
Author(s):  
Sana M Kamal ◽  
Ali Al-Samydai ◽  
Rudaina Othman Yousif ◽  
Talal Aburjai

COVID-19 pandemic has spread across the world, which considered a relative of the severe acute respiratory syndrome (SARS), with possibility of transmission from animals to human and effect each of health and economic. Several preventative strategies and non-pharmaceutical interventions have been used to slow down the spread of COVID-19. The questionnaire contained 36 questions regarding the impact of COVID-19 quarantine on children`s behaviors and language have been distributed online (Google form). Data collected after asking parents about their children behavior during quarantine, among the survey completers (n=469), 42.3% were female children, and 57.7 were male children. Results showed that quarantine has an impact on children`s behaviors and language, where stress and isolationism has a higher effect, while social relations had no impact. The majority of the respondents (75.0%) had confidence that community pharmacies can play an important role in helping families in protection their children`s behaviors and language as they made the highest contact with pharmacists during quarantine. One of the main recommendations that could be applied to help parents protection and improvement their children`s behaviors and language in quarantine condition base on simple random sample opinion is increasing the role of community pharmacies inpatient counseling and especially towards children after giving courses to pharmacists in child psychology and behavior. This could be helpful to family to protect their children, from any changing in them behaviors and language in such conditions in the future if the world reface such the same problem.


2020 ◽  
Vol 3 (1) ◽  
pp. 130-135
Author(s):  
Mukhiddin Tursunmuratov ◽  

This article provides a detailed description and explanation of the term "popular culture". It also analyzes a number of aspects of "popular culture" that are becoming more widespread today, their role and influence in the formation of the minds and behavior of young people, and draws the necessary conclusions. Most importantly, it also describes ways to protect young people from threats in the form of "popular culture" that negatively affect their morale.


2020 ◽  
Vol 56 (2) ◽  
pp. 119-122
Author(s):  
Doris Adams Hill ◽  
Theoni Mantzoros ◽  
Jonté C. Taylor

Special educators are often considered the experts in their school when it comes to developing functional behavior assessments (FBA) and behavior intervention plans (BIP), yet rarely are they trained much beyond basic antecedents, behaviors, and consequences (ABC). This column discusses concepts that will expand special education professionals’ knowledge to make better decisions regarding interventions for the students they serve. Specifically, the focus is on motivating operations (MO) and function-based interventions and the implications of these on behavior. Knowledge of the concept of MOs can enhance a teacher’s ability to provide evidence-based interventions and more fully developed behavioral interventions for students in their purview.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4658
Author(s):  
Artur Guzy ◽  
Wojciech T. Witkowski

Land subsidence caused by groundwater withdrawal induced by mining is a relatively unknown phenomenon. This is primarily due to the small scale of such movements compared to the land subsidence caused by deposit extraction. Nonetheless, the environmental impact of drainage-related land subsidence remains underestimated. The research was carried out in the “Bogdanka” coal mine in Poland. First, the historical impact of mining on land subsidence and groundwater head changes was investigated. The outcomes of these studies were used to construct the influence method model. With field data, our model was successfully calibrated and validated. Finally, it was used for land subsidence estimation for 2030. As per the findings, the field of mining exploitation has the greatest land subsidence. In 2014, the maximum value of the phenomenon was 0.313 cm. However, this value will reach 0.364 m by 2030. The spatial extent of land subsidence caused by mining-induced drainage extends up to 20 km beyond the mining area’s boundaries. The presented model provided land subsidence patterns without the need for a complex numerical subsidence model. As a result, the method presented can be effectively used for land subsidence regulation plans considering the impact of mining on the aquifer system.


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