Geological Engineering Commons^™

Wetting-Driven Formation Of Present-Day Loess Structure, Yanrong Li, Weiwei Zhang, Shengdi He, Adnan Aydin

Faculty and Student Publications

© 2020 The Authors Present-day loess, especially Malan loess formed in Later Quaternary, has a characteristic structure composed of vertically aligned strong units and weak segments. Hypotheses describing how this structure forms inside original loess deposits commonly relate it to wetting-drying process. We tested this causal relationship by conducting unique experiments on synthetic samples of initial loess deposits fabricated by free-fall of loess particles. These samples were subjected to a wetting-drying cycle, and their structural evolutions were documented by close-up photography and CT scanning. Analysis of these records revealed three key stages of structural evolution: initiation (evenly distributed cracks appear …

A Mathematical Framework For Estimating Risk Of Airborne Transmission Of Covid-19 With Application To Face Mask Use And Social Distancing, Rajat Mittal, Charles Meneveau, Wen Wu

Faculty and Student Publications

© 2020 Author(s). A mathematical model for estimating the risk of airborne transmission of a respiratory infection such as COVID-19 is presented. The model employs basic concepts from fluid dynamics and incorporates the known scope of factors involved in the airborne transmission of such diseases. Simplicity in the mathematical form of the model is by design so that it can serve not only as a common basis for scientific inquiry across disciplinary boundaries but it can also be understandable by a broad audience outside science and academia. The caveats and limitations of the model are discussed in detail. The model …

A Comparison Study Using Particle Swarm Optimization Inversion Algorithm For Gravity Anomaly Interpretation Due To A 2d Vertical Fault Structure, Neil Lennart Anderson, Khalid S. Essa, Mahmoud Elhussein

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

A new approach to the inversion of gravity data utilizing the Particle Swarm Optimization (PSO) algorithm is used to model 2D vertical faults. The PSO algorithm is stochastic in nature; its development was motivated by the communal in-flight performance of birds looking for food. The birds are represented by particles (or models). Individual particles have a location and a velocity vector. The location vectors represent the parameter value. PSO is adjusted with random particles (models) and searches for targets by updating generations. Herein, the PSO algorithm is applied to three synthetic data sets (residual only with and without noise, residual …

Desarrollo De Un Esquema De Gestión Hídrica En El Sistema Acuífero Sap 3.1 Apoyado De La Tipificación De Suelos Y El Modelo Conceptual De Thöt, Maria Camila Soriano Espinosa, Camilo José Rodríguez Carvajal

Ingeniería Ambiental y Sanitaria

El presente proyecto tiene como objetivo principal desarrollar un esquema de gestión hídrica (EGH) en el sistema acuífero SAP 3.1, provincia llanos orientales, con base en la tipificación de suelos y el modelo conceptual de Tӧth, partiendo de que las aguas subterráneas se consideran una fuente alternativa de abastecimiento por su mejor calidad y el bajo costo de manejo en comparación al agua superficial, y teniendo en cuenta que el Departamento del Meta conoce la riqueza hídrica que está en su jurisdicción, no cuenta con una regulación adecuada en pro de una gestión hídrica a nivel subterráneo. La metodología empleada …

Load-Balancing Rendezvous Approach For Mobility-Enabled Adaptive Energy-Efficient Data Collection In Wsns, Jian Zhang, Jian Tang, Zhonghui Wang, Feng Wang, Gang Yu

Faculty and Student Publications

Copyright © 2020 KSII The tradeoff between energy conservation and traffic balancing is a dilemma problem in Wireless Sensor Networks (WSNs). By analyzing the intrinsic relationship between cluster properties and long distance transmission energy consumption, we characterize three node sets of the cluster as a theoretical foundation to enhance high performance of WSNs, and propose optimal solutions by introducing rendezvous and Mobile Elements (MEs) to optimize energy consumption for prolonging the lifetime of WSNs. First, we exploit an approximate method based on the transmission distance from the different node to an ME to select suboptimal Rendezvous Point (RP) on the …

Revisiting Lightweight Encryption For Iot Applications: Error Performance And Throughput In Wireless Fading Channels With And Without Coding, Yazid M. Khattabi, Mustafa M. Matalgah, Mohammed M. Olama

Faculty and Student Publications

© 2013 IEEE. Employing heavy conventional encryption algorithms in communications suffers from added overhead and processing time delay; and in wireless communications, in particular, suffers from severe performance deterioration (avalanche effect) due to fading. Consequently, a tremendous reduction in data throughput and increase in complexity and time delay may occur especially when information traverse resource-limited devices as in Internet-of-Things (IoT) applications. To overcome these drawbacks, efficient lightweight encryption algorithms have been recently proposed in literature. One of those, that is of particular interest, requires using conventional encryption only for the first block of data in a given frame being transmitted. …

Cooperative Relay Selection For Load Balancing With Mobility In Hierarchical Wsns: A Multi-Armed Bandit Approach, Jian Zhang, Jian Tang, Feng Wang

Faculty and Student Publications

© 2013 IEEE. Energy efficiency is the major concern in hierarchical wireless sensor networks(WSNs), where the major energy consumption originates from radios for communication. Due to notable energy expenditure of long-range transmission for cluster members and data aggregation for Cluster Head (CH), saving and balancing energy consumption is a tricky challenge in WSNs. In this paper, we design a CH selection mechanism with a mobile sink (MS) while proposing relay selection algorithms with multi-user multi-armed bandit (UM-MAB) to solve the problem of energy efficiency. According to the definition of node density and residual energy, we propose a conception referred to …

Timcc: On Data Freshness In Privacy-Preserving Incentive Mechanism Design For Continuous Crowdsensing Using Reverse Auction, Xiaoqiang Ma, Weiwei Deng, Feng Wang, Menglan Hu, Fei Chen, Mohammad Mehedi Hassan

Faculty and Student Publications

© 2013 IEEE. As an emerging paradigm that leverages the wisdom and efforts of the crowd, mobile crowdsensing has shown its great potential to collect distributed data. The crowd may incur such costs and risks as energy consumption, memory consumption, and privacy leakage when performing various tasks, so they may not be willing to participate in crowdsensing tasks unless they are well-paid. Hence, a proper privacy-preserving incentive mechanism is of great significance to motivate users to join, which has attracted a lot of research efforts. Most of the existing works regard tasks as one-shot tasks, which may not work very …

Data Analytics Of Natural Gas Injection Enhanced Oil Recovery For Unconventional Reservoirs, Ali Waqar

Masters Theses

"Unconventional Enhanced Oil recovery, via the injection of natural gas has attracted great attention, as studies and projects have shown to be promising. An overview of pertinent studies has been carried out. Core Scale Laboratory Experiments, Core Scale Simulation, Field Scale simulation and pilot projects are analyzed. Data is collected for Core, Reservoir, Operational, and recovery information. Thereafter, Data analysis techniques are applied to identify data ranges, distributions, trends, relationships, and to eventually reach conclusions.

Huff and Puff injection is the preferred mode of injection, delivering most promising results for unconventional reservoirs. Across all the studies, with increase in amount …

Comparative Study Of Gross Split And Cost Recovery Production Sharing Contracts In Indonesia, Mohammad Ubaidillah

Chulalongkorn University Theses and Dissertations (Chula ETD)

In upstream oil and gas business, Indonesian has introduced Production Sharing Contract Cost Recovery (PSC CR) in 1966 and still implementing that fiscal system until nowadays. In January 2017, The Indonesian Minister of Energy and Mineral Resources (MEMR or ESDM) introduce new PSC system called Production Sharing Contract Gross Split (PSC GS) following with three amendments until 2019. Ministries believe this new Fiscal regime can attract more investor to invest Oil & Gas business in Indonesia by delivering three main values which are certainty, efficiency, and simplicity policies. This study evaluates and compares the financial aspect of new Indonesian fiscal …

An Integrated Wellbore Stability Study To Mitigate Expensive Wellbore Instability Problems While Drilling Into Zubair Shale/Sand Sequence, Southern Iraq, Ahmed Khudhair Abbas

Doctoral Dissertations

”The Zubair Formation is the most prolific reservoir in Iraq, which is comprised of sandstones interbedded with shale sequences. Due to the weak nature of the shale sequence, the instability of a wellbore is one of the most critical challenges that continuously appears during drilling across this formation. Historically, over 90% of wellbore problems in the Zubair Formation were due to wellbore instability. Problems associated with wellbore instability, such as tight hole, shale caving, stuck logging tools along with subsequent fishing, stuck pipe, and sidetracking result in increasing the non-productive time. This non-productive time has cost an enormous amount of …