Seismically Initiated Carbon Dioxide Gas Bubble Growth in Groundwater: A Mechanism for Co-seismic Borehole Water Level Rise and Remotely Triggered Secondary Seismicity

Visualization experiments, core-scale laboratory experiments, and numerical simulations were conducted to examine the transient effect of dilational seismic wave propagation on pore fluid pressure in aquifers hosting groundwater that is near saturation with respect to dissolved carbon dioxide (CO2) gas. Groundwater can become charged with dissolved CO2 through contact with gas-phase CO2 in the Earth's crust derived from magma degasing, metamorphism, and biogenic processes. The propagation of dilational seismic waves (e.g., Rayleigh and p-waves) causes oscillation of the mean normal confining stress and pore fluid pressure. When the amplitude of the pore fluid pressure oscillation is large enough to drive the pore fluid pressure below the bubble pressure, an aqueous-to-gas-phase transition can occur in the pore space, which causes a buildup of pore fluid pressure and reduces the inter-granular effective stress under confined conditions. In visualization experiments conducted in a Hele-Shaw cell representing a smooth-walled, vertically oriented fracture, millisecond-scale pressure perturbations triggered bubble nucleation and growth lasting tens of seconds, with resulting pore fluid overpressure proportional to the magnitude of the pressure perturbation. In a Berea sandstone core flooded with initially under-saturated aqueous CO2 under conditions representative of a confined aquifer, rapid reductions in confining stress triggered transient pore pressure rise up to 0.7 MPa (100 psi) overpressure on a timescale of ~10 hours. The rate of pore pressure buildup in the first 100 seconds was proportional to the saturation with respect to dissolved CO2 at the pore pressure minimum. Sinusoidal confining stress oscillations on a Berea sandstone core produced excess pore fluid pressure after the oscillations were terminated. Confining stress oscillations in the 0.1-0.4 MPa (15-60 psi) amplitude range and 0.05-0.30 Hz frequency band increased the pore fluid pressure by 13-60 cm of freshwater. Co-seismic borehole water level increases of the same magnitude were observed in Parkfield, California, and Long Valley caldera, California, in response to the propagation of a Rayleigh wave in the same amplitude and frequency range produced by the June 28, 1992 MW 7.3 Landers, California, earthquake. Co-seismic borehole water level rise is well documented in the literature, but the mechanism is not well understood, and the results of core-scale experiments indicate that seismically initiated CO2 gas bubble nucleation and growth in groundwater is a reasonable mechanism. Remotely triggered secondary seismicity is also well documented, and the reduction of effective stress due to CO2 bubble nucleation and growth in critically loaded faults may potentially explain how, for example, the June 28, 1992 MW 7.3 Landers, California, earthquake triggered seismicity as far away as Yellowstone, Wyoming, 1250 km from the hypocenter. A numerical simulation was conducted using Euler's method and a first-order kinetic model to compute the pore fluid pressure response to confining stress excursions on a Berea sandstone core flooded with initially under-saturated aqueous CO2. The model was calibrated on the pore pressure response to a rapid drop and later recovery of the confining stress. The model predicted decreasing overpressure as the confining stress oscillation frequency increased from 0.05 Hz to 0.30 Hz, in contradiction with the experimental results and field observations, which exhibit larger excess pore fluid pressure in response to higher frequency oscillations. The limitations of the numerical model point to the important influence of non-ideal behavior arising from a discontinuous gas phase and complex dynamics at the gas-liquid interface

Telecommunications Course Content: Input from Information Technology Professionals

Preparing students to be competent in the Information Technology (IT) world is a goal of technology-based departments in colleges and universities. Telecommunications is one part of the IT area in which students need to be prepared. Many colleges and universities teach telecommunications courses at different levels or incorporate telecommunications topics in more than one course. This, along with the challenge of keeping up with an ever-changing information technology environment, provides a challenge to academicians. Seeking input from IT professionals is one way to help keep curricula current. This research is an extension of a 1997 Delphi study dealing with telecommunications course content for a beginning telecommunications course at the college or university level. The 1997 participants were members of the Organizational Systems Research Association (OSRA) and had either taught telecommunications topics and/or researched in the area. The final course content topics and subtopics from the 1997 study served as Round one data for the participants of this 2003 Delphi study. The participants were members of the Association of Information Technology Professionals (AITP). This study identifies the common consent (two-thirds of the participants rating the topics/subtopics with a 5 - Definitely Do Include the Topic) and the consensus (all participants rating the topics/subtopics with a 5) course content lists for a telecommunications course taught at the college/university level

The Great CSU Weed of 2019

We kicked. We screamed. We coped. We survived. We will tell you how. In early 2019, The Columbus State University Schwob Memorial (Main) library faced a MASSIVE weeding project like nothing they had coped with before. In this presentation, two librarians, Amy Parsons from Technical services and Emily Crews from Reference services, will share their workflows, public relations challenges, a few best practices, and changes that will be implemented. Oftentimes, libraries have to be torn apart to build them back better. This will be a lighthearted conversation on how we handled this challenge. We will also share a fall update on where we are now in the renovation process

Comparison of Communication Skills Needed by Information Systems Undergraduates and Graduates as Perceived by Information Systems Professionals

Throughout information systems research, it is common to find studies examining necessary computer skills needed for information systems positions. However, a trend has appeared in studies showing a decrease in the employers\u27 desire for computer literacy skills and a greater emphasis on communications skills. This study involving 500 Association of Information Technology Professionals determined the top five communication skills needed by information systems undergraduates and graduates in each of three communication areas. The three areas researched were written, oral, and interpersonal communication skills. The top three ranked communication skills for undergraduate students were writing clear directions and instructions, giving clear directions and instructions orally, and listening effectively. The top three ranked communication skills for graduate students were writing analytical reports, directing a meeting, and listening effectively. These skills should be implemented into the undergraduate and graduate curricula of information systems programs

Interdisciplinary Education Outreach with Traffic Sensor Build Kits

The goal of this project was to attract K-12 students to transportation engineering careers through STEM outreach programs. To accomplish this goal, the object of the project was to design and implement maritime freight oriented educational outreach activities centered on traffic sensing technologies for middle, high school, and first-year college students. In MarTREC Project 5011 (Evaluating the Performance of Intermodal Connectors), the research team designed a low-cost, easily implementable LiDAR and Bluetooth sensor bundle that was capable of detecting, characterizing, and tracking freight trucks as they traveled to and from inland waterway port areas. The sensor provided data necessary to measure port performance and roadway usage by industry. This project re-designed the sensor bundle as an educational outreach activity by creating sensor build kits and associated lesson plans for middle school, high school, and first year university students. The concept of the build kits as a tool was highly praised when presented by the PI to professionals at the Missouri Valley Institute of Transportation Engineers (MOVITE) fall meeting in 2017.https://scholarworks.uark.edu/cveglearn/1000/thumbnail.jp

Tension perpendicular to grain strength of wood, Laminated Veneer Lumber (LVL), and Cross-Banded LVL (LVL-C)

Recent experimental tests carried out on structural timber members have highlighted the importance of tension perpendicular to grain strength, particularly in beams with holes and notches, in connection regions, in curved beams, and in post-tensioned timber frames. Innovative engineered wood products such as Cross Banded Laminated Veneer Lumber (LVL-C) have been introduced into the market specifically to improve the perpendicular to grain properties of normal Laminated Veneer Lumber (LVL). This paper reports on tests that were performed at the University of Canterbury using specimens of sawn timber Radiata Pine, LVL and LVL-C. The perpendicular to grain tension strengths of LVL was generally lower than those for sawn timber, but the LVL-C showed a significantly improved strength. The paper also compares the experimental results with strengths predicted using both coupled elastic Finite Element Method (FEM) and Linear Elastic Fracture Mechanics (LEFM) models. These models were found to predict the average strength with reasonable accuracy. © 2011 Taylor & Francis Group, London

Development of Protacs to Target Cancer-promoting Proteins for Ubiquitination and Degradation

The proteome contains hundreds of proteins that in theory could be excellent therapeutic targets for the treatment of human diseases. However, many of these proteins are from functional classes that have never been validated as viable candidates for the development of small molecule inhibitors. Thus, to exploit fully the potential of the Human Genome Project to advance human medicine, there is a need to develop generic methods of inhibiting protein activity that do not rely on the target protein’s function. We previously demonstrated that a normally stable protein, methionine aminopeptidase-2 or MetAP-2, could be artificially targeted to an Skp1-Cullin-F-box (SCF) ubiquitin ligase complex for ubiquitination and degradation through a chimeric bridging molecule or Protac (proteolysis targeting chimeric molecule). This Protac consisted of an SCFß-TRCP-binding phosphopeptide derived from I{kappa}B{alpha} linked to ovalicin, which covalently binds MetAP-2. In this study, we employed this approach to target two different proteins, the estrogen (ER) and androgen (AR) receptors, which have been implicated in the progression of breast and prostate cancer, respectively. We show here that an estradiol-based Protac can enforce the ubiquitination and degradation of the {alpha} isoform of ER in vitro, and a dihydroxytestosterone-based Protac introduced into cells promotes the rapid disappearance of AR in a proteasome-dependent manner. Future improvements to this technology may yield a general approach to treat a number of human diseases, including cancer

Ultimate performance of timber connection with normal screws

This paper presents the results of experimental push-out tests on two different types of timber composite connections using only normal screws as the shear connecter. The push out tests were conducted based on Eurocode 5 recommendations and the load-slip responses obtained from lab tests are used to determine the stiffness of the connections at serviceability, ultimate and near collapse levels, and the performance of the connections are assessed at ultimate load. Moreover, an analytical model is derived for each type of connection based on the experimental results and using a non linear regression, which can be implemented into non-linear FE analysis of timber beams with normal screws. © 2013 Taylor & Francis Group

Application of the damage index method for plate-like structures to timber bridges

The paper presents a research recently completed by the authors utilizing a method of damage evaluation for identifying damage in timber bridges, numerically and experimentally. The method utilizes changes in modal strain energy between the undamaged and damaged states of plate-like structures. A finite element model of a laboratory timber bridge was developed to investigate the capabilities and limitations of the method to detect damage. A simple four-girder bridge was fabricated and tested in a laboratory to verify the method. The numerical studies showed that the method can correctly identify single and multiple damage locations within the bridge. The experimental studies also showed promising results for detecting severe damage, but less effective for light and medium damage. Copyright © 2009 John Wiley & Sons, Ltd

Stochastic deterioration processes for bridge lifetime assessment

The Markov chain model can be found in the maintenance and repair problems since the early 60's, is introduced to the maintenance of road infrastructure in the 1980's, and is made to drive the current bridge maintenance optimization systems. While this model results into solvable programming problems and provides a solution, there are a number of criticisms associated with it. In this article, we highlight the shortfalls of the Markov model for bridge infrastructure lifetime assessment and promote the use of stochastic processes. We use examples from a study for the modeling of the condition of bridges that considers more than 15 years of data. We argue for the applicability of the gamma process and other stochastic processes. © 2008 IEEE