A bodner-partom visco-plastic dynamic sphere benchmark problem

Developing benchmark analytic solutions for problems in solid and fluid mechanics is very important for the purpose of testing and verifying computational physics codes. Our primary objective in this research is to obtain a benchmark analytic solution to the equation of motion in radially symmetric spherical coordinates. An analytic solution for the dynamic response of a sphere composed of an isotropic visco-plastic material and subjected to spherically symmetric boundary conditions is developed and implemented. The radial displacement u is computed by solving the equation of motion, a linear second-order hyperbolic PDE. The plastic strains εp and εp are computed by solving two non-linear first-order ODEs in time. We obtain a solution for u in terms of the plastic strain components and boundary conditions in the form of an infinite series. Computationally, at each time step, we set up an iteration scheme to solve the PDE-ODE system. The linear momentum equation is solved using the plastic strains from the previous iteration, then the plastic strain equations are solved numerically using the new displacement. We demonstrate the accuracy and convergence of our benchmark solution under spatial mesh, time step, and eigenmode refinement

EVALUATION OF PRODUCTION-WELL PERFORMANCE IN RESPONSE TO FORMATION CLOGGING AND REHABILITATION FOR THE KEWEENAW BAY TRIBAL FISH HATCHERY

Temporally, the KBIC (Keweenaw Bay Indian Community) Hatchery wells have manifested general trends of declining specific capacity and higher energy consumption due to mineral precipitation in and around the production wells. Monitoring data, laboratory water analyses, and downhole video logging have confirmed that naturally occurring minerals are precipitating and clogging the screens and, likely, the surrounding formations. The reduction in fluid pressures in and around the well-screens from active pumping wells is typical but, ultimately alters the geochemical and physical conditions such that dissolved minerals precipitate on and around the well-screens, therefore, effectively clogging the well. The clogging from mineral precipitation results in increased drawdown causing more pressure losses and clogging, and so on. Consequently, the pumps work harder and ultimately increase energy consumption and reduce production efficiencies. The Hatchery’s SCADA system now provides the ability to monitor flows and drawdowns, which reflect important information regarding well field performance. To be more economically strategic in managing the well field operations it is apparent that the performance data from the SCADA system must be utilized to conserve well-field-related costs. The analysis of the SCADA data clearly shows that the production well’s performance diminishes with use over time due to well-screen plugging because of mineral precipitation in and around the well-screen. The observed regained performance from well rehabilitation efforts (mechanical scrubbing and/ or acid treatment) demonstrates their effectiveness, and with the use of the spreadsheet tool (developed for the KBIC Hatchery production well field), the frequency of rehabilitation efforts can be assessed on a more financially sound basis by forecasting a relative breakeven cost-benefit analysis for a particular well and associated rehabilitation. The economic analysis of power consumption and treatment costs suggests that well-treatment costs can be recovered in approximately 6-9 years based on the treatment\u27s effectiveness in offsetting the performance declination due to mineral precipitation from pumping and relative drawdown. In other words, the magnitude of the regained well performance will be proportional to the rehabilitation method’s effectiveness in removing the mineral precipitation buildup and unclogging the well screen. The SCADA system is invaluable for monitoring, understanding, and managing the well field. The continued use of the SCADA system and implementation of the other recommendations in this report will be financially beneficial as more informed flow-management decisions can be made with confidence. Furthermore, to improve life on our planet through more sustainable approaches to groundwater management, the continued development of computational tools that utilize field monitoring data in making strategic decisions for well rehabilitation and minimizing drawdown will be essential for groundwater optimization and energy cost reduction now and in the future

Integrating Real Practical Experience in ICT Education

An important challenge for advancing the quality of education in Information and Communication Technology (ICT) is to integrate education and practical experience. It is sensible to start such active learning already in an early stage of the curriculum, in a valuable, real-life, and effective manner. It is desirable to reach that goal in such a durable way that we can easily account for the continuous changes and extensions in the underlying ICT itself. This paper presents our experiences in integrating ICT education and practice from an educational designer\u27s point of view. We will give several hints on how to design such an integrated curriculum module. We first explicate which educational design questions deserve attention in designing such a module. For each such design question we present the solution we chose, some specific examples, our experiences over the years (gradually improving the organization of such a module), and alternative solutions there might be. We also give some quantitative information

The Chinese Steel Industry: Global Challenges in an Economic Perspective

The Chinese steel industry is an issue that elicits many interesting economic questions. My research will analyze the relationship between the quantity of Chinese steel imports and domestic prices for equivalent steel products in an effort to both ascertain the relationship and to emphasize the importance and relevance of understanding the structure and operation of the Chinese steel industry

Study of an engine flow diverter system for a large scale ejector powered aircraft model

Requirements were established for a conceptual design study to analyze and design an engine flow diverter system and to include accommodations for an ejector system in an existing 3/4 scale fighter model equipped with YJ-79 engines. Model constraints were identified and cost-effective limited modification was proposed to accept the ejectors, ducting and flow diverter valves. Complete system performance was calculated and a versatile computer program capable of analyzing any ejector system was developed

More hedging instruments may destabilize markets

This paper formalizes the idea that more hedging instruments may destabilize markets when traders are heterogeneous and adapt their behavior according to experience based reinforcement learning. We investigate three different economic settings, a simple mean-variance asset pricing model, a general equilibrium two-period overlapping generations model with heterogeneous expectations and a noisy rational expectations asset pricing model with heterogeneous information signals. In each setting the introduction of additional Arrow securities can destabilize the market, causing a bifurcation of the steady state to multiple steady states, periodic orbits or even chaotic fluctuations

If motion sounds: Movement sonification based on inertial sensor data

Within last years, movement sonification turned out to be an appropriate support for motor perception and motor control that can display physical motion in a very rich and direct way. But how should movement sonification be configured to support motor learning? The appropriate selection of movement parameters and their transformation into characteristic motion features is essential for an auditory display to become effective. In this paper, we introduce a real-time sonification framework for all common MIDI environments based on acceleration and orientation data from inertial sensors. Fundamental processing steps to transform motion information into meaningful sound will be discussed. The proposed framework of inertial motion capturing, kinematic parameter selection and possible kinematic acoustic mapping provides a basis for mobile real-time movement sonification which is a prospective powerful training tool for rehabilitation and sports and offers a broad variety of application possibilities.EU/EFRE/W2-8011866