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A Possible Pathway For High School Science In A Stem World, Cary Sneider 2011 Utah State University

A Possible Pathway For High School Science In A Stem World, Cary Sneider

Publications

Today‘s high school science teachers find themselves in a period of transition. For the past decade there have been calls for replacing a narrow focus on science education—the traditional courses in physics, chemistry, biology, and Earth and space science—with a broader curriculum on STEM (that is, the four allied fields of science, technology, engineering, and mathematics). However, at present there are no guidelines on what that broader curriculum should include or how it should be designed, and the gulf that has separated science and mathematics seems as wide as ever, despite decades of efforts to bridge the ...


Design Principles For High School Engineering Design Challenges: Experiences From High School Science Classrooms, Christian Schunn 2011 Utah State University

Design Principles For High School Engineering Design Challenges: Experiences From High School Science Classrooms, Christian Schunn

Publications

At the University of Pittsburgh, we have been exploring a range of approaches to design challenges for implementation in high school science classrooms (Apedoe, Reynolds, Ellefson, & Schunn, 2008; Ellefson, Brinker, Vernacchio, & Schunn, 2008; Schunn, Silk, & Apedoe, in press). In general, our approach has always involved students working during class time over the course of many weeks. So, our understanding of what works must be contextualized to that situation (i.e., without significant home support, by students enrolled in traditional classrooms, involving content that is connected to traditional science classrooms). However, our approach has been implemented with thousands of students in over 80 classrooms ranging from 9th grade biology or general science to 11th grade physics, from traditional mainstream science classrooms to elective Biology II or Honors Chemistry, and from high needs urban classrooms to affluent suburban classrooms. In other words, there is some important generality to these experiences. We have also conducted a number of studies on students in these settings, to understand a range of factors that influence student learning and affect outcomes (Apedoe & Schunn, 2009; Doppelt & Schunn, 2008; Reynolds, Mehalik, Lovell, & Schunn, 2009; Silk, Schunn, & Strand-Cary, 2009). This white paper provides a brief summary of principles that appear to guide successful experiences for students.


Building A Framework For Engineering Design Experiences In Stem: A Synthesis, Cameron D. Denson 2011 Utah State University

Building A Framework For Engineering Design Experiences In Stem: A Synthesis, Cameron D. Denson

Publications

Since the inception of the National Center for Engineering and Technology Education in 2004, educators and researchers have struggled to identify the necessary components of a “good” engineering design challenge for high school students. In reading and analyzing the position papers on engineering design many themes emerged that may begin to form a narrative for engineering design in a high school setting. Before educators can provide a framework for engineering design in STEM courses, four questions need to be answered: (a) To what degree should engineering design challenges be open-ended or well-structured? (b) What are the relationships between engineering design ...


Stiffness Analysis Of The Tethered Coulomb Structure Concept And Application, Stephen Panosian 2011 University of Colorado at Boulder

Stiffness Analysis Of The Tethered Coulomb Structure Concept And Application, Stephen Panosian

Aerospace Engineering Sciences Graduate Theses & Dissertations

This thesis investigates the Tethered Coulomb Structure (TCS) concept and its operating regime for creating large space structures and for providing satellite situational awareness. A TCS consists of a three-dimensional tethered spacecraft formation that uses electrostatic forces to repel the spacecraft and inflate the formation to a semi-rigid structure. The influential force modeling and equations of motion are given. Numerical simulations of a two-node TCS show that TCS systems have the greatest translational and rotational stiffness when the nodes have high voltage, low separation distance and low mass. Single tether two node TCS at 30 kV with 5 m separation ...


Sea Level Hazards: Altimetric Monitoring Of Tsunamis And Sea Level Rise, Benjamin D. Hamlington 2011 University of Colorado at Boulder

Sea Level Hazards: Altimetric Monitoring Of Tsunamis And Sea Level Rise, Benjamin D. Hamlington

Aerospace Engineering Sciences Graduate Theses & Dissertations

Whether on the short timescale of an impending tsunami or the much longer timescale of climate change-driven sea level rise, the threat stemming from rising and inundating ocean waters is a great concern to coastal populations. Timely and accurate observations of potentially dangerous changes in sea level are vital in determining the precautionary steps that need to be taken in order to protect coastal communities. While instruments from the past have provided in situ measurements of sea level at specific locations across the globe, satellites can be used to provide improved spatial and temporal sampling of the ocean in addition ...


Adaptive Formation Flying Maneuvers For Multiple Relative Orbits, Marc Saunders 2011 University of Colorado at Boulder

Adaptive Formation Flying Maneuvers For Multiple Relative Orbits, Marc Saunders

Aerospace Engineering Sciences Graduate Theses & Dissertations

In order to extend and preserve the mission of an earth orbiting satellite it is imperative that the on board maneuvers do not waste propulsion but maneuver the spacecraft optimally. The challenge for ground stations is to plan maneuvers for spacecraft that will achieve a desired orbit while minimizing fuel costs. Increasing this challenge is the addition of specific keep-out zones (constraints on the spacecraft). For example, a low-earth orbiter (LEO) may need to maintain a specific orbit plane for a sun-synchronous imaging mission but it now has to contend with opposing debris. Computing a maneuver to avoid the debris ...


Optimal Control Applications In Space Situational Awareness, Marcus J. Holzinger 2011 University of Colorado at Boulder

Optimal Control Applications In Space Situational Awareness, Marcus J. Holzinger

Aerospace Engineering Sciences Graduate Theses & Dissertations

There are currently more than 19,000 trackable objects in Earth orbit, 1,300 of which are active. With so many objects populating the space object catalog and new objects being added at an ever increasing rate, ensuring continued access to space is quickly becoming a cornerstone of national security policies. Space Situational Awareness (SSA) supports space operations, space flight safety, implementing international treaties and agreements, protecting of space capabilities, and protecting of national interests. With respect to objects in orbit, this entails determining their location, orientation, size, shape, status, purpose, current tasking, and future tasking. For active spacecraft capable ...


Response Of The Ionosphere-Plasmasphere System To Periodic Forcing, Nicholas M. Pedatella 2011 University of Colorado, Boulder

Response Of The Ionosphere-Plasmasphere System To Periodic Forcing, Nicholas M. Pedatella

Aerospace Engineering Sciences Graduate Theses & Dissertations

The role of different mechanisms for generating periodic variability in the ionosphere and plasmasphere is studied in this dissertation. The impact of vertically propagating waves of lower atmospheric origin on introducing periodic spatial and temporal variability in the ionosphere and plasmasphere is first investigated. This is comprised of several different aspects. Initial focus is on the seasonal, local time, and altitude dependence of longitude variations due to nonmigrating tides in the F-region and topside ionosphere/plasmasphere using a combination of observations and numerical models. This is facilitated by the development of a new method for mitigating the effect of multipath ...


Visual Spacecraft Relative Motion Control Using Higher Order Geometric Moments, Samantha C. Krening 2011 University of Colorado at Boulder

Visual Spacecraft Relative Motion Control Using Higher Order Geometric Moments, Samantha C. Krening

Aerospace Engineering Sciences Graduate Theses & Dissertations

This thesis studies passive visual relative control for satellites. The three main problems studied are how to keep the camera pointing at the center of the target, how to move the satellite so the camera can look at the target from a perpendicular orientation or maintain a fixed orientation, and how to maintain a nominal distance from the target. Visual target tracking within the image uses a statistical pressure snake algorithm, which tracks the outer contour of a target and allows geometric moments to be calculated. The attitude control is based off of tracking the center of the visual target ...


Analysis Of A Lidar System At The Harvest Platform For Use In Sea-Water Level Measurement And Satellite Altimeter Calibration, Scott Allen Washburn 2011 University of Colorado at Boulder

Analysis Of A Lidar System At The Harvest Platform For Use In Sea-Water Level Measurement And Satellite Altimeter Calibration, Scott Allen Washburn

Aerospace Engineering Sciences Graduate Theses & Dissertations

In July 2007, a new Light Detection And Ranging (LIDAR)-based water-level measurement system was installed at the Harvest platform with the goals of assessing potential drifts in the primary National Oceanic and Atmospheric Administration (NOAA) water level (bubbler) system, and of providing insight on other environmental conditions which may affect the bubbler accuracy. Additionally, the LIDAR provides an independent measure of significant wave height (SWH), which has traditionally been derived from nearby buoys. The open ocean environment of the Harvest Platform has presented significant challenges. Despite these difficult operating conditions, the LIDAR system has shown promise in being able ...


Integrative Remote Sensing Applications To Understanding Noctilucent Clouds And The Greenland Ice Sheet, Jason David Reimuller 2011 University of Colorado at Boulder

Integrative Remote Sensing Applications To Understanding Noctilucent Clouds And The Greenland Ice Sheet, Jason David Reimuller

Aerospace Engineering Sciences Graduate Theses & Dissertations

Integrative remote sensing methods are effective in the study of large heterogeneous phenomena that contribute towards our understanding of global climatological trends. This study focuses upon two climatological subjects of integrative remote sensing techniques: glaciers and noctilucent clouds. Glaciers are considered among the most sensitive observable effects of climate change, whereas noctilucent clouds provide a means to observe the trends of a changing atmospheric composition. Through synchronized aircraft and spacecraft observations, this study verified for the first time that synchronous imagery of noctilucent cloud structures from airborne and spaceborne platforms could be obtained as similar band structures were identified, along ...


Orbit Estimation Of Geosynchronous Objects Via Ground-Based And Space-Based Optical Tracking, Jill Tombasco 2011 University of Colorado at Boulder

Orbit Estimation Of Geosynchronous Objects Via Ground-Based And Space-Based Optical Tracking, Jill Tombasco

Aerospace Engineering Sciences Graduate Theses & Dissertations

Angles-only orbit estimation of geosynchronous objects is a unique challenge due to the dense population of clustered geosynchronous objects, the singularities of and perturbations to geosynchronous motion, and the error inherent to experimental observations of geosynchronous objects. Passive optical tracking of geosynchronous space objects has traditionally been performed by ground-based sensors, and the capability has advanced significantly through the introduction of space-based angles-only tracking. This research addresses three key facets of geosynchronous orbit estimation accuracy: improvement to the accuracy via appropriate coordinate modeling, empirical characterization of achievable ground-based angles-only estimation accuracy, and analytic modeling of the space-based angles-only estimated uncertainty ...


Modeling Earth's Outer Radiation Belt Electron Dynamics --- Radial Diffusion, Heating, And Loss, Weichao Tu 2011 University of Colorado at Boulder

Modeling Earth's Outer Radiation Belt Electron Dynamics --- Radial Diffusion, Heating, And Loss, Weichao Tu

Aerospace Engineering Sciences Graduate Theses & Dissertations

Earth's outer radiation belt is a relativistic electron environment that is hazardous to space systems. It is characterized by large variations in the electron flux, which are controlled by the competition between source, transport, and loss processes. One of the central questions in outer radiation belt research is to resolve the relative contribution of radial diffusion, wave heating, and loss to the enhancement and decay of the radiation belt electrons. This thesis studies them together and separately. Firstly, we develop an empirical Fokker-Planck model that includes radial diffusion, an internal source, and finite electron lifetimes parameterized as functions of ...


Semi-Autonomous Small Unmanned Aircraft Systems For Sampling Tornadic Supercell Thunderstorms, Jack Steward Elston 2011 University of Colorado at Boulder

Semi-Autonomous Small Unmanned Aircraft Systems For Sampling Tornadic Supercell Thunderstorms, Jack Steward Elston

Aerospace Engineering Sciences Graduate Theses & Dissertations

This work describes the development of a network-centric unmanned aircraft system (UAS) for in situ sampling of supercell thunderstorms. UAS have been identified as a well-suited platform for meteorological observations given their portability, endurance, and ability to mitigate atmospheric disturbances. They represent a unique tool for performing targeted sampling in regions of a supercell thunderstorm previously unreachable through other methods.

Doppler radar can provide unique measurements of the wind field in and around supercell thunderstorms. In order to exploit this capability, a planner was developed that can optimize ingress trajectories for severe storm penetration. The resulting trajectories were examined to ...


Estimating The Short Term Variability Of The Migrating Diurnal Tide Through Satellite Observations, Vu Anh Nguyen 2011 University of Colorado at Boulder

Estimating The Short Term Variability Of The Migrating Diurnal Tide Through Satellite Observations, Vu Anh Nguyen

Aerospace Engineering Sciences Graduate Theses & Dissertations

A method to explicitly estimate the short term variability of the migrating diurnal tide on a global scale is presented and analyzed. The method employs a least squares approach on temperature data from two satellite instruments (EOS Aura-MLS and TIMED-SABER) to estimate the daily zonal mean, migrating diurnal amplitude and migrating diurnal phase on a daily basis. The main objective of the study is to analyze the feasibility and scientific validity of this method. Biases between the instruments, revealed through a comparative analysis, are removed to reduce potential error. Effects of other tides and waves are reduced by zonal averaging ...


Dynamic Gas-Surface Interaction Modeling For Satellite Aerodynamic Computations, Marcin Dominik Pilinksi 2011 University of Colorado at Boulder

Dynamic Gas-Surface Interaction Modeling For Satellite Aerodynamic Computations, Marcin Dominik Pilinksi

Aerospace Engineering Sciences Graduate Theses & Dissertations

Drag coefficients are a large source of uncertainty when predicting the aerodynamic forces on orbiting satellites. Accordingly, the focus of this research is to improve the fidelity of drag modeling by investigating the nature of gas-surface interactions in low earth orbit. The author has investigated to what extent oxygen adsorption can influence the parameters of drag coefficient models, most notably the energy accommodation coefficient. To accomplish this, several analysis techniques are applied. Fitted drag coefficients for 68 objects were provided by Air Force Space Command Drag Analysis Office and are analyzed using analytical and numerical aerodynamic models. Gas-surface parameters are ...


One-Dimensional Spacecraft Formation Flight Testbed For Terrestrial Charged Relative Motion Experiments, Carl Seubert 2011 University of Colorado at Boulder

One-Dimensional Spacecraft Formation Flight Testbed For Terrestrial Charged Relative Motion Experiments, Carl Seubert

Aerospace Engineering Sciences Graduate Theses & Dissertations

Spacecraft operating in a desired formation offers an abundance of attractive mission capabilities. One proposed method of controlling a close formation of spacecraft is with Coulomb (electrostatic) forces. The Coulomb formation flight idea utilizes charge emission to drive the spacecraft to kilovolt-level potentials and generate adjustable, micronewton- to millinewton-level Coulomb forces for relative position control. In order to advance the prospects of the Coulomb formation flight concept, this dissertation presents the design and implementation of a unique one-dimensional testbed. The disturbances of the testbed are identified and reduced below 1 mN. This noise level offers a near-frictionless platform that is ...


Atmospheric Coupling Through Gravity Waves During Stratospheric Sudden Warmings: Gravity Wave Variations, Generation Mechanisms, And Impacts, Chihoko Yamashita 2011 University of Colorado at Boulder

Atmospheric Coupling Through Gravity Waves During Stratospheric Sudden Warmings: Gravity Wave Variations, Generation Mechanisms, And Impacts, Chihoko Yamashita

Aerospace Engineering Sciences Graduate Theses & Dissertations

Full understanding of gravity wave influences on the middle and upper atmosphere remains an unresolved research topic. The goals of this work are two-fold. First, gravity wave sources and propagation characteristics are explored using assimilated meteorological analyses from the European Centre for Medium-Range Weather Forecasting (ECMWF) during the 2009 stratospheric sudden warming (SSW). Second, gravity wave impacts on polar temperatures in the middle and upper atmosphere are examined by modulating the gravity wave parameterization scheme in the Thermosphere-Ionosphere-Mesosphere-Electrodynamics General Circulation Model (TIME-GCM). Gravity waves that are resolved in ECMWFT799 are validated with satellite and lidar observations. ECMWF gravity wave potential ...


Langevin Dynamics For The Transport Of Flexible Biological Macromolecules In Confined Geometries, Michael H. Peters 2011 Virginia Commonwealth University

Langevin Dynamics For The Transport Of Flexible Biological Macromolecules In Confined Geometries, Michael H. Peters

Chemical and Life Science Engineering Publications

The transport of flexible biological macromolecules in confined geometries is found in a variety of important biophysical systems including biomolecular movements through pores in cell walls, vesicle walls, and synthetic nanopores for sequencing methods. In this study, we extend our previous analysis of the Fokker–Planck and Langevin dynamics for describing the coupled translational and rotational motions of single structuredmacromolecules near structured external surfaces or walls [M. H. Peters, J. Chem. Phys. 110, 528 (1999); 112, 5488 (2000)] to the problem of many interacting macromolecules in the presence of structured external surfaces representing the confining geometry. Overall macromolecular flexibility is ...


A Model To Integrate Sustainability Into The User-Centered Design Process, Adrienne Shevonne Brown 2011 University of Central Florida

A Model To Integrate Sustainability Into The User-Centered Design Process, Adrienne Shevonne Brown

Electronic Theses and Dissertations

With concerns for the environment becoming more prevalent in business and the government, it is increasingly important to re-evaluate and update processes to include sustainability considerations early in the design process. In response to this charge, this research effort was designed to integrate sustainability factors into the usercentered design process. The results of this research highlight the benefits of sustainability requirement planning, as well as those derived from integrating sustainability into the current user-centered design model


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