Long-Term Quantitative Study of Wind-Tunnel Balance Calibrations Across Multiple Calibration Systems

Internal strain-gauge balances are multi-dimensional force transducers widely employed in wind tunnels to obtain accurate aerodynamic force and moment data on an aircraft model. Balances are calibrated periodically to assure measurement accuracy. The calibration provides a mathematical model relating the forces applied to the balance and the output signal from the balance. Currently, there are multiple types of internal strain-gauge balances used in wind-tunnel testing as well as multiple methods by which balances are calibrated. Because of the differences in the hardware and methodologies used to calibrate a wind-tunnel balance, it is hard to quantify the differences seen between the calibration results. The purpose of this study is to understand how the calibration of a balance is affected by the calibration system. Additionally, the study examines how the performance of a balance changes over time from a calibration perspective. These differences are quantified across different types of balances and different types of calibration systems. The long-term study employs multiple rigorous statistical methods as well as statistical process control techniques to provide insight into the stability of a process over time

Profile Synthesis of Prismatic-Prismatic Variable Joints for Use In Reconfigurable Mechanisms

Reconfigurable mechanisms provide increased flexibility in machine design and can be used in a variety of applications. Variable joints in reconfigurable mechanisms allow for machine designs that better optimize space and resources. This thesis uses a configuration space analysis to determine the motion profiles of Prismatic-Prismatic higher variable joints. Prismatic-Prismatic variable joints have never been analyzed or synthesized. In addition, no variable joints of any type have been considered with two-dimensional contact points. Variable joints enable the creation of Type II Mechanisms with Variable Topology, mechanisms whose topology changes due to changes in joint geometry. The goal of this synthesis is to synthesize Prismatic-Prismatic variable joints with one and two-dimensional contacts, outline their designs, and determine the design restrictions for each variation

CENTER OF PRESSURE EXCURSION DURING A SINGLE LEG STANDING TEST IN AMBULATORY CHILDREN WITH CEREBRAL PALSY

INTRODUCTION: Cerebral Palsy (CP) is the most common disabling motor disorder found during childhood, occurring in 2.1-3.2 of every 1,000 births. Motor functionality of children with CP is commonly compromised and is classified with a gross motor function classification score (GMFCS) and with the gross motor function measure (GMFM). Balance ability has typically been assessed using single leg stance test (SLST) time but more recently, center of pressure excursion (COPE) has shown to be a more valid measurement in populations with altered motor abilities. However, COPE has not been used to test balance in the CP population, yet. This study aimed to determine if relationships were present between COPE measurements, functionality measurement scores (GMCS and GMFM) and reported fall frequency. It was hypothesized that i) larger COPE measurements would be associated with a higher GMFCS level and lower GMFM score, and that ii) COPE measurements would be significantly higher in children with a high reported incidence of fall frequency. METHODS: Gross functionality was measured using a GMFM score and GMFCS level. Balance ability was assessed using COPE measurements on a force plate and SLST time. Fall frequency was determined by a short questionnaire. A Pearson correlation analyzed COPE measurements vs. mean GMFM score. A one-way ANOVA was used to compare COPE measures between GMFMCS levels, with a Bonferroni post-hoc test. Lastly, an independent sample t-test analyzed differences in COPE measurements and SLST time between fall frequency groups. RESULTS: Significantly larger COPE velocities were demonstrated in children who reported a greater number of falls in the past month and were considered high risk for falling (p = 0.02). No relationships were demonstrated between COPE measurements and GMFM score. GMFCS level III participants demonstrated statistically significant lower COPE velocity compared to GMFCS level II participants (p = 0.05). There were no significant differences in SLST between high and low risk fall groups (p = 0.07). DISCUSSION: Children with higher reported fall frequencies demonstrated a 60% increase in COPE velocity, compared to those with little to no falls. Clinical GMFM scores did not demonstrate significant correlations to COPE measurements and may not be an appropriate identifier for falling in children diagnosed with CP. This is the first trial to evaluate COPE measurements and reported fall frequencies in children diagnosed with CP. The use of a force plate to determine COPE velocity during a SLST is useful in identifying children with CP who may be at an elevated risk for experiencing a fall. COPE velocity was able to provide intricate quantitative data regarding fall risk that could not be obtained during a normal SLST

The Grizzly, September 3, 2009

Summer Fellows: Students Skip the Beach and Hit the Books • UCTV Returns: Bringing Back the News • Theft on Campus: Tips to Keep You Safe • Four Big Changes Hit Campus This Summer • Interning with Joan Jett: Taking Advantage of the UC Opportunity • UC Community Service Center: Encouraging Benevolence on Campus • Bridging the Gap Between 2010 and 2013 • Dan Mullen \u2794 Named Mississippi State Head Coach • John Noonan: Full Court Press to Europe, Summer 2009https://digitalcommons.ursinus.edu/grizzlynews/1789/thumbnail.jp

Ultrathin Stable Ohmic Contacts for High-Temperature Operation of β\beta-Ga2_2O3_3 Devices

Beta gallium oxide ($\beta$-Ga$_2$O$_3$) shows significant promise in the high-temperature, high-power, and sensing electronics applications. However, long-term stable metallization layers for Ohmic contacts at high temperature present unique thermodynamic challenges. The current most common Ohmic contact design based on 20 nm of Ti has been repeatedly demonstrated to fail at even moderately elevated temperatures (300-400$^{\circ}$C) due to a combination of non-stoichiometric Ti/Ga$_2$O$_3$ interfacial reactions and kinetically favored Ti diffusion processes. Here we demonstrate stable Ohmic contacts for Ga$_2$O$_3$ devices operating up to 500-600$^{\circ}$C using ultrathin Ti layers with a self-limiting interfacial reaction. The ultrathin Ti layer in the 5nm Ti / 100nm Au contact stack is designed to fully oxidize while forming an Ohmic contact, thereby limiting both thermodynamic and kinetic instability. This novel contact design strategy results in an epitaxial conductive anatase titanium oxide interface layer that enables low-resistance Ohmic contacts that are stable both under long-term continuous operation (>500 hours) at 600$^{\circ}$C in vacuum ($\leq$ 10$^{-4}$ Torr), as well as after repeated thermal cycling (15 times) between room temperature and 550$^{\circ}$C in flowing N$_2$. This stable Ohmic contact design will accelerate the development of high-temperature devices by enabling research focus to shift towards rectifying contacts and other interfacial layers.Comment: 25 Pages, 7 Figure

The Grizzly, February 14, 2008

Writer\u27s Strike May See a Silver Lining • Ellison Unveils Art Exhibit in Berman • Relief for Students? College Endowments Skyrocket • Ursinus Designs New Certificate for International Studies • Is Everybody Really Doing It? The Indictment of the Greek Community at Ursinus College Surprises Many • Ursinus Community Shares its Dirty Little Secrets • Focus the Nation and Environmentalism: No Longer Just for Hippies • UC Study Abroad Helpful Hints • Opinions: Lessons from Super Tuesday; Does The Times Need Bill Kristol?; Lessons from the Hormuz Strait • Ursinus Wrestlers Clinch Dual Meet • UC Indoor Track Teams Make Big Moves, Heat Up Competitionhttps://digitalcommons.ursinus.edu/grizzlynews/1755/thumbnail.jp

The Grizzly, April 28, 2011

New U Hosts Spring Into Wellness Month • College Campuses are a Hotbed for Theft • Take a Little Break with Activities from Around Collegeville • Relay for Life Benefits American Cancer Society • Active Minds Hosts Art Festival • Senior Reflection: The Past was Worth the Future • Students Uncover Papers from the Third Reich • Internship Spotlight: Sierra Guerin • Opinions: The Magic is in the Turning of the Page; Books and Electronic Books can Coexist; A New (Satirical) Take on Racial (In)equality at Ursinus • Looking Past Senioritis: Importance of Giving Back to UC • Senior Spotlight: Runner Jeremy Garavelhttps://digitalcommons.ursinus.edu/grizzlynews/1836/thumbnail.jp

The Grizzly, May 6, 2010

Students in Free Enterprise Wins Regional Competition • Ursinus Celebrates Student Artwork with Annual Exhibit • Students Volunteer with UCARE\u27s Community Week • Gala to Benefit Education in Haiti • Ursinus Bike Share Goes National • Seniors Reflect on UC Memories • Senior Spotlight: UC Softball\u27s Lauren Davis-Macedonia; Track and Field\u27s Travis Youngshttps://digitalcommons.ursinus.edu/grizzlynews/1814/thumbnail.jp

The Grizzly, April 24, 2008

Ursinus College Dance Company Kicks Off Tonight! • CoSA at UC! • Charity Events in the Classroom • Red Sky in Morning • Another Collegeville Restaurant Review: BonJung • Ursinus Graduate Awarded Watson Fellowship • Achievement Gap: Close to Home • Opinions: Bush / Clinton Dynasty? • Weekend Success and Dubb Appreciation Week • UC Softball Flying High After Wins Against Gettysburg • Great Success Strikes Men\u27s Laxhttps://digitalcommons.ursinus.edu/grizzlynews/1763/thumbnail.jp

The Iowa Homemaker vol.26, no.2

Alma Mater, J. C. Harris, page 2 Travel With Poise, Mary Ann Hakes, page 3 Report From Athens, Joan Kelleher, page 4 Blanche Pederson Interviews an Aussie Bride, Blanche Pederson, page 5 Coeds are Veterans, Too, Mary Margaret Ryan, page 6 Future Home Economics Classroom, Helen Hochriem, page 7 Vicky Grins at the Sun, Breta Soldat, page 9 What’s New in Home Economics, Marjorie Clampitt, page 10 Wardrobe Worries? Here’s What We Wear, Textiles and Clothing Club, page 12 “I Have a Dozen Bosses”, Genevieve Callahan, page 14 Albino Rats Get in on the Ground Floor, Margaret Waterland, page 17 Alums Prove Chemistry can Pay, June Welch, page 18 Education Begins Egyptian Modernizing, Lois Bronson, page 19 Across Alumnae Desks, Mary Neff, page 21 Keeping Up With Today, Joyce Edgar, page 22 How Does Your Garden Grow?, Irene Meyer, page 23 Alums in the News, Goldie Rouse, page 2