High resolution measurement of FGM thin films using picosecond ultrasonics

AbstractFunctionally Graded Materials (FGMs) are materials with elastic properties λ, μ and density ρ depending on spatial coordinates. When between two homogeneous materials the transition layer thickness is of the same order of magnitude as the mechanical wave length, the wave scattering behavior at the interface becomes frequency dependent. The effect is of growing importance for micro- and nanostructures since the relative size of the interface layers is generally larger than in macroscopic structures. In this work a linear material grading is achieved with physical vapor deposition by magnetron sputtering. The used materials are aluminum (Al) and tantalum (Ta) due to their strong variation in acoustic impedance (bulk force reflection coefficient 0.6) and their good intermixing properties. In the sample investigated here the material transition layer thickness amounts to 60nm. With Rutherford Backscattering Spectroscopy (RBS) measurements and electron microscopy (SEM/TEM) the material properties of the sample are characterized. Mechanical waves in the specimen are excited and detected using a pump probe laser acoustic setup. The frequency dependent wave propagation in FGM is demonstrated by investigating the spectral response in theory and experiments. The entire experimental setup is modeled using a finite difference algorithm for better interpretation of the measurements. The frequency dependent wave propagation in FGM is analyzed to characterize the interface and finds applications in high frequency filters, semiconductor manufacturing or thermal barrier layers

In the Eye of the Beholder? Motivated Reasoning in Disputed Elections

This study uses an experimental design to simulate the ballot counting process during a hand-recount after a disputed election. Applying psychological theories of motivated reasoning to the political process, we find that ballot counters’ party identification conditionally influences their ballot counting decisions. Party identification’s effect on motivated reasoning is greater when ballot counters are given ambiguous, versus specific, instructions for determining voter intent. This study’s findings have major implications for ballot counting procedures throughout the United States and for the use of motivated reasoning in the political science literature

Exercise Improves Vascular Dilator Reactivity in Chronically Stressed Rats with Pre-existing Metabolic Syndrome

Please refer to the pdf version of the abstract located adjacent to the title

Exercise as a Treatment for Peripheral Vascular Dysfunction Caused by Metabolic Syndrome and Depression

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Prosthetic Knee

Amputations, specifically lower limb amputations, are common in Sub Saharan Africa and across the broader global community largely due to infection and disease. Our project, The Prosthetic Knee Team, partners with the orthopedic workshop at the CURE International Hospital in Kijabe, Kenya to create a prosthetic knee design for a specific type of amputation known as a Knee Disarticulation (also called through-knee). Currently, the orthopedic workshop is only able to provide one very expensive prosthetic knee option for these patients, and they often elect to undergo a second surgery, a trans-femoral amputation, because the cost of the second surgery and trans-femoral prosthesis combined is less than the currently available through-knee prosthetic. The goal of our project is to provide the orthopedic workshop with a manufacturable prosthetic knee design that provides through-knee amputees with a cheaper prosthetic option and removes the need to have a second amputation above the knee. Throughout the past two semesters, our focus was on organizing collected data, researching knee-disarticulations, and communicating with our client to more fully understand the scope of our project. After determining that moving forward our project will be manufacturing the prosthetic knees at Messiah College’s machine shop and shipping them to CURE Kenya to be fit on patients, we began to brainstorm potential design ideas. We are presently working on modifying and improving our chosen design to best meet all of the specifications laid out by our partner. Those specifications include minimized thigh-lengthening, low weight, maximized stability and durability, and aesthetically pleasing.https://mosaic.messiah.edu/engr2020/1017/thumbnail.jp

Training in crisis communication and volcanic eruption forecasting:Design and evaluation of an authentic role-play simulation

We present an interactive, immersive, authentic role-play simulation designed to teach tertiary geoscience students in New Zealand to forecast and mitigate a volcanic crisis. Half of the participating group (i.e., the Geoscience Team) focuses on interpreting real volcano monitoring data (e.g., seismographs, gas output etc.) while the other half of the group (i.e., the Emergency Management Team) forecasts and manages likely impacts, and communicates emergency response decisions and advice to local communities. These authentic learning experiences were aimed at enhancing upper-year undergraduate students’ transferable and geologic reasoning skills. An important goal of the simulation was specifically to improve students’ science communication through interdisciplinary team discussions, jointly prepared, and delivered media releases, and real-time, high-pressure, press conferences. By playing roles, students experienced the specific responsibilities of a professional within authentic organisational structures. A qualitative, design-based educational research study was carried out to assess the overall student experience and self-reported learning of skills. A pilot and four subsequent iterations were investigated. Results from this study indicate that students found these role-plays to be a highly challenging and engaging learning experience and reported improved skills. Data from classroom observations and interviews indicate that the students valued the authenticity and challenging nature of the role-play although personal experiences and team dynamics (within, and between the teams) varied depending on the students’ background, preparedness, and personality. During early iterations, observation and interviews from students and instructors indicate that some of the goals of the simulation were not fully achieved due to: A) lack of preparedness, B) insufficient time to respond appropriately, C) appropriateness of roles and team structure, and D) poor communication skills. Small modifications to the design of Iterations 3 and 4 showed an overall improvement in the students’ skills and goals being reached. A communication skills instrument (SPCC) was used to measure self-reported pre- and post- communication competence in the last two iterations. Results showed that this instrument recorded positive shifts in all categories of self-perceived abilities, the largest shifts seen in students who participated in press conferences. Future research will be aimed at adapting this curricula to new volcanic and earthquake scenarios

Pre-divorce problems in 3-year-olds: a prospective study in boys and girls

Objective: We examined to what extent internalizing and externalizing problems at age 3 preceded and predicted parental divorce, and if divorce and the time lapse since divorce were related to internalizing and externalizing problems at age 12. Methods: Parental ratings of internalizing and externalizing problems were collected with the Child Behavior Checklist (CBCL) in a large sample (N = 6,426) of 3-yearold children. All these children were followed through the age of 12 years, at which parents completed the CBCL again, while teachers completed the Teacher's Report Form. Children whose parents divorced between age 3 and age 12 were compared with children whose families remained intact. Results: Girls whose parents divorced between ages 3 and 12 already showed more externalizing problems at age 3 than girls whose parents stayed married. Higher levels of externalizing problems in girls at age 3 predicted later parental divorce. Parental reports indicated that 12-year-olds with divorced parents showed more internalizing and externalizing problems than children with married parents. Levels of teacher-reported problems were not different between children with married versus divorced parents. However, children whose parents divorced between ages 3 and 12 showed more teacher-rated internalizing problems at age 12 when the divorce was more recent than when the divorce was less recent. Parental ratings of both internalizing and externalizing problems at age 12 were not associated with the time lapse since divorce. Conclusion: Externalizing problems in girls precede and predict later parental divorce. Post-divorce problems in children vary by raters, and may depend on the time lapse since divorce