Thermal-capillary model for Czochralski growth of semiconductor materials

The success of efficiently calculating the temperature field, crystal radius, melt mensicus, and melt/solid interface in the Czochralski crystal growth system by full finite-element solution of the government thermal-capillary model is demonstrated. The model predicts realistic response to changes in pull rate, melt volume, and the thermal field. The experimentally observed phenomena of interface flipping, bumping, and the difficulty maintaining steady-state growth as the melt depth decreases are explained by model results. These calculations will form the basis for the first quantitative picture of Cz crystal growth. The accurate depiction of the melt meniscus is important in calculating the crystal radius and solidification interface. The sensitivity of the results to the equilibrium growth angle place doubt on less sophisticated attempts to model the process without inclusion of the meniscus. Quantitative comparison with experiments should be possible once more representation of the radiation and view factors in the thermal system and the crucible are included. Extensions of the model in these directions are underway

No more A-/a/-apple: An Examination of Kindergarten and First Grade Phonics within a Progressive Framework

Examines the approach to teaching literacy taken by back to basics and progressive educators, and the role of phonics within each type of literacy program. The necessity and application of phonics for kindergarten and first grade children is discussed, grounded in the author\u27s experience teaching in a progressive private school and a back to basics charter school. I found from research and my experience, that phonics is a necessary component for any complete literacy program. In addition, learning phonics has a stronger and more positive effect on children\u27s early reading and writing when it is taught within a developmentally appropriate, experiential, and progressive approach to literacy (Cunningham & Allington, 2003; Pinnell & Fountas, 1998; Moustafa, 1997). A brief overview of progressive research on phonics and learning to read is included, as well as phonics- and phonemic awareness-based activities grouped by ability level and target skill. These activities are intended to provide a practical example of phonics within a progressive framework. Finally, the connection is made between ensuring quality literacy education for all children and the ongoing struggle for socioeconomic justice and equity in our society

Optical-inertia space sextant for an advanced space navigation system, phase B

Optical-inertia space sextant for advanced space navigation syste

Droplet ejection and sliding on a flapping film

Citation: X. Chen, N. Doughramaji, A.R. Betz, M.M. Derby, Droplet departure and ejection on flapping films, AIP Advances, 7, 035014.Water recovery and subsequent reuse are required for human consumption as well as industrial, and agriculture applications. Moist air streams, such as cooling tower plumes and fog, represent opportunities for water harvesting. In this work, we investigate a flapping mechanism to increase droplet shedding on thin, hydrophobic films for two vibrational cases (e.g., ± 9 mm and 11 Hz; ± 2 mm and 100 Hz). Two main mechanisms removed water droplets from the flapping film: vibrational-induced coalescence/sliding and droplet ejection from the surface. Vibrations mobilized droplets on the flapping film, increasing the probability of coalescence with neighboring droplets leading to faster droplet growth. Droplet departure sizes of 1–2 mm were observed for flapping films,compared to 3–4 mm on stationary films, which solely relied on gravity for droplet removal. Additionally, flapping films exhibited lower percentage area coverage by water after a few seconds. The second removal mechanism, droplet ejection was analyzed with respect to surface wave formation and inertia. Smaller droplets (e.g., 1-mm diameter) were ejected at a higher frequency which is associated with a higher acceleration. Kinetic energy of the water was the largest contributor to energy required to flap the film, and low energy inputs (i.e., 3.3 W/m2) were possible. Additionally, self-flapping films could enable novel water collection and condensation with minimal energy input

International web survey of chiropractic students about evidence-based practice: a pilot study

<p>Abstract</p> <p>Background</p> <p>Positive attitude toward evidence-based practice (EBP) principles in healthcare education may be one of the first steps for motivating a healthcare professional student to later apply EBP principles in clinical decision-making. The objectives for this project were to pilot an international web-based survey of chiropractic students and to describe student attitudes, behaviors, and knowledge about EBP principles.</p> <p>Methods</p> <p>We used SurveyMonkey™ to develop our survey based on an existing questionnaire used to measure basic knowledge, skills and beliefs about EBP among allied healthcare professionals and CAM practitioners. We invited 26 chiropractic educational institutions teaching in English and accredited by official organizations to participate. Academic officials and registrars at participating institutions forwarded an invitation email and two reminders to students between July and September 2010. The invitation contained a link to the 38-item web-based questionnaire. Descriptive statistics were performed for analysis.</p> <p>Results</p> <p>Fourteen institutions from Australia, Canada, US, Denmark and New Zealand participated. Among an estimated 7,142 student recipients of invitation letters, 674 participated in the survey for an estimated response rate of 9.4%. Most respondents reported having access to medical/healthcare literature through the internet, but only 11% read literature every week and 21% did not read literature at all. Respondents generally agreed that the use of research evidence in chiropractic was important. Although 76% of respondents found it easy to understand research evidence and 81% had some level of confidence assessing the general worth of research articles, 71% felt they needed more training in EBP to be able to apply evidence in chiropractic care. Respondents without previous training in research methods had lower confidence in assessing published papers. While more than 60% marked the correct answer for two knowledge items, the mean number of correct answers to the five knowledge questions was 1.3 (SD 0.9).</p> <p>Conclusions</p> <p>Although it is feasible to conduct an international web survey of chiropractic students, significant stakeholder participation is important to improve response rates. Students had relatively positive attitudes toward EBP. However, participants felt they needed more training in EBP and based on the knowledge questions they may need further training about basic research concepts.</p

Extended Reality (XR) Hardware: One Size Doesn’t Fit All, Yet.

Extended Reality (XR) encompasses virtual reality (VR), augmented reality (AR), and mixed reality (MR). Virtual content continues to be incorporated into our real world as more devices become available to support it. It has been accepted into the entertainment space (games like Beat Saber and Pokémon GO), social media apps (SnapChat and TikTok filters), training, and education. Soon everyone will be able to put on a headset or pick up a phone and see virtual holograms in action. But, is XR built inclusively, for everyone? Inclusive design has been defined as, designing a diversity of ways for users to participate so that everyone has a sense of belonging” (Holmes, 2018). We evaluated the inclusivity of popular XR devices: head-mounted displays, smart glasses, and mobile devices – both the physical design and user interaction methods. Results demonstrate that the devices have room for improvement to be fully inclusive

Optical inertial space sextant for an advanced space navigation system

Dual field optical tracking system and television camera chain combined with two gyroscopes to form space navigation sextant

The speaking vocabulary of grade two

Thesis (M.A.)--Boston Universit