1,075 research outputs found
Unlawfully and riotously assembled in the City of St. Louis: The Workingmen\u27s Party\u27s Role During the Great Strike of 1877 in St. Louis
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
Learning Functions Through Vending Machines
Given the prevalence of function concepts in high school math classes, students need to
develop a deep conceptual understanding of the topic. Technology tasks have become a frequent
tool used in the high school classroom to teach functions. Technology is thought to enhance
students' understanding of functions and foster a deeper understanding. The Vending Machine
Task, through GeoGebra, provides students with various virtual vending machines to make
selections and determine if each machine is a function or not. In this study, I have explored the
effectiveness of technology centered tasks, such as the Vending Machine Task, and studied the
strategies and academic language used while completing the task. My findings will show that
the Vending Machine Task, and other technology tasks, expand students’ thinking of functions
and help build deeper conceptual understanding
The influence of hydrodynamic environment on the nucleation mechanism of a chiral crystallization
This thesis presents the results and discussions of an investigation into nucleation
mechanisms in a cooling crystallization of sodium chlorate in both a stirred tank
crystallizer (STC) and an oscillatory baffled crystallizer (OBC) under various
crystallizer configurations and operational conditions.
The key question to be addressed was why nucleation took place in an OBC
without seeds, while seeds were essential in an STC for the same chemistry and at the
same process conditions. Various hypotheses have been initiated, tested and verified in
both primary and secondary nucleation experiments, and new scientific insights and
better understanding have been achieved on the parameters that have influenced the
nucleation mechanisms and some explanations as to why seeds were not necessary in
the OBC are put forward.
For the seeded nucleation, the fluid dynamic environment and mixing mechanics
were responsible for dictating the nature of the nucleation mechanism. The unique
scraping action of the baffles against the crystallizer wall in the OBC enabled a different
enantiomorphism of the product crystals compared to the seed crystal. Removing such
a motion in the OBC provided product crystals similar to that seen in the STC. The
degree and the means of mixing near the single seed crystal also affected the crystal
handedness. For the primary nucleation experiments, it was found that the handedness
of the product crystals in the STC was strongly orientated towards a single
enantiomorph, while both enantiomorphs were formed in the OBC. The results were
suggestive of a lower free energy barrier in the OBC, in turn resulting in primary
nucleation being favoured in the OBC as opposed to rapid secondary nucleation being
dominant in the STC
MARINE CORPS OFFICER ATTITUDES TOWARD THE REPEAL OF "DON'T ASK, DON'T TELL"
"Don't Ask, Don't Tell" (DADT) prohibited gays from serving openly in the military from December 1993 to September 2011. The present study, conducted over one year after DADTs repeal, utilized a survey of attitudes toward DADT that was previously administered to Marine Corps officers at the Naval Postgraduate School (NPS) in 1999, 2004, and 2010. This survey, re-administered to NPS Marine officers in November 2012, addressed the following areas policy, cohesion, leadership, tolerance, unit effectiveness, and military readiness. A comparison of results from the four surveys shows a clear trend of increasing acceptance toward homosexuals in the military. Levels of acceptance tended to vary by Military Occupational Specialty and length of service. Additionally, many Marine officers continued to express concern about habitability and personal comfort. These and other issues were further explored with Marine officers in three focus-group sessions. Overall, study results indicated strong agreement that the current policy protects the rights of all Marines, regardless of sexual orientation. Finally, Marine officers expressed confidence that the training they received adequately prepared them to execute the repeal of DADT. The thesis includes appendices with survey trend data from 1999 to 2012 and response frequencies from a concurrent survey of Navy officers.http://archive.org/details/marinecorpsoffic1094532802Captain, United States Marine Corps;Lieutenant Commander, United States NavyApproved for public release; distribution is unlimited
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