Investigation of a liquid-fed water resistojet plume

Measurements of mass flux and flow angle were taken throughout the forward flow region of the exhaust of a liquid-fed water resistojet using a quartz crystal microbalance (QCM). The resistojet operated at a mass flow rate of 0.1 g/s with a power input of 330 Watts. Measured values were compared to theoretical predictions obtained by employing a source flow approximation. Excellent agreement between predicted and measured mass flux values was attained; however, this agreement was highly dependent on knowledge of nozzle flow conditions. Measurements of the temperature at which the exhaust condensed on the QCM were obtained as a function of incident mass flux

The effect of nonlinearities on the dynamic response of a large shuttle payload

The STS Centaur was designed to be a high energy upper stage for use with the Space Shuttle. Two versions were designed under development when the program was cancelled. The first version, designated G-prime, was for planetary missions. The second version, designated G, was to place spacecraft in geosynchronous orbit. As a part of the STS Centaur finite-element model verification effort, test articles of both versions were subjected to a series of static tests. In addition the Centaur G-prime test article was subjected to a series of dynamic tests including a modal survey. Both the static and dynamic tests showed that nonlinearities existed in the Centaur and its support system. The support system included flight-like latches. The nonlinearities were particularly apparent in tests that loaded the forward support structure of the Centaur. These test results were used to aid in the development of two improved finite-element models. The first was a linear model, while the second contained nonlinear elements at the boundaries. Results from both models were compared with the transient response obtained from a step-relaxation or twang test. The linear model was able to accurately match the low frequency response found in the test data. However, only the nonlinear model was able to match higher frequency response that was present in some of the test data. In addition the nonlinear model was able to predict other nonlinear behavior such as the dynamic jump that occurs in systems with nonlinear stiffness

The Greatest Show On Earth

Nearly everyone has visited the circus at least once in his or her lifetime. The bustle of activity, bright colors and fantastic costumes, and amazing performances of people and animals make the circus the greatest show on earth. Most people take the circus at face value: they enjoy it and go home entertained. There are others in our society who question the very existence of the circus, and in particular, the use of animals for mere amusement. With accusations of animal cruelty flying about regularly, one wonders what it is really like behind-the-scenes at the big top

Causerie

Greetings from the office of the ISU Veterinarian! As I sit and reflect on my time as editor of this unique publication, I am struck by how fast time seems to have gone since I took on this task a volume ago. At that time, I felt certain I was up to the job if only I could figure out exactly what I was supposed to do when! Three issues later, I have a clearer idea of what it takes to make this journal a reality, and perhaps I would be less apt to agree to the job had I known then what I know now

VMAA at ISU and Cedarleaf Family Trust Assist ISU Veterinarian

The staff of the ISU Veterinarian would like to extend our sincere thanks to both the Veterinary Medical Alumni Association at Iowa State University and the E. T. Cedarleaf Family Trust for providing us with funding for the purchase of a new computer system for the publication of this journal. The staff members have been making do with an old Macintosh computer for several years, and it has been increasingly apparent that this system would no longer be adequate for publishing the journal. With the generous contributions of these two benefactors, the staff has been able to purchase a Macintosh PowerPC and laser printer

Evaluating a New Approach for Improving Care in an Accident and Emergency Department: The New Care Project

This report evaluates a partnership initiative between primary and secondary care providers that is intended to improve Accident and Emergency (A&E) services at Northwick Park, one of two large acute hospitals within the North West London Hospitals NHS Trust. It considers how major strides were made during 2002/2003 towards improving A&E services to patients, and how it acted as the site for a major experiment, involving an integrated ëout-of-hoursí primary care and A&E service. Known as the NU-Care project (Northwick Urgent Care), the aim was to introduce new skills into the Department, and to improve links with other existing providers, such as primary care and NHS Direct, and thereby improve the overall patient experience