Academic literature on the topic 'LD5655.V855 1995.S672'

This thesis presents a technique for synthesizing weighted four-bar linkages to produce a specified resisting force or torque. Historically, mechanism force synthesis has assumed that output positions must always be associated with prescribed forces. This results in the loss of design parameters. Applications which do not require a specified output position benefit from the design method presented in this thesis. This thesis presents two significant contributions to the field of kinematics. First, it contains a full development and demonstration of the use of integrated force constraints to develop position constraints for linkages. Second, it presents the development and use of inverse-mechanical-advantage sensitivity as an evaluation and design tool. The mathematical derivation of a novel synthesis technique is presented in full detail. Also presented is a complete and robust design method for force-generating linkages that has been implemented in software, tested in hardware design, and adopted by industry. The closed-form-equation-based synthesis technique developed herein provides the designer with a graphical representation of an infinite solution set to the force generation problem. Associated sensitivity, static and dynamic analyses allow the designer to quickly evaluate each solution.
Master of Science

In order to make a more attractive and efficient built environment, residential architecture must be incorporated into the fabric of the city. The most successful cities have a mixture of business and residential activities. In most cities, business flourishes in the center, while housing is pushed out to the edges. This causes the city centers to be occupied by day, but abandoned at night. A city with integrated housing becomes a community, a place where people call home. When the city becomes a backyard, it is thought of more carefully and considered to be more important. For this to take place, good urban housing must exist to accommodate the people who will make the city come to life. This urban housing must be attractive enough to make people want to stay for long periods of time and invest in their own improvements. Personalization and pride in a city allow its residents to feel safe and comfortable. When someone respects the place they live in, they respect the environment around it. In other words, good housing is the foundation for a successful community. The objective of this project was to architecturally manifest an urban residential complex that could foster pride and personal identity for the city dweller. The Cameron Street Housing site provided the perfect arena for this objective in Old Town Alexandria, Virginia. The existing surroundings called for a medium density complex that respected the historical styles and showed innovation to accommodate contemporary living. The concept of the project centered around the separation and identity of one's home, the creation of a community within a community, and the use of thresholds to provide layers of space between the public and the private. The forms and materials reflect the surrounding typology without imitating it; the living units conform to modern living without limiting the types of family structures that can inhabit them, and the site provides a sanctuary for its residents while it gives something back to the community. The Cameron Street Housing design stands as an example of what urban housing can do to improve the city around it.
Master of Architecture

Mean overwintering survival of beetles was 20.5 ± 17.2% and 21.3 ± 3.6% for two consecutive years. Leaf litter was the preferred hibernaculum followed by straw. Successful overwintering was not compatible with water saturated soil. The mean supercooling point of C. rubiginosa in summer was -5.2 ± 1.5°C and was significantly different (P<0.05) from mean supercooling points of -9.3 ± 2.1°C in fall and -8.8 ± 2.3°C in winter. Females studied individually produced an average of 61.1 ± 29.9 oöthecae/female under field temperatures for the period of May 2 through August 13. Development from egg to adult under field temperatures required an average of 27.4 ± 1.7 days when reared on Canada thistle and 28.5 ± 2.1 days on an alternate host, musk thistle. Mortality due to incomplete development totaled 52.5% for immatures reared on Canada thistle and 79.0% for immatures reared on musk thistle. Mean survival from egg to adult of beetles maintained in field cages ranged from 18.3 ± 26.7%. Mean survival from early (1st - 3rd) instar to adult averaged 22% for beetles confined in field cages and 16% for beetles not confined in cages. Ingestion of leaves treated with the herbicides glyphosate and 2,4-D had neither a positive nor negative effect on amount of feeding by C. rubiginosa adults and did not appear to affect the longevity of adult beetles or the fecundity of females.
Master of Science