Impact shear and static flexure tests were performed on pallet stringers notched with six different fillet radii. These notches were cut with a band-saw or a stringer-notcher. Attempts were made to reduce the incidence of stringer fracture between the notches (a) by nail-reinforcing the stringers adjacent to the inner notch ends and (b) by retarding longitudinal moisture movement through the notch ends by notch coating. The leading-edge design of the paIlet was studied by determining its impact resistance if fabricated with leadboards and stringers of different species and specific gravities. The impact shear resistance and the flexural strength of notched pallet stringers increased with increasing notch fillet radii. The optimum fillet radius was one inch. No performance difference was found between the band-sawn and machine-shaped notches. Nail-reinforcing slightly increased the immediate flexural strength at initial failure of green stringers; did not increase the delayed flexural strength of seasoned stringers; and increased their immediate and delayed ultimate flexural strength. Notch-coating progressively increased the delayed ultimate flexural strength during the seasoning period. Leadboard and stringer specific gravity effected the leading-edge impact resistance of wooden pallets. It increased more rapidly if the leadboard specific gravity was increased. An increase in the stringer specific gravity did not necessarily increase the leading-edge impact resistance. Optimum leading-edge impact resistance should be attained by using high-density lumber assembled with a supplementary nai I driven through the leadboard into the center stringer, provided lumber splitting is avoided. / Master of Architecture

In performing wind tunnel model tests of a two-dimensional nature, a grid constructed of 3.6 x 0.75 inch boards on 18 inch centers was used at the entrance of the tunnel. Important properties of the turbulent flow behind the uniform coarse grid were determined. The flow was found to be quite uniform at a distance of 38 bar widths downstream of the grid. Use of this flow to simulate atmospheric turbulent flows for testing sectional models of suspension bridges is discussed. The power spectra of the turbulence was found to agree quite well with the von Karman spectrum equation for atmospheric turbulence. The integral length scales were found to increase with increasing distance downstream of the grid. Integral length scales of the longitudinal turbulence component were found to increase in size as the mean velocity was increased. Measurements indicate that grid turbulence seems to model the atmospheric turbulence quite well for studies of suspension bridges and other elevated structures. Meaningful quantitative results may be obtained if geometric modeling of the integral length scales of the atmospheric turbulence is of minor importance for proper model response. / Master of Science / incomplete_metadata

In this thesis I explore the following question: When a government agency is charged with implementing policies formulated in the light of scientific principles, why do the justifications for implementation differ from justifications for the legislation? The predator reintroduction being carried out under the Northern Rocky Mountain Wolf Recovery Plan, now 19 years old, has recently catalyzed a national controversy about the value of wildlife. My goal is to examine the reasons why the ecological values that infuse government policy play little part in governmental justifications for policy implementation. / Master of Science

The Virginia Department of Education suggested that its school divisions adopt an Evaluation by Objectives (EBO) teacher evaluation system as a means for its school divisions to satisfy the personnel evaluation section of the Standards of Quality mandate. This study surveyed Virginia's principals as to their use of and perceptions of the efficacy of the suggested EBO model. In addition, the study examined specific personal (age, years of administrative experience, membership in a teacher organization) variables and institutional (number of teachers in the school, number of teachers evaluated, EBO training, hours of EBO training) variables as possible predictors of the dependent variable, principal's perceived effectiveness of the suggested EBO procedures. The survey results indicated that 95.5 percent of the principals used or modified the procedures. The majority of these principals (86.8 percent) perceived the procedures to be effective, in improving teacher performance. Multiple regression analysis (MRA) was used to test the predictive strength of the independent variables identified in this study. The variables, although significant at the .01 level, were not meaningful as predictors of principals' perceived effectiveness of EBO. The adjusted R² coefficient of determination was only 5.9 percent. / Ed. D.

Christoforos N. Hadjicostis. / Also issued as Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999. / Includes bibliographical references (p. 189-196). / Sponsored through a contract with Sanders, A Lockheed Martin Company.

John A. McKenzie. / "June 1999." / Includes bibliographical references (leaves [1]-[2]).

Shawn M. Verbout. / "June 1999." / Includes bibliographical references (p. [225]-240). / Sponsored by the U.S. Air Force. F49620-96-1-0072 Supported by the U.S. Army Research Laboratory under Cooperative Agreement, DAAL01-96-2-001

Warren M. Lam and Gregory W. Wornell. / "October 1998"--Cover. / Includes bibliographical references (p. 33-34). / Supported by DARPA monitored by ONR. N00014-93-1-0686, N00014-96-1-0930 Supported by AFOSR. F49620-1-0072

hosted [and edited] by J. Kennedy Salisbury and Mandayam A. Srinivasan. / "December, 1998." / Includes bibliographical references. / Sponsored by SensAble Technologies, Inc., Cambridge, MA.

Haralabos Christos Papadopoulos. / Includes bibliographical references (p. 163-165). / Also issued as a Ph.D. thesis, Dept. of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 1998. / Sponsored by the Advanced Research Projects Agency monitored by the Office of Naval Research. N00014-93-1-0686 Sponsored by the Air Force Office of Scientific Research. F49620-96-1-0072 Sponsored in part by the U.S. Army Research Laboratory under the Federated Laboratory Program. Cooperative Agreement No. DAAL01-96-2-0002