Comparison of Raised and Flat-Seam Baseballs

The difference in seam-height between raised and flat-seam baseballs leads to different different drag and spin forces when the balls are thrown by a pitcher. The goal of this experiment is to measure the difference in vertical deflection of curveball pitches, caused by the different seam-heights

Tethers

A tether of sufficient strength, capable of being lengthened or shortened and having appropriate apparatuses for capturing and releasing bodies at its ends, may be useful in propulsion applications. For example, a tether could allow rendezvous between spacecraft in substantially different orbits without using propellant. A tether could also allow co-orbiting spacecraft to exchange momentum and separate. Thus, a reentering spacecraft (such as the Shuttle) could give its momentum to one remaining on orbit (such as the space station). Similarly, a tether facility could gain momentum from a high I(sub sp)/low thrust mechanism (which could be an electrodynamics tether) and transfer than momentum by means of a tether to payloads headed for many different orbits. Such a facility would, in effect, combine high I(sub sp) with high thrust, although only briefly. An electrodynamic tether could propel a satellite from its launch inclination to a higher or lower inclination. Tethers could also allow samples to be taken from bodies such as the Moon. Three types of tether operations are illustrated. The following topics are discussed: (1) tether characteristics; (2) tether propulsion methods--basics, via momentum transfer, and electrodynamic tether propulsion; and (3) their use in planetary exploration

Handbook in woodworking for special class teachers

Thesis (Ed.M.)--Boston University, 1947. This item was digitized by the Internet Archive

The Dismantling of De Jure Segregation in Louisiana, 1954-1974. (Volumes I and II).

In the two decades between 1954 and 1974, the State of Louisiana progressed from a closed, white-dominated society to an open, multi-racial society with legal safeguards in place to assure equal protection and equal opportunity for all residents regardless of race or color. Prior to 1960, the vast majority of blacks were unable to vote, serve on juries, buy homes in decent neighborhoods, use publicly-owned facilities or frequent hotels, restaurants and other public accommodations. In addition to these humiliations, they were required to utilize inadequate separate but equal public parks, playgrounds, swimming pools, schools, waiting areas and correctional facilities until the mid-1960\u27s. Most of the state\u27s segregated institutions were desegregated between 1964 and 1969. The major desegregation battle was fought in public elementary and secondary schools. As the 1960\u27s came to a close, the foundations had been laid for the creation of unitary school systems, desegregation of correctional facilities and prohibition of racial discrimination in housing and employment. With the dawn of the 1970\u27s, a more conservative mood swept the nation, but a more progressive decade began in Louisiana. Although the enigma of a dual system of higher education continued to escape resolution and discrimination continued in employment and housing, the political arena was brighter for blacks. They were voting in large numbers and thus were able to secure the election of local and state candidates who were less hostile to black aspirations. In 1971, a coalition of black and Cajun votes was able to elect a liberal, populist governor. Once the new administration assumed office in 1972, existing segregation statutes were repealed, and in the following year, a new constitution was written with guarantees of equality and equal protection for all citizens of the state. By 1974, de jure segregation was dead and blacks had the means to assure that its demise was permanent. Although the thornier issue of de facto segregation remained unresolved, there was hope and promise that it, too, would be eradicated one day