An evaluation of grease type ball bearing lubricants operating in various environments

Because many future spacecraft or space stations will require mechanisms to operate for long periods of time in environments which are adverse to most bearing lubricants, a series of tests has been completed to evaluate 38 grease type lubricants in R-4 size bearings in five different environments for a 1 year period. Four repetitions of each test were made to provide statistical samples. These tests were also used to select four lubricants for 5 year tests in selected environments with five repetitions of each test for statistical samples. In this completed program, 172 test sets have been completed. The three 5 year tests in: (1) continuous operation and (2) start stop operation, with both in vacuum at ambient temperatures, and (3) continuous vacuum operation at 93.3 C have been completed. In both the 1 year and 5 year tests, the best results in all environments have been obtained with a high viscosity index perfluoroalkylpolyether (PFPE) grease

An evaluation of grease type ball bearing lubricants operating in various environments

Grease type lubricants in bearings were evaluated in five different adverse environments for a one year period. Four repetitions of each test were made to provide statistical samples. These tests were then used to select four lubricants for five year tests in selected environments with five repetitions of each test for statistical samples. Three five year tests were started in (1) continuous operation; (2) start-stop operation, with both in vacuum at ambient temperatures; and (3) continuous operation at 93.3 C. To date, in the one year tests, the best results in all environments were obtained with a high viscosity index perfluoroalkylpolyether grease

An evaluation of grease type ball bearing lubricants operating in various environments

Because many future spacecraft or space stations will require mechanisms to operate for long periods of time in environments which are adverse to most bearing lubricants, a series of tests is continuing to evaluate 38 grease type lubricants in R-4 size bearings in five different environments for a 1 year period. Four repetitions of each test are made to provide statistical samples. These tests were used to select four lubricants for 5 year tests in selected environments with five repetitions of each test for statistical samples. At the present time, 100 test sets are completed and 22 test sets are underway. Three 5 year tests were started in (1) continuous operation and (2) start-stop operation, with both in vacuum at ambient temperatures, and (3) continuous operation at 93.3 C. In the 1 year tests the best results to date in all environments were obtained with a high viscosity index perfluoroalkylpolyether (PFPE) grease

The IDEA and the Use of Mediation and Collaborative Dispute Resolution in Due Process Disputes

This Comment discusses the future of alternative dispute resolution in special education conflicts by first examining a brief history of the IDEA and the areas it covers. Due process complaints under the IDEA and mediation as a solution to due process complaints will then be addressed. Then, it will focus on mediation and its impact on parents and schools, particularly the advantages and disadvantages of mediation, and the presence of attorneys in mediation. Finally, it will look towards collaborative law, when two attorneys and their clients collaborate to reach an agreement, and the future of collaborative dispute resolution in the special education field. This Comment will show that mediation has a better chance of succeeding when attorneys represent both parties. Furthermore, collaborative dispute resolution may be an ideal solution that reaps the benefits of alternative dispute resolution while avoiding the drawbacks of traditional mediation in special education disputes

Immigration, assimilation, and language : a case study of ESL programs in Louisville, Kentucky.

This thesis examined the structure and processes of several different organizations that offer English as a Second Language (ESL) classes in one Kentucky county. The purpose of the study was to analyze the structure of the organizations, and then analyze how the structure affects their approach to teaching ESL. There were three expectations going into this study: the ESL programs would be segregated and distinct from one another, they would be challenged to teach a diverse clientele, and the services would be strongly student-oriented. Semi-structured interviews were conducted with six program coordinators and two teachers across six different organizations. The findings revealed that although the programs do operate independently, they are much more connected than initially expected. Due to recent trends in immigration and assimilation patterns, the ESL programs teach classes holistically, based on the needs of a diverse student population