The continuing need for accelerators of increasingly sophisticated characteristics requires a great variety of rf sources to provide the energy used by these accelerators. The present status of gridded tubes will be reviewed briefly. Klystrons, which are used in most large accelerators, will be considered in some detail. Their limitations in power and frequency will be reviewed and a study of t...

We have calculated two new sets of weights applicable to the General Household Survey (GHS) from 1979 to 2007. One of these is for use with any general analysis of GHS topics and the second is designed for analyses of data collected in the Family Information section. The methods used follow closely those employed by ONS from 1996 onwards. The performance of the weights is assessed in estimating...

This index covers all items-papers, correspondence, reviews, etc.that appeared in this periodical dunng 1979, and items from prior years that were commented upon or corrected in 1979. The index is divided into an Author Index and a Subject Index, both arranged alphabetically. The Author Index contains the primary entry for each item; this entry is listed under the name of the first author and i...

Every year many workers become sick or suffer accidents away from their jobs and so cannot work for temporary periods ranging from a few days to several months. Although there is no Federal social insurance program to protect against this risk, the majority of workers are nevertheless protected through State programs, industry programs, or private sector programs. Five States (California, Hawai...

I develop an implicit finite-difference migration method for vertical transversely isotropic (VTI) media with laterally varying anisotropy parameters. I approximate the dispersion relation of VTI media with a rational function series, the coefficients of which are estimated by least-squares optimization. These coefficients are functions of Thomsen anisotropy parameters. They are calculated and ...

The implantation rate of cardiac pacemakers in Northern Ireland rose from 55.8 per million population in 1979 to over 180 per million in 1988, with the emergence of a second pacemaker implantation centre. However, the implantation rate in Northern Ireland remains less than that of many other countries. Over the period complete heart block fell as an indication from 45% to 34% and sinus node dis...

Part of the process of scientific discovery is linguistic. It is not only necessary for scientists to observe and discover phenomena, but also to name them. Thus, the coining of new terms (neologisms) is very important to the growth of science. During a recent discussion with Columbia University Professors Robert K. Merton and Harriet Zuckerman, a new and, I believe, useful term was born. For y...