Academic literature on the topic 'LD5655.V851 1996.M494'

A series of perfectly alternating polyimide/ poly(dimethylsiloxane) microphase separated block copolymers ranging from 0-50 wgt. % poly(dimethylsiloxane) have been measured for permeability characteristics. The polyimide segment of the copolymers was based on oxydiphthalicdianhydride (ODPA) and 1,4-Bis(4-amino-1,1- dimethylbenzyl)benzene (Bis P). The polysiloxane was an aminopropyl terminated poly(dimethylsiloxane). Randomly segmented block copolymers of =20 wet. % poly(dimethylsiloxane) with different segment lengths were also studied, based on the same materials for the sake of comparison with the perfectly alternating versions of the same block copolymers. Permeability measurements were performed on tough, microphase separated, transparent films with O₂, N₂, CH₄, and CO₂ gases in that order. The effects of the chemical composition and block lengths on permeability coefficients and selectivity values were evaluated. The permeability of copolymer films to gases was found to be highly sensitive to the morphology of the copolymer. The morphology was found to be controlled by varying the amount and the segment length of each component and this allowed for fine control of the permeability characteristics. Conversely, the measurement of permeability characteristics can lead to more information about the morphology of complicated microphase separated block copolymers.<br>Master of Science

The major purpose of this study was to analyze the productivity of the clinical dietitian in order to develop appropriate models for measurement of productivity of the clinical dietitian. Due to the lack of research on productivity in the service sector, a modified Delphi Technique was used to identify appropriate measures of input and output for the clinical dietitian. The information gathered from the Delphi Technique was used to develop a survey designed to measure the productivity of the clinical dietitian. Two hundred eighty-three participants responded to the survey. Five measures of productivity were developed. They were: (1) hours in direct patient care/total hours worked (2) hours in indirect patient care/ total hours worked (3) hours in nonpatient care/ total hours worked (4) hours spent in direct plus indiiect patient care/total hours worked and (5) the activity level in nonproductive activities. The independent variables used in this study were: (1) patient load of the clinical dietitian (2) years of experience of the clinical dietitian (3) the allocation of time to tasks performed by the clinical dietitian (4) consultation methods used by the clinical dietitian (5) size of the hospital (6) employment status of the clinical dietitian (7) mission of the hospital (8) percent occupancy of the hospital and <9> percent of the budget generated by Medicare patients. Results of the analyses showed that dietitians were spending a variety of time in the thirty-three identified activities. They had a high activity level in performing diet histories, individual diet instructions, performing nutritional assessments, and reviewing and recording in medical records. Tasks involving low levels of activity were taking anthopometric measurements, reading professional literature and attending professional conferences. To fully investigate the relationship between the measures of productivity (dependent variables) and the independent variables stepwise multiple linear regression in the SAS statistical program was used. Analyses revealed two models appropriate for measuring the productivity. These models involved nonpatient care and nonproductive activities. The development of these models overcame the difficulty discussed in the service literature of developing direct measures of productivity of employees in the service sector.<br>Ph. D.