RF radiation hazards to space station personnel

RF radiation hazards to space station personne

Comparison of acoustic and strain gauge techniques for crack closure measurements

A quantitative study on the systems performances of the COD gauge and the acoustic transmission techniques to elastic deformation of part-through crack and compact tension specimens has been conducted. It is shown that the two instruments measure two completely different quantities: The COD gauge yields information on the length change of the specimen whereas the acoustic technique is sensitive directly to the amount of contract area between two surfaces, interfering with the acoustic signal. In another series of experiments, compression tests on parts with specifically prepared surfaces were performed so that the surface contact area could be correlated with the transmitted acoustic signal, as well as the acoustic with the COD gauge signal. A linear relation between contact area and COD gauge signal was obtained until full contact had been established

Competition in the Pacific Basin

I am going to focus on the future, but first we must glance bricf1y at the era immediately following World War II. Competition in the Pacific basin can reasonably be divided in to three separate areas-military, political, and economic

Exploring the Use of Technology to Support Literacy of Sixth Grade Students with Reading Disabilities

University of Missouri-St. Louis College of Education Ed.D. Learning Community of Practice Curriculum and Instruction Exploring the Use of Technology to Support Literacy of Sixth Grade Students with Reading Disabilities Jaime R. Ball-Inman Abstract The degree to which the utilization of technology supports the academic achievement of sixth grade students with reading disabilities was examined using a quantitative research design. The data analysis involved the results from the Educational Technology Assessment Program to measure achievement. The Standardized Test for the Assessment of Reading (STAR) provided 2015-2016 scores regarding academic accomplishment of middle school students with reading disabilities. The central research question was developed based on the current literature on the impact technology can have on student academic achievement (Grinager, 2006). Using a specially designed survey, the researcher examined the teachers’ understanding of educational technology and what technology was used to support learning in students with reading disabilities was determined. Along with the technology used by teachers, student reading scores, as well parent and student perception of technology use surveys were used to answer the research questions. In comparing data sources (STAR assessment and surveys), the degree to which technology supports student academic achievement was described

Predicting U.S. Jet Fighter Aircraft Introductions from 1944 to 1982: A Dogfight Between Regression and TFDEA

Since its inception in 2001, technology forecasting using data envelopment analysis (TFDEA) has been used with a number of applications. This paper presents a formal comparison of TFDEA to a previously published application from Technological Forecasting and Social Change by Joseph Martino. Using the data and Martino’s multiple regression model, we compare results obtained from TFDEA to those previously published. Both techniques predict the first flights of fighter jets introduced between 1960 and 1982 by using the first flights of aircraft introduced between 1944 and 1960. TFDEA was found to better predict the first flight dates than the forecast using multiple regression. These results indicate that TFDEA may be a powerful new technique for predicting complex technological trends and time to market for new products

Improving Time to Market Forecasts: A Comparison of Two Technology Forecasting Techniques for Predicting U.S. Fighter Jet Introductions From 1944 to 1982

Since its origin in 2001, technology forecasting using data envelopment analysis (TFDEA) has been tested with a number of applications. This paper uses a previously published technology forecast comparison of U.S. fighter jets between the years 1944 and 1982 to compare TFDEA to basic regression. Both techniques use aircraft introduced between 1944 and 1960 to predict the first flights of those fighters introduced between 1960 and 1982. TFDEA was found to better predict the first flight dates than the forecast using regression. These results indicate that TFDEA may be a powerful new technique for predicting complex technological trends and time to market for new product

Specific Adherence of Escherichia coli (Strain RDEC-1) to Membranous (M) Cells of the Peyer\u27s Patch in Escherichia coli Diarrhea in the Rabbit

The RDEC-1 strain Escherichia coli is an enteroadherent bacterium that produces diarrhea in the rabbit. A histopathologically similar disease has been described in humans. The RDEC-1 bacterium adheres to the epithelium of lymphoid follicles in rabbit ileal Peyer\u27s patches by 4 h postinoculation, 3-4 d before its adherence to absorptive epithelium. The purpose of this study was to determine whether the RDEC-1 bacterium adheres to a specific cell type in the lymphoid follicle epithelium. RDEC-1 bacteria were given in a dose of 2 X 10^6 by the orogastric route to postweanling rabbits. The distal ileal Peyer\u27s patch, taken from 5 control rabbits and 43 rabbits at intervals in the first 24 h postinoculation, was examined by routine and high-voltage electron microscopy. The RDEC-1 bacterium adhered specifically to M (membranous) rather than absorptive epithelial cells of the lymphoid follicle epithelium. Further understanding of how the bacterium attaches to M cells, which transport antigens to intraepithelial lymphocytes, could be useful in designing vaccines to protect mucosal surfaces

Peyer\u27s Patch Lymphoid Follicle Epithelial Adherence of a Rabbit Enteropathogenic Escherichia coli (Strain RDEC-1) Role of Plasmid-Mediated Pili in Initial Adherence

Escherichia coli (strain RDEC- 1) adheres to M cells of rabbit Peyer\u27s patch lymphoid follicle epithelium. The RDEC-1 strain contains an 85 X 10^6 D plasmid that codes for pili, which, when purified, adhere to gut absorptive epithelium. This study compared the in vivo lymphoid follicle adherence of the RDEC- 1 strain with that of a Shigella flexneri (ShD 15) that contained the 85 X 10^6 D plasmid and expressed the RDEC-l pili, a control E. coli, and a control S. flexneri (ShD 12). The bacteria were given in a dose of 10^10 to 0.7-1.1 kg rabbits. The rabbits were sacrificed at 2, 4, 6, and 12 h postinoculation. Peyer\u27s patch tissue was examined by electronmicroscopy and direct fluorescence microscopy. The piliated ShD 15 and RDEC-1 bacteria adhered in large numbers at 2 and 4 h postinoculation, but only the RDEC1 strain persisted and increased in numbers past that time. Control strains did not adhere. The ShD 15 strain adhered to and was rapidly taken into M cells, precipitating an acute inflammatory reaction within the follicle and adjacent lumen. Initial lymphoid follicle M cell adherence of the ShD 15 strain was associated with the possession of the adherence pilus plasmid. The failure of the ShD 15 strain to survive and colonize the lymph follicle epithelium contrasts with the success of the RDEC-1 strain and indicates that the RDEC-1 strain possesses virulence factors in addition to pili