Design and test of a prototype scale ejector wing

A two dimensional momentum integral analysis was used to examine the effect of changing inlet area ratio, diffuser area ratio, and the ratio of ejector length to width. A relatively wide range of these parameters was considered. It was found that for constant inlet area ratio the augmentation increases with the ejector length, and for constant length: width ratio the augmentation increases with inlet area ratio. Scale model tests were used to verify these trends and to examine th effect of aspect ratio. On the basis of these results, an ejector configuration was selected for fabrication and testing at a scale representative of an ejector wing aircraft. The test ejector was powered by a Pratt-Whitney F401 engine developing approximately 12,000 pounds of thrust. The results of preliminary tests indicate that the ejector develops a thrust augmentation ratio better than 1.65

Genotypic and Phenotypic Heterogeneity in Alicyclobacillus acidoterrestris: A Contribution to Species Characterization.

Alicyclobacillus acidoterrestris is the main cause of most spoilage problems in fruit juices and acidic products. Since soil borne species often contaminate fruit juices and do not need strict extreme requirements for survival, it is a great concern to investigate whether and how soil species could evolve from their ecological niches in microbial community to new environments as fruit juices. In this study, 23 isolates of thermo-acidophilic, spore-forming bacteria from soil were characterized by cultural and molecular methods. In addition, 2 strains isolated from a spoilage incident in pear juice were typed. Strains phenotyping showed that they could be grouped into 3 different clusters, and some isolates showed identical or quite similar patterns. Analyzing pH and temperature ranges for growth, the majority of strains were able to grow at values described for many species of Alicyclobacillus. Qualitative utilization of lysine, arginine and indole production from tryptophan revealed, for the first time, deamination of lysine and decarboxylation of arginine. Resistance to 5% NaCl as well as the ability to hydrolyze starch and gelatin, nitrate reduction, catalase and oxidase activities confirmed literature evidences. Examining of 16S rRNA, showed that isolates were divided into three blocks represented by effectively soil species and strains that are moving from soil to other possible growing source characterized by parameters that could strongly influence bacterial survival. RAPD PCR technique evidenced a great variability in banding patterns and, although it was not possible to obtain genotypically well-distinguished groups, it was feasible to appreciate genetic similarity between some strains. In conclusion, the investigation of a microbial community entails a combination of metagenomic and classic culturedependent approaches to expand our knowledge about Alicyclobacillus and to look for new subspecies

Performance of screening for aneuploidies by cell-free DNA analysis of maternal blood in twin pregnancies

Objectives To report clinical implementation of cell‐free DNA (cfDNA) analysis of maternal blood in screening for trisomies 21, 18 and 13 in twin pregnancies and examine variables that could influence the failure rate of the test. Methods cfDNA testing was performed in 515 twin pregnancies at 10–28 weeks' gestation. The failure rate of the test to provide results was compared with that in 1847 singleton pregnancies, and logistic regression analysis was used to determine which factors among maternal and pregnancy characteristics were significant predictors of test failure. Results Failure rate of the cfDNA test at first sampling was 1.7% in singletons and 5.6% in twins. Of those with a test result, the median fetal fraction in twins was 8.7% (range, 4.1–30.0%), which was lower than that in singletons (11.7% (range, 4.0–38.9%)). Multivariable regression analysis demonstrated that twin pregnancy, higher maternal weight and conception by in‐vitro fertilization provided significant independent prediction of test failure. Follow‐up was available in 351 (68.2%) of the twin pregnancies and comprised 334 with euploid fetuses, 12 discordant for trisomy 21 and five discordant for trisomy 18. In all 323 euploid cases with a result, the risk score for each trisomy was < 1:10 000. In 11 of the 12 cases with trisomy 21 and in the five with trisomy 18, the cfDNA test gave a high‐risk result, but in one case of trisomy 21, the score was < 1:10 000. Conclusion In twin pregnancies screening by cfDNA testing is feasible, but the failure rate is higher and detection rate may be lower than in singletons

Advanced Tethered Application and Related Technologies

APPLICATION OF TETHERED SYSTEMS ARE SUBJECT OF A NUMBER OF FEASIBILITY STUDIES AGlNG ACTUALLY PERFORMED BOTH IN US AND IN ITALY. THE ITALIAN PSN (PIANO SPAZIALE NAZIONALE) HAS AWARDED TO AERITALIA A LARGE STUDY FDR THE IDENTIFICATION OF THESE APPLICATIONS THAT lNDICATE PROMISES OF SCIENTIFIC AND APPLIED R~SEARCH AND FOR THE DEFINITION OF THE GOALS OF DEMONSTRATION FLIGHTS FOR TESTING THE FUNDAMENTAL FEATURES OF TH~ SELECTED POTENTIAL CONCEPTS

SPACE-TIME ESTIMATION AND PREDICTION UNDER FIXED-DOMAIN ASYMPTOTICS WITH COMPACTLY SUPPORTED COVARIANCE FUNCTIONS

We study the estimation and prediction of Gaussian processes with spacetime covariance models belonging to the dynamical generalized Wendland (DGW) family, under fixed-domain asymptotics. Such a class is nonseparable, has dynamical compact supports, and parameterizes differentiability at the origin similarly to the space-time Matern class.Our results are presented in two parts. First, we establish the strong consistency and asymptotic normality for the maximum likelihood estimator of the microergodic parameter associated with the DGW covariance model, under fixed-domain asymptotics. The second part focuses on optimal kriging prediction under the DGW model and an asymptotically correct estimation of the mean squared error using a misspecified model. Our theoretical results are, in turn, based on the equivalence of Gaussian measures under some given families of space-time covariance functions, where both space or time are compact. The technical results are provided in the online Supplementary material