Viscid/inviscid interaction analysis of thrust augmenting ejectors

A method was developed for calculating the static performance of thrust augmenting ejectors by matching a viscous solution for the flow through the ejector to an inviscid solution for the flow outside the ejector. A two dimensional analysis utilizing a turbulence kinetic energy model is used to calculate the rate of entrainment by the jets. Vortex panel methods are then used with the requirement that the ejector shroud must be a streamline of the flow induced by the jets to determine the strength of circulation generated around the shroud. In effect, the ejector shroud is considered to be flying in the velocity field of the jets. The solution is converged by iterating between the rate of entrainment and the strength of the circulation. This approach offers the advantage of including external influences on the flow through the ejector. Comparisons with data are presented for an ejector having a single central nozzle and Coanda jet on the walls. The accuracy of the matched solution is found to be especially sensitive to the jet flap effect of the flow just downstream of the ejector exit

ttˉbbˉt\bar{t}b\bar{b} hadroproduction with massive bottom quarks with PowHel

The associated production of top-antitop-bottom-antibottom quarks is a relevant irreducible background for Higgs boson analyses in the top-antitop-Higgs production channel, with Higgs decaying into a bottom-antibottom quark pair. We implement this process in the PowHel event generator, considering the bottom quarks as massive in all steps of the computation which involves hard-scattering matrix-elements in the 4-flavour number scheme combined with 4-flavour Parton Distribution Functions. Predictions with NLO QCD + Parton Shower accuracy, as obtained by PowHel + PYTHIA, are compared to those which resulted from a previous PowHel implementation with hard-scattering matrix-elements in the 5-flavour number scheme, considering as a baseline the example of a realistic analysis of top-antitop hadroproduction with additional $b$-jet activity, performed by the CMS collaboration at the Large Hadron Collider.Comment: 9 pages, 6 figure

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

A room-temperature alternating current susceptometer - Data analysis, calibration, and test

An AC susceptometer operating in the range of 10 Hz to 100 kHz and at room temperature is designed, built, calibrated and used to characterize the magnetic behaviour of coated magnetic nanoparticles. Other weakly magnetic materials (in amounts of some millilitres) can be analyzed as well. The setup makes use of a DAQ-based acquisition system in order to determine the amplitude and the phase of the sample magnetization as a function of the frequency of the driving magnetic field, which is powered by a digital waveform generator. A specific acquisition strategy makes the response directly proportional to the sample susceptibility, taking advantage of the differential nature of the coil assembly. A calibration method based on conductive samples is developed.Comment: 8 pages, 7 figures, 19 ref

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

Making U.S. Readers in the Early Twentieth Century

“Making U.S. Readers in the Early Twentieth Century” considers how definitions of “reading” and “being a reader” circulated through mass-mediated textual materials associated with three of the period’s increasingly influential institutions: the school, the newspaper, and the library. For a period that thought deeply about the implications of expanding networks of literacy and print, I assemble a formally and disciplinarily diverse archive of materials that represents the breadth of this period’s public thinking on reading. By closely reading standardized silent reading tests, beginning reading primers for illiterate adults, newspaper book reviews, and library publicity materials, I distill the complex set of practices, attitudes, and behaviors—some textual, many not—that signified “being a reader” for different types of subjects. As these materials teach to their varied audiences, “reading” is not merely an internalized, personal practice, but is a highly contingent form of sociality, a way of understanding one’s position in a world that is increasingly organized by print. As I show by paying special attention to invocations of non-reading, the stakes for reading in this period were high, especially as “being a reader” became a mode of modernization, civility, and American citizenship. As a contribution to the history of reading, “Making U.S. Readers” provides a model for recovering specific meanings attached to reading in the past by looking beyond the inner experiences of individual readers to the larger structures of thought and feeling that gave individual reading practices their social significance. A key insight that stems from this method is the importance of “non-reading” to a history of reading, particularly in times in which “reading” is highly politicized. As a contribution to literary history, this dissertation offers a way of conceiving of literary studies itself as a project of “making readers,” one that can find many of its ideological ancestors in the non-literary projects of the early twentieth century. Rather than set literary reading apart from more obviously instrumental modes of reading, I suggest that we should embrace the instrumentality of our reading practices and ask unambiguously what types of readers we hope “literary reading” can make.PhDEnglish Language and LiteratureUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/133248/1/bevilacq_1.pd

Helac-nlo

Based on the OPP technique and the HELAC framework, HELAC-1LOOP is a program that is capable of numerically evaluating QCD virtual corrections to scattering amplitudes. A detailed presentation of the algorithm is given, along with instructions to run the code and benchmark results. The program is part of the HELAC-NLO framework that allows for a complete evaluation of QCD NLO corrections.Comment: minor text revisions, version to appear in Comput.Phys.Commu

The Only Architectural Testimony of an 18th Century Italian Gordonia-Style Miniature Theatre: An Acoustic Survey of the Monte Castello di Vibio Theatre

The acoustic characteristics and spatial features of the world’s only surviving Italianate Gordonia-style miniature theatre, one of the smallest theatres in the world, have inspired the author to analyse the acoustic behaviour of the Monte Castello di Vibio theatre, also called “Teatro della Concordia”. In this paper, the geometric and architectural features of this historical and unique performing art space were first reproduced, considering that these features are essential factors affecting acoustic characteristics. Subsequently, the acoustic measurements were taken throughout the stall and inside some selected boxes, and their main parameters were acoustically characterised according to ISO 3382-1. Lastly, the main acoustic parameters of the Monte Castello di Vibio theatre were compared to those of the 1763 theatre in Bologna, which is also a miniature theatre of similar size. The aim is to explore the main influences on the acoustic parameters of miniature theatres, and the results show that the plan layout of the theatre and interior decoration are the main factors influencing the acoustic characteristics rather than volume. Preserving the acoustic features of this unique heritage building is also seen as one of the goals of this paper

Acoustic Characterization and Quality Assessment of Cremona’s Ponchielli Theater

The Ponchielli theater of Cremona was built in 1808 after a fire destroyed the old wooden structure. The interior, the architecture and the shape of the plan layout are reminiscent of the Teatro alla Scala, Milan, a masterpiece by the architect Piermarini, albeit on a smaller scale. The four orders of balconies crowned by the top gallery are typical features of a 19th Century Italian Opera theater. Acoustic measurements have been undertaken across the stalls and in some selected boxes according to ISO 3382. The main acoustic parameters resulting from the measurements have been used for the acoustic calibration of a 3D model representing the Ponchielli theater. The calibration has been used to compare different scenarios involving the acoustic response of the main hall at 50% and 100% occupancy. The outcomes indicate that no significant change can be detected when the seats are provided with robust upholstery, which can be considered a positive result, especially for the actors who are not forced to change their effort between rehearsal and live performance. In order to contextualize the measured values in relation to the optimal ones, a comparison with other Italian Opera theaters provided with similar architectural characteristics has been carried out. Overall, the findings indicate that the acoustics of the Ponchielli theater are suitable for both music and speech in line with the other selected theaters, as these places were mainly created for multifunctional purposes in the 19th Century