4,112 research outputs found
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
W^+W^+ plus dijet production in the POWHEGBOX
We present an implementation of the calculation of the production of W^+W^+
plus two jets at hadron colliders, at next-to-leading order (NLO) in QCD, in
the POWHEG framework, which is a method that allows the interfacing of NLO
calculations to shower Monte Carlo programs. This is the first 2 -> 4 process
to be described to NLO accuracy within a shower Monte Carlo framework. The
implementation was built within the POWHEGBOX package. We discuss a few
technical improvements that were needed in the POWHEGBOX to deal with the
computer intensive nature of the NLO calculation, and argue that further
improvements are possible, so that the method can match the complexity that is
reached today in NLO calculations. We have interfaced our POWHEG implementation
with PYTHIA and HERWIG, and present some phenomenological results, discussing
similarities and differences between the pure NLO and the POWHEG+PYTHIA
calculation both for inclusive and more exclusive distributions. We have made
the relevant code available at the POWHEGBOX web site.Comment: 16 pages, 5 figure
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