The Effect of Ice Formations on Propeller Performance

Measurements of propeller efficiency loss due to ice formation are supplemented by an analysis to establish the magnitude of efficiency losses to be anticipated during flight in icing conditions. The measurements were made during flight in natural icing conditions; whereas the analysis consisted of an investIgation of changes in blade-section aerodynamic characteristics caused by ice formation and the resulting propeller efficiency changes. Agreement in the order of magnitude of eff 1- ciency losses to be expected is obtained between measured and analytical results. The results indicate that, in general, efficiency losses can be expected to be less than 10 percent; whereas maximum losses, which will be encountered only rarely, may be as high as 15 or 20 percent. Reported. losses larger than 15 or 20 percent, based on reductions in airplane performance, probably are due to ice accretions on other parts of the airplane. Blade-element theory is used in the analytical treatment, and calculations are made to show the degree to which the aerodynamic characteristics of a blade section. must be altered to produce various propeller efficiency losses. The effects of ice accretions on airfoil-section characteristics at subcritical speeds and their influence on drag-divergence Mach number are examined, and. the attendant maximum efficiency losses are computed. The effect of kinetic heating on the radial extent of ice formation is considered, and its influence on required length of blade heating shoes is discussed. It is demonstrated how the efficiency loss resulting from an icing encounter is influenced by the decisions of the pilot in adjusting the engine and propeller controls

Towards a Common Center: Locating Common Characteristics of African Centeredness in an Independent African Centered Learning Environment

As a culturally relevant alternative to traditional public school environments, Independent African Centered schools feature a particular type of culturally relevant pedagogy. This study explored the teachers’ and administrator’s perceptions and applications of African Centered pedagogy in an African Centered school. Interviews, observations and a document review served as the source of data for this study. This basic interpretive study utilized a qualitative research design to explore the perceptions and application of African Centeredness among the participants. An analysis of the data revealed categories and themes related to the school’s mission and the participants’ perceptions and performance of African-centered pedagogy. Three general conclusions were drawn from the findings. Implications for theory, study limitations and recommendations for future research are provided

Soul In A Can : Exploring How Black Male Students And Artists Navigate The Constraints Of Urban Classrooms And The Music Industry

ABSTRACT “Soul in a Can” builds on research that explores Black male identity and containment within structures where racial power is distributed inequitably. This research responds to a need for more diversity regarding the range of Black male voices explored in academic literature. This arts-based qualitative research used a case study design to explore how Black male students and artists navigate the constraints of urban classrooms and the music industry. The following questions guided this exploration: How do contemporary professional Black male recording artists navigate the recording industry’s tendency to restrain their personal “voice” and creative agency in the process of commodifying their talents? How do Black male youth navigate classroom spaces to maintain their personal “voice” and creative agency? Are there similarities between the experiences of Black male artists and Black males in the education system and how they navigate the power differential they face? Data is comprised of participant interviews with six Black males including three students and three professional recording artists. Interviews were conducted in a two-phase process that respectively focused on participant rendered key metaphorsand sound worlds.More specifically, the researcher employed a Critical Race Theory frame emphasizing two of its components— “whiteness as property” and “interest convergence”—along with an Arts-Based Methodology which employed a fugue of elements in order to creatively collect and analyze data. Significantly the study chronicles and offers insight into the Black experience and resistance in two sites—the music industry and classrooms—as lived by Black male artists and students. Notably, these two sites have not been adequately examined in relation to one another. Findings reveal that participants across sites navigated inequitable power through a four-phase process— “I’ll figure it out,” “Peep Game,” “New Attitude,” and “Experience is the best teacher”—in which experiential knowledge was refined and sharpened; this enabled participants to successfully survive endemic racism, but questions remain regarding what the author terms dysconscious acquiescenceor the apparent belief that “surviving” is a substitute for “thriving.” Implications abound regarding the impact of structural containment on Black identity development, cultural authenticity, and expression

The Ursinus Weekly, November 2, 1942

First forum hears political, economic stakes of the war • Unity in diversity will be subject of interdenominational conference • Council president tells vespers of religion in college • Fathers\u27 Day banquet to feature addresses by Steward and Ditter • Praise the lord chaplain attended college during \u2728 • Old timers\u27 day to feature Gettysburg game and dance • Curtain Club books play tryouts for Tuesday night • Library increases rake-off on books that are overdue • English Club schedules book review for tonight • Former college nurse attending U.S. Army somewhere in England • Detwiler, Brunner elected to fill council vacancies • Bayne to address chemists • Bears will be out for dragon meat in first home game on Saturday • Three coeds place on all-college team • One fifty pounders to begin scrimmage for opening games • Bakermen drop close 1-0 decision to Swarthmore • Ursinus, Bryn Mawr battle to 2-2 tie • Bryn Mawr jayvees wallop Ursinus coeds 7-1 in opener • Gettysburg whips Drexel by score of 18-0 Saturday • Lady with the Packard Clipper and the dog -- that\u27s Miss Snell • Haverford booters defeat bears 10-0 • Sixty-five couples attend varsity dance on Saturday • IRC adopts plan to study post war reconstructionshttps://digitalcommons.ursinus.edu/weekly/1743/thumbnail.jp

Measurement of triple gauge boson couplings from W⁺W⁻ production at LEP energies up to 189 GeV

A measurement of triple gauge boson couplings is presented, based on W-pair data recorded by the OPAL detector at LEP during 1998 at a centre-of-mass energy of 189 GeV with an integrated luminosity of 183 pb⁻¹. After combining with our previous measurements at centre-of-mass energies of 161–183 GeV we obtain κ = 0.97_{-0.16}^{+0.20}, g_{1}^{z} = 0.991_{-0.057}^{+0.060} and λ = -0.110_{-0.055}^{+0.058}, where the errors include both statistical and systematic uncertainties and each coupling is determined by setting the other two couplings to their Standard Model values. These results are consistent with the Standard Model expectations

Using Long-Term Volunteer Records to Examine Dormouse (Muscardinusavellanarius) Nestbox Selection.

Within ecology, there are unanswered questions about species-habitat interactions, which could potentially be resolved by a pragmatic analysis of a long-term volunteer-collected dataset. Here, we analysed 18 years of volunteer-collected data from a UK dormouse nestbox monitoring programme to determine the influence of habitat variables on nestbox choice by common dormice (Muscardinusavellanarius). We measured a range of habitat variables in a coppiced woodland in Gloucestershire, UK, and analysed these in relation to dormouse nestbox occupancy records (by dormice, other small mammals, and birds) collected by volunteers. While some characteristics of the woodland had changed over 18 years, simple transformation of the data and interpretation of the results indicated that the dataset was informative. Using stepwise regressions, multiple environmental and ecological factors were found to determine nestbox selection. Distance from the edge of the wood was the most influential (this did not change over 18 years), with boxes in the woodland interior being selected preferentially. There was a significant negative relationship with the presence of ferns (indicative of damp shady conditions). The presence of oak (a long-lived species), and the clumped structural complexity of the canopy were also important factors in the final model. There was no evidence of competition between dormice and birds or other mammals. The results provide greater understanding of artificial dormouse nest-site requirements and indicate that, in terms of habitat selection, long-term volunteer-collected datasets contribute usefully to understanding the requirements of species with an important conservation status

The Ursinus Weekly, October 5, 1942

Over 135 students speed graduation in summer school • Abraham Hendricks succumbs at home after long illness • President McClure greets largest new enrollment Thursday in chapel • Founders\u27 Day program to honor Dr. Pfahler in dedication ceremony • College buildings to close at 5:30 • Work-study plan attracts 20 men • College opens buildings to 3 summer conclaves • Freshmen stagger through first week of mysteries at Ursinus • Miss Beck takes post as assistant librarian • Ursinus to participate in student war loan program • Swartley sets deadline • Five delegates attend Kanestaki conference • Y handbook guides puzzled freshmen • Letter received from Y\u27s Spanish refugee • Dr. McClure attends Colgate inauguration • The Ursinus College faculty • Here they are - largest enrollment of new students! • Summer sports feature intramurals and softball • Thirty-eight men out for football as second week of practice begins • Stevens is completing plans for inauguration of 150-lb. grid league • Grid schedule to include two home, two away games • Eight holdovers brighten outlook for girls hockey • Mules meet G-burg • Stevens enters his second year optimistically • Over twenty veterans report for soccer practice • Plea for humility made by Snyder, former Y prexy • R. C. Bartman promoted to captain in Navy • Carrying on the traditionhttps://digitalcommons.ursinus.edu/weekly/1739/thumbnail.jp

A Measurement of Rb using a Double Tagging Method

The fraction of Z to bbbar events in hadronic Z decays has been measured by the OPAL experiment using the data collected at LEP between 1992 and 1995. The Z to bbbar decays were tagged using displaced secondary vertices, and high momentum electrons and muons. Systematic uncertainties were reduced by measuring the b-tagging efficiency using a double tagging technique. Efficiency correlations between opposite hemispheres of an event are small, and are well understood through comparisons between real and simulated data samples. A value of Rb = 0.2178 +- 0.0011 +- 0.0013 was obtained, where the first error is statistical and the second systematic. The uncertainty on Rc, the fraction of Z to ccbar events in hadronic Z decays, is not included in the errors. The dependence on Rc is Delta(Rb)/Rb = -0.056*Delta(Rc)/Rc where Delta(Rc) is the deviation of Rc from the value 0.172 predicted by the Standard Model. The result for Rb agrees with the value of 0.2155 +- 0.0003 predicted by the Standard Model.Comment: 42 pages, LaTeX, 14 eps figures included, submitted to European Physical Journal

Seroprevalence following the second wave of pandemic 2009 H1N1 influenza in Pittsburgh, PA, USA

Background: In April 2009, a new pandemic strain of influenza infected thousands of persons in Mexico and the United States and spread rapidly worldwide. During the ensuing summer months, cases ebbed in the Northern Hemisphere while the Southern Hemisphere experienced a typical influenza season dominated by the novel strain. In the fall, a second wave of pandemic H1N1 swept through the United States, peaking in most parts of the country by mid October and returning to baseline levels by early December. The objective was to determine the seroprevalence of antibodies against the pandemic 2009 H1N1 influenza strain by decade of birth among Pittsburgh-area residents. Methods and Findings: Anonymous blood samples were obtained from clinical laboratories and categorized by decade of birth from 1920-2009. Using hemagglutination-inhibition assays, approximately 100 samples per decade (n = 846) were tested from blood samples drawn on hospital and clinic patients in mid-November and early December 2009. Age specific seroprevalences against pandemic H1N1 (A/California/7/2009) were measured and compared to seroprevalences against H1N1 strains that had previously circulated in the population in 2007, 1957, and 1918. (A/Brisbane/59/2007, A/Denver/1/ 1957, and A/South Carolina/1/1918). Stored serum samples from healthy, young adults from 2008 were used as a control group (n = 100). Seroprevalences against pandemic 2009 H1N1 influenza varied by age group, with children age 10-19 years having the highest seroprevalence (45%), and persons age 70-79 years having the lowest (5%). The baseline seroprevalence among control samples from 18-24 year-olds was 6%. Overall seroprevalence against pandemic H1N1 across all age groups was approximately 21%. Conclusions: After the peak of the second wave of 2009 H1N1, HAI seroprevalence results suggest that 21% of persons in the Pittsburgh area had become infected and developed immunity. Extrapolating to the entire US population, we estimate that at least 63 million persons became infected in 2009. As was observed among clinical cases, this sero-epidemiological study revealed highest infection rates among school-age children. © 2010 Zimmer et al

Measurement of the B+ and B-0 lifetimes and search for CP(T) violation using reconstructed secondary vertices

The lifetimes of the B+ and B-0 mesons, and their ratio, have been measured in the OPAL experiment using 2.4 million hadronic Z(0) decays recorded at LEP. Z(0) --> b (b) over bar decays were tagged using displaced secondary vertices and high momentum electrons and muons. The lifetimes were then measured using well-reconstructed charged and neutral secondary vertices selected in this tagged data sample. The results aretau(B+) = 1.643 +/- 0.037 +/- 0.025 pstau(Bo) = 1.523 +/- 0.057 +/- 0.053 pstau(B+)/tau(Bo) = 1.079 +/- 0.064 +/- 0.041,where in each case the first error is statistical and the second systematic.A larger data sample of 3.1 million hadronic Z(o) decays has been used to search for CP and CPT violating effects by comparison of inclusive b and (b) over bar hadron decays, No evidence fur such effects is seen. The CP violation parameter Re(epsilon(B)) is measured to be Re(epsilon(B)) = 0.001 +/- 0.014 +/- 0.003and the fractional difference between b and (b) over bar hadron lifetimes is measured to(Delta tau/tau)(b) = tau(b hadron) - tau((b) over bar hadron)/tau(average) = -0.001 +/- 0.012 +/- 0.008