JT9D engine diagnostics. Task 2: Feasibility study of measuring in-service flight loads

The feasibility of measuring JT9D propulsion system flight inertia loads on a 747 airplane is studied. Flight loads background is discussed including the current status of 747/JT9D loads knowledge. An instrumentation and test plan is formulated for an airline-owned in-service airplane and the Boeing-owned RA001 test airplane. Technical and cost comparisons are made between these two options. An overall technical feasibility evaluation is made and a cost summary presented. Conclusions and recommendations are presented in regard to using existing inertia loads data versus conducting a flight test to measure inertia loads

Verwirklichung einer vollkommenen Glücksmöglichkeit/A perfect bliss-potential realized: “Wunsch, Indianer zu werden” im Lichte des Dao Kafkas übersetzend gelesen/Transreading “Wish, to Become Indian” in light of Kafka’s Dao

Walking an unexplored path, Huiwen Helen Zhang contextualizes Kafka's pithy and cryptic parable, “Wish, to Become Indian” in his transplantation of Daoist philosophy—an astonishing cross-cultural enigma that Zhang terms “Kafka's Dao”—and parses it through a micro-level approach that Zhang terms “transreading.” Contextualizing “Wish, to Become Indian” in Kafka's dialogue with ancient Chinese philosophers such as Laozi, Liezi, and Zhuangzi enables the reader to comprehend a series of otherwise incomprehensible puzzles. Zhang's scrutiny of Kafka's Dao shows how, through creative writing, Kafka not only penetrates esoteric Daoist classics, but also furthers their spirit in a way that transcends Richard Wilhelm, the pioneer European Sinologist. Transreading “Wish, to Become Indian” illuminates nuances that otherwise might have been overlooked. Wordplay, punctuational oddity, syntactic complexity, lyric density, and the curiously interlaced tenses and cases are all part of the idiosyncratic delivery of Kafka's message. Integrating the four activities of transreading—lento reading demanded and enhanced by cultural hermeneutics, creative writing required and inspired by poetic translation—unravels Kafka's riddle as a historical-cultural phenomenon.publishedVersio

Accretion and activity on the post-common-envelope binary RR~Cae

Current scenarios for the evolution of interacting close binaries - such as cataclysmic variables (CVs) - rely mainly on our understanding of low-mass star angular momentum loss (AML) mechanisms. The coupling of stellar wind with its magnetic field, i.e., magnetic braking, is the most promising mechanism to drive AML in these stars. There are basically two properties driving magnetic braking: the stellar magnetic field and the stellar wind. Understanding the mechanisms that drive AML therefore requires a comprehensive understanding of these two properties. RRCae is a well-known nearby (d=20pc) eclipsing DA+M binary with an orbital period of P=7.29h. The system harbors a metal-rich cool white dwarf (WD) and a highly active M-dwarf locked in synchronous rotation. The metallicity of the WD suggests that wind accretion is taking place, which provides a good opportunity to obtain the mass-loss rate of the M-dwarf component. We analyzed multi-epoch time-resolved high-resolution spectra of RRCae in search for traces of magnetic activity and accretion. We selected a number of well-known activity indicators and studied their short and long-term behavior. Indirect-imaging tomographic techniques were also applied to provide the surface brightness distribution of the magnetically active M-dwarf, and reveals a polar feature similar to those observed in fast-rotating solar-type stars. The blue part of the spectrum was modeled using a atmosphere model to constrain the WD properties and its metal enrichment. The latter was used to improve the determination of the mass-accretion rate from the M-dwarf wind. The presence of metals in the WD spectrum suggests that this component arises from accretion of the M-dwarf wind. A model fit to the WD gives Teff=(7260+/-250)K and logg=(7.8+/-0.1) dex with a metallicity of =(-2.8+/-0.1)dex, and a mass-accretion rate of dotMacc=(7+/-2)x1e-16Msun/yr.Comment: 14 pages, 7 Figures, 6 Table

The Factory and The Beehive II. Activity and Rotation in Praesepe and the Hyades

Open clusters are collections of stars with a single, well-determined age, and can be used to investigate the connections between angular-momentum evolution and magnetic activity over a star's lifetime. We present the results of a comparative study of the relationship between stellar rotation and activity in two benchmark open clusters: Praesepe and the Hyades. As they have the same age and roughly solar metallicity, these clusters serve as an ideal laboratory for testing the agreement between theoretical and empirical rotation-activity relations at $\approx$600 Myr. We have compiled a sample of 720 spectra --- more than half of which are new observations --- for 516 high-confidence members of Praesepe; we have also obtained 139 new spectra for 130 high-confidence Hyads. We have collected rotation periods ($P_{rot}$) for 135 Praesepe members and 87 Hyads. To compare $H\alpha$ emission, an indicator of chromospheric activity, as a function of color, mass, and Rossby number $R_o$, we first calculate an expanded set of $\chi$ values, with which we can obtain the $H\alpha$ to bolometric luminosity ratio, $L_{H\alpha}/L_{bol}$, even when spectra are not flux-calibrated and/or stars lack reliable distances. Our $\chi$ values cover a broader range of stellar masses and colors (roughly equivalent to spectral types from K0 to M9), and exhibit better agreement between independent calculations, than existing values. We find no difference between the two clusters in their $H\alpha$ equivalent width or $L_{H\alpha}/L_{bol}$ distributions, and therefore take the merged $H\alpha$ and $P_{rot}$ data to be representative of 600-Myr-old stars. Our analysis shows that $H\alpha$ activity in these stars is saturated for $R_o\leq0.11^{+0.02}_{-0.03}$. Above that value activity declines as a power-law with slope $\beta=-0.73^{+0.16}_{-0.12}$, before dropping off rapidly at $R_o\approx0.4$...Comment: 17 pages, 15 figures, Accepted by Ap

CP Violation and Matter Effect in Long Baseline Neutrino Oscillation Experiments

We show simple methods how to separate pure CP violating effect from matter effect in long baseline neutrino oscillation experiments with three generations of neutrinos. We give compact formulae for neutrino oscillation probabilities assuming one of the three neutrino masses (presumably tau-neutrino mass) to be much larger than the other masses and the effective mass due to matter effect. Two methods are shown: One is to observe envelopes of the curves of oscillation probabilities as functions of neutrino energy; a merit of this method is that only a single detector is enough to determine the presence of CP violation. The other is to compare experiments with at least two different baseline lengths; this has a merit that it needs only narrow energy range of oscillation data.Comment: 17 pages + 9 eps figures, LaTeX, errors are correcte