Modal survey of the space shuttle solid rocket motor using multiple input methods

The ability to accurately characterize propellant in a finite element model is a concern of engineers tasked with studying the dynamic response of the Space Shuttle Solid Rocket Motor (SRM). THe uncertainties arising from propellant characterization through specimem testing led to the decision to perform a model survey and model correlation of a single segment of the Shuttle SRM. Multiple input methods were used to excite and define case/propellant modes of both an inert segment and, later, a live propellant segment. These tests were successful at defining highly damped, flexible modes, several pairs of which occured with frequency spacing of less than two percent

Size Dependence in Non-sperm Ejaculate Production is Reflected in Daily Energy Expenditure and Resting Metabolic Rate

The non-sperm components of an ejaculate, such as copulatory plugs, can be essential to male reproductive success. But the costs of these ejaculate components are often considered trivial. In polyandrous species, males are predicted to increase energy allocation to the production of non-sperm components, but this allocation is often condition dependent and the energetic costs of their production have never been quantified. Red-sided garter snakes (Thamnophis sirtalis parietalis) are an excellent model with which to quantify the energetic costs of non-sperm components of the ejaculate as they exhibit a dissociated reproductive pattern in which sperm production is temporally disjunct from copulatory plug production, mating and plug deposition. We estimated the daily energy expenditure and resting metabolic rate of males after courtship and mating, and used bomb calorimetry to estimate the energy content of copulatory plugs. We found that both daily energy expenditure and resting metabolic rate were significantly higher in small mating males than in courting males, and a single copulatory plug without sperm constitutes 5–18% of daily energy expenditure. To our knowledge, this is the first study to quantify the energetic expense of size-dependent ejaculate strategies in any species

Expression of RUNX1 correlates with poor patient prognosis in triple negative breast cancer

The RUNX1 transcription factor is widely recognised for its tumour suppressor effects in leukaemia. Recently a putative link to breast cancer has started to emerge, however the function of RUNX1 in breast cancer is still unknown. To investigate if RUNX1 expression was important to clinical outcome in primary breast tumours a tissue microarray (TMA) containing biopsies from 483 patients with primary operable invasive ductal breast cancer was stained by immunohistochemistry. RUNX1 was associated with progesterone receptor (PR)-positive tumours (P<0.05), more tumour CD4+(P<0.05) and CD8+(P<0.01) T-lymphocytic infiltrate, increased tumour CD138+plasma cell (P<0.01) and more CD68+macrophage infiltrate (P<0.001). RUNX1 expression did not influence outcome of oestrogen receptor (ER)-positive or HER2-positive disease, however on univariate analysis a high RUNX1 protein was significantly associated with poorer cancer-specific survival in patients with ER-negative (P<0.05) and with triple negative (TN) invasive breast cancer (P<0.05). Furthermore, multivariate Cox regression analysis of cancer-specific survival showed a trend towards significance in ER-negative patients (P<0.1) and was significant in triple negative patients (P<0.05). Of relevance, triple negative breast cancer currently lacks good biomarkers and patients with this subtype do not benefit from the option of targeted therapy unlike patients with ER-positive or HER2-positive disease. Using multivariate analysis RUNX1 was identified as an independent prognostic marker in the triple negative subgroup. Overall, our study identifies RUNX1 as a new prognostic indicator correlating with poor prognosis specifically in the triple negative subtype of human breast cancer

Hubble Space Telescope Astrometry of the Procyon System

The nearby star Procyon is a visual binary containing the F5 IV-V subgiant Procyon A, orbited in a 40.84 yr period by the faint DQZ white dwarf Procyon B. Using images obtained over two decades with the Hubble Space Telescope, and historical measurements back to the 19th century, we have determined precise orbital elements. Combined with measurements of the parallax and the motion of the A component, these elements yield dynamical masses of 1.478 +/- 0.012 Msun and 0.592 +/- 0.006 Msun for A and B, respectively. The mass of Procyon A agrees well with theoretical predictions based on asteroseismology and its temperature and luminosity. Use of a standard core-overshoot model agrees best for a surprisingly high amount of core overshoot. Under these modeling assumptions, Procyon A's age is ~2.7 Gyr. Procyon B's location in the H-R diagram is in excellent agreement with theoretical cooling tracks for white dwarfs of its dynamical mass. Its position in the mass-radius plane is also consistent with theory, assuming a carbon-oxygen core and a helium-dominated atmosphere. Its progenitor's mass was 1.9-2.2 Msun, depending on its amount of core overshoot. Several astrophysical puzzles remain. In the progenitor system, the stars at periastron were separated by only ~5 AU, which might have led to tidal interactions and even mass transfer; yet there is no direct evidence that these have occurred. Moreover the orbital eccentricity has remained high (~0.40). The mass of Procyon B is somewhat lower than anticipated from the initial-to-final-mass relation seen in open clusters. The presence of heavy elements in its atmosphere requires ongoing accretion, but the place of origin is uncertain.Comment: Accepted by Astrophysical Journa

The Thermoelectric Properties of Mixed Crystals of Mg GexSi _x

ABSTRACT The purpose of this work was to determine the thermoelectric properties of the pseudobinary system MgfSi-MgfGe. The compositions investigated were Mg2Si, Mg2Ge0.fSi0.s, MgaGe0.4Si0.6, Mg2Ge0.6Si0.4, Mg2Ge0.8Si0.2, and Mg2Ge. X-ray diffraction lattice parameter measurements and differential thermal analysis measurements established the existence of complete solid solubility between Mg~Si and Mg2Ge. Both the lattice parameter and liquidus temperature show almost linear variation with composition in this system. The melting temperature of MgfSi was found to be 1070" ___ 5"C, while that of MgfGe was found to be 1102" _ 5~ Electrical resistivity and Hall effect measurements indicated that at 300*K the electron Hall mobility in the mixed crystals is essentially the same as that of the pure compounds. Maximum values obtained were slightly above 300 cm2/volt sec. The forbidden energy gap appeared to vary monotonically from about 0.78 electronvolt (ev) for MgfSi to about 0.70 ev for MgfGe. Thermal conductivity measurements on the pseudobinary system showed that the lattice thermal conductivity of the solid solutions is substantially lower than that of either of the pure compounds at 300~ At this temperature the lattice thermal conductivity of Mg2Ge0.6Sio.4 was found to be 0.0268 watt/cm *K. The maximum thermoelectric figure of merit which could be obtained with these materials is not as good as that of other materials now in use. Lattice parameter determinations, differential thermal analysis measurements, and microscopic examinations at six different compositions in the system MgfGe-MgfSi showed that there was complete solid solubility between Mg2Si and MgfGe; thermal conductivity, Seebeck coefficient, electrical conductivity, and Hall effect were measured on these samples, and all data were analyzed to correlate the results with theory

Hungry for change: the Sydney Food Fairness Alliance

The Sydney Food Fairness Alliance is one of a growing number of nascent food movements in Australia to have emerged out of concern for the country’s food future, as well as the deleterious effect the present food system is having on its citizens’ health and the continent’s fragile environment. The Alliance’s structure and activities clearly position it as a new social movement (NSM) engaged in collective action on a specific issue, in this instance, food security/justice, and operating outside the political sphere while aiming to influence and affect societal change. Food security as a human right lies at the heart of the Alliance’s philosophy, and equitable, sustainable food policies for New South Wales are a core focus of its advocacy work. The authors argue that the Alliance is a distinctive food movement in that it positions itself as an \u27umbrella\u27 organization representing a wide range of stakeholders in the food system. This chapter reflects on the values, achievements, issues of concern, strengths and weaknesses, and future of the Sydney Food Fairness Alliance. This resource is Chapter 8 in \u27Food Security in Australia: Challenges and Prospects for the Future\u27 published by Springer in 2013

The phase diagram for the binary system indium-tellurium and electrical properties of In3Te5

The phase diagram for the binary system indium-tellurium has been clarified and corrected, particularly in the region near the composition In2Te3. This material is a potentially important semiconductor, either alone or in combination with other materials, such as Cu3Te, Ag2Te, CdTe, etc.Results of this study were obtained by correlating differential thermal analysis (DTA), chemical analyses of zone-refined ingots, microscopic analysis, and X-ray determinations.Two new phases have been identified, and the compositions of three other phases have been determined more precisely. (1) The phase In2Te (33.3 at. %Te) does not exist; the composition should be In9Te7 (43 at. %Te). The peritectic decomposition temperature is 462[deg]C. (2) The phase InTe (50.0 at. % Te) has the composition In30Te31 (50.8 at. % Te). The congruent melting point is 696[deg]C. (3) A new phase In3Te4 (57.0 at. % Te) has been found having a peritectic decomposition temperature of 650[deg]C. (4) The phase In2Te3 (60.0 at. % Te) has the composition In27Te40 (59.7 at.% Te). The congruent melting point is 667[deg]C, and there is a phase transition at about 550[deg]C. (5) A new phase In3Te5 (62.5 at. % Te) has been found, having a peritectic decomposition temperature of 625[deg]C, and a phase transition at 463[deg]C. (6) The phase In2Te5 (71.5 at. % Te) was prepared. (7) Electrical measurements on In3Te5 show a large conductivity increase associated with the phase transition at 463[deg]C. (8) Electrical measurements on zone refined In2Te3, were non-reproducible.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32121/1/0000172.pd

Bostonia: The Boston University Alumni Magazine. Volume 12

Founded in 1900, Bostonia magazine is Boston University’s main alumni publication