Cooling of rocket thrust chambers with liquid oxygen

Rocket engines using high pressure liquid oxygen (LOX) and kerosene (RP-1) as the propellants have been considered for future launch vehicle propulsion. Generally, in regeneratively cooled engines, the fuel is used to cool the combustion chamber. However, hydrocarbons such as RP-1 are limited in their cooling capability at high temperatures and pressures. Therefore, LOX is being considered as an alternative coolant. However, there has been concern as to the effect on the integrity of the chamber liner if oxygen leaks into the combustion zone through fatigue cracks that may develop between the cooling passages and the hot-gas side wall. To address this concern, an investigation was previously conducted with simulated fatigue cracks upstream of the thrust chamber throat. When these chambers were tested, an unexpected melting in the throat region developed which was not in line with the simulated fatigue cracks. The current experimental program was conducted in order to determine the cause for the failure in the earlier thrust chambers and to further investigate the effects of cracks in the thrust chamber liner upstream of the throat. The thrust chambers were tested at oxygen-to-fuel mixture ratios from 1.5 to 2.86 at a nominal chamber pressure of 8.6 MPa. As a result of the test series, the reason for the failure occurring in the earlier work was determined to be injector anomalies. The LOX leaking through the simulated fatigue cracks did not affect the integrity of the chambers

Framing hate: Moral foundations, party cues, and (In)tolerance of offensive speech

© 2017, PsychOpen. All rights reserved. One of the most controversial elements of political tolerance concerns support for hate speech. We argue that there are two factors that can reduce tolerance for hate speech: 1) moral foundations and 2) party cues. U.S. citizens’ tolerance of hate speech will be reduced when it is framed as a violation of a specific moral foundation, opposed by a political party, or when the morality violation is utilized by party elites. Using two survey experiments, we manipulated the target of hate speech (i.e. Muslims or the American flag), whether the speech violated a moral foundation (i.e. harm or loyalty), and which political party supported or opposed the hate speech in question. For flag burning, moral frames and party cues on their own reduced U.S. citizens’ tolerance relative to a non-political control, while moral frames and party cues were successful in reducing tolerance of anti-Muslim speech compared to a free speech appeal. Partisans were generally responsive to cues from the in-party. We also found instances of moral repackaging, where morally incongruent appeals from the in-party reduced tolerance of flag burning among Democrats. Among Republicans, harm morality decreased tolerance of anti-Muslim speech when invoked by the in-party, but increased tolerance when used by the out-party – an indication of the power of party cues to repackage moral arguments and to trigger backlash. These results provide a better understanding of what factors can affect tolerance for hate speech, providing political leaders and social justice advocates with a roadmap to alleviate this problem

The New Eclipsing Cataclysmic Variable SDSS 154453+2553

The cataclysmic variable SDSS154453+2553 was recently identified in the Sloan Digital Sky Survey. We obtained spectra and photometry at the MDM Observatory, which revealed an eclipse with a 6.03 hour period. The H{\alpha} emission line exhibits a strong rotational disturbance during eclipse, indicating that it arises in an accretion disk. A contribution from an M-type companion is also observed. Time-series photometry during eclipse gives an ephemeris of 2454878.0062(15) + 0.251282(2)E. We present spectroscopy through the orbit and eclipse photometry. Our analysis of the secondary star indicates a distance of 800 {\pm} 180 pc.Comment: 6 pages, 3 figures, Accepted for publication in PAS

Junior Recital: Julie Armstrong, Clarinet; Roberta Stimac, Piano; May 1, 1977

Centennial East Recital HallSunday EveningMay 1, 19777:00 p.m

Metabolomics in psoriatic disease: pilot study reveals metabolite differences in psoriasis and psoriatic arthritis.

ImportanceWhile "omics" studies have advanced our understanding of inflammatory skin diseases, metabolomics is mostly an unexplored field in dermatology.ObjectiveWe sought to elucidate the pathogenesis of psoriatic diseases by determining the differences in metabolomic profiles among psoriasis patients with or without psoriatic arthritis and healthy controls.DesignWe employed a global metabolomics approach to compare circulating metabolites from patients with psoriasis, psoriasis and psoriatic arthritis, and healthy controls.SettingStudy participants were recruited from the general community and from the Psoriasis Clinic at the University of California Davis in United States.ParticipantsWe examined metabolomic profiles using blood serum samples from 30 patients age and gender matched into three groups: 10 patients with psoriasis, 10 patients with psoriasis and psoriatic arthritis and 10 control participants. Main outcome(s) and measures(s): Metabolite levels were measured calculating the mean peak intensities from gas chromatography time-of-flight mass spectrometry.ResultsMultivariate analyses of metabolomics profiles revealed altered serum metabolites among the study population. Compared to control patients, psoriasis patients had a higher level of alpha ketoglutaric acid (Pso: 288 ± 88;Control209 ± 69; p=0.03), a lower level of asparagine (Pso: 5460 ± 980;Control7260 ± 2100; p=0.02), and a lower level of glutamine (Pso: 86000 ± 20000;Control111000 ± 27000; p=0.02). Compared to control patients, patients with psoriasis and psoriatic arthritis had increased levels of glucuronic acid (Pso + PsA: 638 ± 250;Control347 ± 61; p=0.001). Compared to patients with psoriasis alone, patients with both psoriasis and psoriatic arthritis had a decreased level of alpha ketoglutaric acid (Pso + PsA: 186 ± 80; Pso: 288 ± 88; p=0.02) and an increased level of lignoceric acid (Pso + PsA: 442 ± 280; Pso: 214 ± 64; p=0.02).Conclusions and relevanceThe metabolite differences help elucidate the pathogenesis of psoriasis and psoriatic arthritis and they may provide insights for therapeutic development

Trace element metabolism in human pregnancy.

The aims of this study were: i. to investigate the dietary intake of the essential trace elements, zinc and copper during pregnancy, ii. to assess the possible effects of these intakes on the outcome of pregnancy. iii. to study the absorption and retention of zinc, copper and manganese in normal primigravidae and those at risk of delivering small, light infants. Intakes of zinc and copper were calculated from weighed dietary surveys using food composition tables and the validity of these tables to calculate dietary nitrogen, zinc and copper was assessed by comparing analysed and calculated values. To investigate the effect of pregnancy on the absorption and retention of zinc, copper and manganese, metabolic balance studies were conducted on pregnant and non-pregnant women. Dietary intakes of zinc were less than the recommended level (U.S. Nat. Acad. Sci 1980). Zinc intake correlated with protein intake. Dietary copper intakes were lower than levels previously reported and less than the 'safe and adequate intake' (U.S. Nat. Acad. Sci. 1980). Dietary intakes of zinc and copper were not significantly different between a group of women who delivered small, light infants and those who delivered normal healthy infants. These recent findings suggest the U.S. Nat. Acad. Sci. recommended dietary intake for zinc during pregnancy maybe over estimated and therefore require reviewal and reassessment. Zinc and copper were retained in normal primigravidae during the third trimester; this may be related to the concomitant increase in fetal and maternal weight. Zinc and copper balance were negative in the primigravidae at risk of delivering small, light infants. This requires further investigation. Net intestinal losses of manganese was apparent in all groups of pregnant women

Learned communicative non-use is a reality in very early aphasia recovery: Preliminary results from an ongoing observational study.

Recent neurorehabilitation literature in animal motor models suggests very early (before day five post-stroke) intensive (over 300 repetitions) leads to histological damage (Krakauer et al, 2012) and late rehabilitation (commenced after day 30 post-stroke) is much less effective than intervention started earlier in recovery. The intricacies of directly applying animal models of stroke recovery and rehabilitation to human language have been well documented (Varley, 2011). In humans, the first 90 days post-stroke however, are believed to be the "window of opportunity” (Meyer et al., 2010) for neuronal changes to occur as part of neuroplasticity. Research investigating human stroke recovery models, indicates that the timing of commencement of therapy combined with therapy intensity are likely to be pivotal elements in overall stroke recovery (Kerr et al, 2011). Therapy intensity to facilitate stroke recovery in humans is noted to be far less than that in animal models (Krakauer at al., 2012). Research investigating overall activity levels in stroke survivors in the acute recovery demonstrated that patients spent only 13% of their time engaged in activity and spent 60% of the time alone (Berhardt et al, 2004). Further research showed that task specific movement practice occurred in only 51% of sessions during acute and sub-acute therapy sessions (Lang et al., 2009). Similarly, aphasia research in early stroke recovery demonstrated that on average stroke survivors received between 14 minutes (Godecke et al, 2011) and 1.3 hours (Bowen et al, 2012) of therapy per week during the first month post-stroke. To better understand the interactions that occur in early stroke recovery, this study focused on observed communicative activities that may underlie the neuroplasticity principles of “use it or lose it”, and “learned non-use” (Kleim 2011)

Developing Alphabetic Knowledge in a School-to-Home Project with Students Who Are At-Risk: Literature Review

Literacy skills are developing in children from the time they are born and should be nurtured during the preschool years (Joint Position Statement, 2005). There are important literacy skill sets for children to acquire to be competent readers. The 2009 National Early Literacy Panel has defined one of these skills as alphabetic knowledge (Bell & Westberg, 2009). Alphabetic knowledge is being able to recognize and name letters and their sounds. The research shows that mastery of alphabetic skills is required before children can engage successfully in phonemic awareness. (Bara, Gentaz & Cole, 2007). Parents can facilitate their child’s mastery of these skills through activities that can be integrated into play and their child’s daily schedule. Educators can provide resources and support for learning these skills through a school-to-home connection. This is invaluable to students who may be at-risk because of disabilities, being an English Language Learner, or living in a low-literacy or poverty home. This project provides a literature review of emergent literacy skills and the need for support of at-risk students. It also includes a resource book of activities that can be sent home for students to work on with their families

Developing Alphabetic Knowledge in a School-to-Home Project with Students Who Are At-Risk: Alphabetic Knowledge Activities Handbook

Early childhood educators are on the frontline of developing emergent literacy skills in their students. Research is abundant and clear about the importance of exposure to and experience with literacy activities for young children (Joint Position Statement- International Reading Association and the National Association for the Education of Young Children, 2005). However, students arrive in the classroom with varying skills and backgrounds relative to literacy, and many students are in a position to be considered at-risk of school failure. Teaching this population of students can be a challenge. This Alphabetic Knowledge Activities handbook was created to be a resource for educators to better meet the needs of all young students, yet targets those students who may be at-risk and in need of more support. The activities are intended to be used as a school-to-home program, to ensure that educators are collaborating with families as a teaching team. The activities, combined with a comprehensive literature review of research about at-risk children and the benefits of school-to-home collaborations, are meant to be used as a tool for all early childhood educators working with 3-5 year olds