Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 7: High pressure fuel turbo-pump third stage impeller analysis

This volume summarizes the analysis used to assess the structural life of the Space Shuttle Main Engine (SSME) High Pressure Fuel Turbo-Pump (HPFTP) Third Stage Impeller. This analysis was performed in three phases, all using the DIAL finite element code. The first phase was a static stress analysis to determine the mean (non-varying) stress and static margin of safety for the part. The loads involved were steady state pressure and centrifugal force due to spinning. The second phase of the analysis was a modal survey to determine the vibrational modes and natural frequencies of the impeller. The third phase was a dynamic response analysis to determine the alternating component of the stress due to time varying pressure impulses at the outlet (diffuser) side of the impeller. The results of the three phases of the analysis show that the Third Stage Impeller operates very near the upper limits of its capability at full power level (FPL) loading. The static loading alone creates stresses in some areas of the shroud which exceed the yield point of the material. Additional cyclic loading due to the dynamic force could lead to a significant reduction in the life of this part. The cyclic stresses determined in the dynamic response phase of this study are based on an assumption regarding the magnitude of the forcing function

Factors Involved in Immune Modulation of Bovine Leukemia Virus Infection.

Bovine Leukemia Virus (BLV) is an exogenous type-C retrovirus which can induce an aleukemic (AL) stage, a persistent lymphocytotic (PL) stage, or a lymphosarcomatous (LS) stage in infected animals. After experimental infection with BLV, whole blood and serum samples were obtained from 12 holstein heifers for 103 weeks and used to correlate clinical signs (visual observation and white blood cell counts) with changes in humoral immune response (Agar gel immunodiffusion using envelope gp50 as primary antigen, and ELISA and Western immunoblots using whole BLV as antigen). Monoclonal antibodies against BLV envelope gp50 and gag p24 were produced to confirm reactivity to specific proteins for the various assays. To confirm reactivity of monoclonals and produce large amounts of selected proteins for later studies of BLV, the genes for env, gag, and pX were cloned into eucaryotic expression vectors. After transfection of appropriate plasmids, correct expression of cloned genes was confirmed using monoclonals and indirect immunofluorescence for gp50 and p24 and CAT assay for px. Total lymphocyte counts indicated 6 cattle reached the PL stage during the 103 weeks post infection (PI). Cows progressed through three transient disease stages in the first 3 months PI: transient eosinophilia, lymph node enlargement and lymphocytosis. Of the 6 cattle demonstrating early transient lymph node enlargement, 5/6 were AL. Changes in the humoral immune response to BLV were best detected using Western immunoassays. AL cattle were more likely to have an increased antibody response to the gag protein p24 early PI as compared to PL cattle. PL animals usually reached their highest p24 antibody responses after conversion to the PL stage. Antibody response to env gp50 increased as a function of time PI regardless of disease stage. PL cattle tended to recognize a greater number of the lesser gag proteins, p15, p12 and p10 in the first year PI than AL cattle. All cattle decreased markedly in their reactivity to any of these lesser proteins after 51 weeks PI

Trajectories of university adjustment in the United Kingdom: Emotion management and emotional self-efficacy protect against initial poor adjustment

Little is known about individual differences in the pattern of university adjustment. This study explored longitudinal associations between emotional self-efficacy, emotion management, university adjustment, and academic achievement in a sample of first year undergraduates in the United Kingdom (N=331). Students completed measures of adjustment to university at three points during their first year at university. Latent Growth Mixture Modeling identified four trajectories of adjustment: (1) low, stable adjustment, (2) medium, stable adjustment, (3) high, stable adjustment, and (4) low, increasing adjustment. Membership of the low, stable adjustment group was predicted by low emotional self-efficacy and low emotion management scores, measured at entry into university. This group also had increased odds of poor academic achievement, even when grade at entry to university was controlled. Students who increased in adjustment had high levels of emotion management and emotional self-efficacy, which helped adaptation. These findings have implications for intervention

Altered three-dimensional trunk and hip kinetics and loss of variability during gait in chronic low back pain individuals

Trabalho apresentado em 10th Interdisciplinary World Congress on Low Back & Pelvic Girdle Pain, 28-31 de outubro 2019, Antuérpia, BélgicaN/

Test-retest reliability and minimal detectable change of three-dimensional gait analysis in chronic low back pain patients and healthy individuals

Trabalho apresentado no IFOMPT 2016 - World Congress of Manual and Musculoskeletal Physiotherapy, 4-8 julho de 2016, Glasgow, Escóciainfo:eu-repo/semantics/publishedVersio

The in vitro effects of artificial and natural sweeteners on the immune system using whole blood culture assays

This article investigates the effects of commercially available artificial (aspartame, saccharin, sucralose) and natural sweeteners (brown sugar, white sugar, molasses) on the immune system. Human whole blood cultures were incubated with various sweeteners and stimulated in vitro with either phytohemagglutinin or endotoxin. Harvested supernatants were screened for cytotoxicity and cytokine release. Results showed that none of the artificial or natural sweeteners proved to be cytotoxic, indicating that no cell death was induced in vitro. The natural sweetener, sugar cane molasses (10 ug=mL), enhanced levels of the inflammatory biomarker IL-6 while all artificial sweeteners (10 ug=mL) revealed a suppressive effect on IL-6 secretion (P<0.001). Exposure of blood cells to sucralose-containing sweeteners under stimulatory conditions reduced levels of the biomarker of humoral immunity, Interleukin-10 (P<0.001). The cumulative suppression of Interleukin-6 and Interleukin-10 levels induced by sucralose may contribute to the inability in mounting an effective humoral response when posed with an exogenous threat.Web of Scienc

Mixed Weyl Symbol Calculus and Spectral Line Shape Theory

A new and computationally viable full quantum version of line shape theory is obtained in terms of a mixed Weyl symbol calculus. The basic ingredient in the collision--broadened line shape theory is the time dependent dipole autocorrelation function of the radiator-perturber system. The observed spectral intensity is the Fourier transform of this correlation function. A modified form of the Wigner--Weyl isomorphism between quantum operators and phase space functions (Weyl symbols) is introduced in order to describe the quantum structure of this system. This modification uses a partial Wigner transform in which the radiator-perturber relative motion degrees of freedom are transformed into a phase space dependence, while operators associated with the internal molecular degrees of freedom are kept in their original Hilbert space form. The result of this partial Wigner transform is called a mixed Weyl symbol. The star product, Moyal bracket and asymptotic expansions native to the mixed Weyl symbol calculus are determined. The correlation function is represented as the phase space integral of the product of two mixed symbols: one corresponding to the initial configuration of the system, the other being its time evolving dynamical value. There are, in this approach, two semiclassical expansions -- one associated with the perturber scattering process, the other with the mixed symbol star product. These approximations are used in combination to obtain representations of the autocorrelation that are sufficiently simple to allow numerical calculation. The leading O(\hbar^0) approximation recovers the standard classical path approximation for line shapes. The higher order O(\hbar^1) corrections arise from the noncommutative nature of the star product.Comment: 26 pages, LaTeX 2.09, 1 eps figure, submitted to 'J. Phys. B.

Creating evidence towards making statements about classroom activity

In this paper I examine some of the issues underlying the creation of data in classroom based research. In particular, I focus on the status of evidence offered by a researcher describing children’s activity in order to demonstrate how the researcher’s interest necessarily conditions the various stages of any enquiry. I show how evidence is created through a process of selection and interpretation consequential to the researcher making assumptions about the situation he or she observes. I also show how the descriptions themselves, as offered by the researcher, become a material part of the situation being described. In the first section I consider the issues arising in the identifying and gaining access to lessons. This is followed by a discussion about the generation of data. Finally, I examine some of the difficulties to be faced in interpreting such data

End-of-life care across Southern Europe: A critical review of cultural similarities and differences between Italy, Spain and Portugal

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Transition to adult care of young people with congenital heart disease: Impact of a service on knowledge and self-care skills, and correlates of a successful transition

Aims Less than one-third of adolescents with congenital heart disease (CHD) successfully transition to adult care, missing out on education of their cardiac condition, and risking loss to follow-up. We assessed the efficacy of our transition clinic on patient education and empowerment and identified correlates of successful transition. Methods and results Overall, 592 patients were seen at least once in our transition service between 2015 and 2022 (age 15.2 ± 1.8 years, 47.5% female). Most adolescents (53%) had moderate CHD, followed by simple (27.9%) and severe (19.1%) CHD. Learning disability (LD) was present in 18.9% and physical disability (PD) in 4.7%. In patients without LD, knowledge of their cardiac condition improved significantly from the first to the second visit (naming their condition: from 20 to 52.3%, P 0.05). Treatment adherence and management involvement, self-reported anxiety, and dental care awareness did not change over time. Successful transition (attendance of ≥ 2 clinics) was achieved in 49.3%. Younger age at the first visit, simpler CHD, and absence of PD were associated with successful transition. Conclusion A transition service positively impacts on patient education and empowerment in most CHD adolescents transitioning to adult care. Strategies to promote a tailored support for patients with LD should be sought, and earlier engagement should be encouraged to minimize follow-up losses