290 research outputs found
Description of a Pressure Measurement Technique for Obtaining Surface Static Pressures of a Radial Turbine
The aerodynamic performance of a solid uncooled version of a cooled radial turbine was evaluated in the Small Engine Components Test Facility Turbine rig at the NASA Lewis Research Center. Specifically, an experiment was conducted to rotor surface static pressures. This was the first time surface static pressures had been measured on a radial turbine at NASA Lewis. These pressures were measured by a modified Rotating Data Package (RDP), a standard product manufactured by Scanivalve, Inc. Described here are the RDP, and the modifications that were made, as well as the checkout, installation, and testing procedures. The data presented are compared to analytical results obtained from NASA's MERIDL TSONIC BLAYER (MTSB) code
Experimental Evaluation of a Cooled Radial-inflow Turbine
Two 14.4 inch tip diameter rotors were installed and tested in the Small Engines Component Turbine Facility (SECTF) at NASA Lewis Research Center. The rotors, a solid and a cooled version of a radial-inflow turbine, were tested with a 15 vane stat or over a set of rotational speeds ranging from 80 to 120 percent design speed (17,500 to 21,500 rpm). The total-to-total stage pressure ratios ranged from 2.5 to 5.5. The data obtained at the equivalent conditions using the solid version of the rotor are presented with the cooled rotor data. A Reynolds number of 381,000 was maintained for both rotors, whose stages had a design mass flow of 4.0 Ibm/sec, a design work level of 59.61 Btu/lbm, and a design efficiency of 87 percent. The results include mass flow data, turbine torque, turbine exit flow angles, stage efficiency, and rotor inlet and exit surveys
Market-Driven Innovation
A new method for starting the iterative innovation process from the market side based on a sociological trend has been developed. It eliminates the traditional difference between the innovators and the sociological group that carries this trend, which can only be achieved by combining real-world innovation with innovation education. The method for market need discovery is presented as a step-by-step process with detailed reasoning, followed by a real-world example that details the outcomes at every step along the way. The example concludes with a detailed description of the outcome after the first innovation iteration cycle. The richness of the resulting concept demonstrates that an innovation process can be successfully started from the market side via the proposed method
Surface Structure of Liquid Metals and the Effect of Capillary Waves: X-ray Studies on Liquid Indium
We report x-ray reflectivity (XR) and small angle off-specular diffuse
scattering (DS) measurements from the surface of liquid Indium close to its
melting point of C. From the XR measurements we extract the surface
structure factor convolved with fluctuations in the height of the liquid
surface. We present a model to describe DS that takes into account the surface
structure factor, thermally excited capillary waves and the experimental
resolution. The experimentally determined DS follows this model with no
adjustable parameters, allowing the surface structure factor to be deconvolved
from the thermally excited height fluctuations. The resulting local electron
density profile displays exponentially decaying surface induced layering
similar to that previously reported for Ga and Hg. We compare the details of
the local electron density profiles of liquid In, which is a nearly free
electron metal, and liquid Ga, which is considerably more covalent and shows
directional bonding in the melt. The oscillatory density profiles have
comparable amplitudes in both metals, but surface layering decays over a length
scale of \AA for In and \AA for Ga. Upon controlled
exposure to oxygen, no oxide monolayer is formed on the liquid In surface,
unlike the passivating film formed on liquid Gallium.Comment: 9 pages, 5 figures; submitted to Phys. Rev.
Measurement of the Coolant Channel Temperatures and Pressures of a Cooled Radial-Inflow Turbine
Instrumentation has been installed on the surface of a cooled radial-inflow turbine. Thermocouples and miniature integrated sensor pressure transducers were installed to measure steady state coolant temperatures, blade wall temperatures, and coolant pressures. These measurements will eventually be used to determine the heat transfer characteristics of the rotor. This paper will describe the procedures used to install and calibrate the instrumentation and the testing methods followed. A limited amount of data will compare the measured values to the predicted values
The influence of postgraduate qualifications on educational identity formation of healthcare professionals
Demand for postgraduate qualifications in medical education can be judged by the increase in providers worldwide over the last two decades. However, research into the impact of such courses on identity formation of healthcare professionals is limited. This study investigates the influence of such programmes on graduates’ educational identities, practices and career progression. Informed by constructivist grounded theory (CGT), semi-structured interviews were conducted with 27 graduates (2008–2012) from one postgraduate programme, who were at different stages in their careers worldwide. The audio data were transcribed and analysed using a CGT approach. Participants enrolled in award-bearing medical education courses for various intrinsic and extrinsic reasons. The findings from this study highlight their development as educators, and educational researchers, leaders and learners, as their self-efficacy in educational practices and engagement in scholarly activities increased. Graduates attributed career progression to the qualification, with many being promoted into senior positions. They also described substantial performance attainments in the workplace. The findings contribute to understanding the complexity and nuances of educational identity formation of healthcare professionals. A qualification in medical education encouraged transformational changes and epistemological development as an educator. Awareness of these findings will inform both those considering enrolment and those supporting them of potential benefits of these programmes
Atypical basic movement kinematics in autism spectrum conditions
Individuals with autism spectrum conditions have difficulties in understanding and responding appropriately to others. Additionally, they demonstrate impaired perception of biological motion and problems with motor control. Here we investigated whether individuals with autism move with an atypical kinematic profile, which might help to explain perceptual and motor impairments, and in principle may contribute to some of their higher level social problems. We recorded trajectory, velocity, acceleration and jerk while adult participants with autism and a matched control group conducted horizontal sinusoidal arm movements. Additionally, participants with autism took part in a biological motion perception task in which they classified observed movements as ‘natural’ or ‘unnatural’. Results show that individuals with autism moved with atypical kinematics; they did not minimize jerk to the same extent as the matched typical control group, and moved with greater acceleration and velocity. The degree to which kinematics were atypical was correlated with a bias towards perceiving biological motion as ‘unnatural’ and with the severity of autism symptoms as measured by the Autism Diagnostic Observation Schedule. We suggest that fundamental differences in movement kinematics in autism might help to explain their problems with motor control. Additionally, developmental experience of their own atypical kinematic profiles may lead to disrupted perception of others’ actions
Space Debris Mitigation and Remediation: Perspectives of Affordable Hybrid Propulsion Implementations
Basic science232. Certolizumab pegol prevents pro-inflammatory alterations in endothelial cell function
Background: Cardiovascular disease is a major comorbidity of rheumatoid arthritis (RA) and a leading cause of death. Chronic systemic inflammation involving tumour necrosis factor alpha (TNF) could contribute to endothelial activation and atherogenesis. A number of anti-TNF therapies are in current use for the treatment of RA, including certolizumab pegol (CZP), (Cimzia ®; UCB, Belgium). Anti-TNF therapy has been associated with reduced clinical cardiovascular disease risk and ameliorated vascular function in RA patients. However, the specific effects of TNF inhibitors on endothelial cell function are largely unknown. Our aim was to investigate the mechanisms underpinning CZP effects on TNF-activated human endothelial cells. Methods: Human aortic endothelial cells (HAoECs) were cultured in vitro and exposed to a) TNF alone, b) TNF plus CZP, or c) neither agent. Microarray analysis was used to examine the transcriptional profile of cells treated for 6 hrs and quantitative polymerase chain reaction (qPCR) analysed gene expression at 1, 3, 6 and 24 hrs. NF-κB localization and IκB degradation were investigated using immunocytochemistry, high content analysis and western blotting. Flow cytometry was conducted to detect microparticle release from HAoECs. Results: Transcriptional profiling revealed that while TNF alone had strong effects on endothelial gene expression, TNF and CZP in combination produced a global gene expression pattern similar to untreated control. The two most highly up-regulated genes in response to TNF treatment were adhesion molecules E-selectin and VCAM-1 (q 0.2 compared to control; p > 0.05 compared to TNF alone). The NF-κB pathway was confirmed as a downstream target of TNF-induced HAoEC activation, via nuclear translocation of NF-κB and degradation of IκB, effects which were abolished by treatment with CZP. In addition, flow cytometry detected an increased production of endothelial microparticles in TNF-activated HAoECs, which was prevented by treatment with CZP. Conclusions: We have found at a cellular level that a clinically available TNF inhibitor, CZP reduces the expression of adhesion molecule expression, and prevents TNF-induced activation of the NF-κB pathway. Furthermore, CZP prevents the production of microparticles by activated endothelial cells. This could be central to the prevention of inflammatory environments underlying these conditions and measurement of microparticles has potential as a novel prognostic marker for future cardiovascular events in this patient group. Disclosure statement: Y.A. received a research grant from UCB. I.B. received a research grant from UCB. S.H. received a research grant from UCB. All other authors have declared no conflicts of interes
The orphaning experience: descriptions from Ugandan youth who have lost parents to HIV/AIDS
The HIV/AIDS epidemic has continued to pose significant challenges to countries in Sub-Saharan Africa. Millions of African children and youth have lost parents to HIV/AIDS leaving a generation of orphans to be cared for within extended family systems and communities. The experiences of youth who have lost parents to the HIV/AIDS epidemic provide an important ingress into this complex, evolving, multi-dimensional phenomenon. A fundamental qualitative descriptive study was conducted to develop a culturally relevant and comprehensive description of the experiences of orphanhood from the perspectives of Ugandan youth. A purposeful sample of 13 youth who had lost one or both parents to HIV/AIDS and who were affiliated with a non-governmental organization providing support to orphans were interviewed. Youth orphaned by HIV/AIDS described the experience of orphanhood beginning with parental illness, not death. Several losses were associated with the death of a parent including lost social capitol, educational opportunities and monetary assets. Unique findings revealed that youth experienced culturally specific stigma and conflict which was distinctly related to their HIV/AIDS orphan status. Exploitation within extended cultural family systems was also reported. Results from this study suggest that there is a pressing need to identify and provide culturally appropriate services for these Ugandan youth prior to and after the loss of a parent(s)
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