Heat transfer results and operational characteristics of the NASA Lewis Research Center Hot Section Cascade Test Facility

The NASA Lewis Research Center gas turbine hot section test facility has been developed to provide a real-engine environment with well known boundary conditions for the aerothermal performance evaluation/verification of computer design codes. The initial aerothermal research data obtained are presented and the operational characteristics of the facility are discussed. This facility is capable of testing at temperatures and pressures up to 1600 K and 18 atm which corresponds to a vane exit Reynolds number range of 0.5x10(6) to 2.5x10(6) based on vane chord. The component cooling air temperature can be independently modulated between 330 and 700 K providing gas-to-coolant temperature ratios similar to current engine application. Research instrumentation of the test components provide conventional pressure and temperature measurements as well as metal temperatures measured by IR-photography. The primary data acquisition mode is steady state through a 704 channel multiplexer/digitizer. The test facility was configured as an annular cascade of full coverage filmcooled vanes for the initial series of research tests

Lactate-protechypoglycemia (LPH)

Here, we provide an overview of the concept of a lactate-protected hypoglycemia ( LPH ), originally proposed as lowering glucose while simultaneously increasing lactate concentration as a method by which tumors might be targeted. Central to this hypothesis is that lactate can act as a critical salvage fuel for the central nervous system, allowing for wide perturbations in whole body and central nervous system glucose concentrations. Further, many tumors exhibit the Warburg effect, consuming glucose and producing and exporting lactate despite adequate oxygenation. While some recent data have provided evidence for a reverse-Warburg, where some tumors may preferentially consume lactate, many of these experimental methods rely on a significant elevation in lactate in the tumor microenvironment. To date it remains unclear how various tumors behav

Lactate-Protected Hypoglycemia (LPH)

Here, we provide an overview of the concept of a lactate-protected hypoglycemia ("LPH"), originally proposed as lowering glucose while simultaneously increasing lactate concentration as a method by which tumors might be targeted. Central to this hypothesis is that lactate can act as a critical salvage fuel for the central nervous system, allowing for wide perturbations in whole body and central nervous system glucose concentrations. Further, many tumors exhibit "the Warburg" effect, consuming glucose and producing and exporting lactate despite adequate oxygenation. While some recent data have provided evidence for a "reverse-Warburg," where some tumors may preferentially consume lactate, many of these experimental methods rely on a significant elevation in lactate in the tumor microenvironment. To date it remains unclear how various tumors behavein vivo, and how they might respond to perturbations in lactate and glucose concentrations or transport inhibition. By exploiting and targeting lactate transport and metabolism in tumors (with a combination of changes in lactate and glucose concentrations, transport inhibitors, etc.), we can begin developing novel methods for targeting otherwise difficult to treat pathologies in the brain and spinal cord. Here we discuss evidence both experimental and observational, and provide direction for next steps in developing therapies based on these concepts

Effects of surface modifications on molecular diffusion in mesoporous catalytic materials

In this work, we use pulsed-field gradient (PFG) NMR to probe molecular diffusion of liquids inside mesoporous structures and assess the influence of surface modifications, namely, deposition of palladium (Pd) nanoparticles over alumina (Al2O3) surfaces and passivation of titania (TiO2) surfaces with alkyl chains, on the diffusion pattern

Educational Technology: Availability and Use in Chicago's Public Schools

With expectations for technology use and its potential costs continuing to rise, the Consortium on Chicago School Research sought to provide baseline information on educational technology -- the use of computers and the Internet for instructional purposes -- in Chicago public schools. We addressed three questions in a year-long study that included both quantitative and qualitative analyses: (1) What are the current levels of technology availability and use? (2) Are availability and use distributed equitably across students, teachers, and schools in the district? and (3) What essential organizational supports are necessary to encourage technology use in schools? We examine these topics by looking at nearly 100,000 responses to the Consortium's biannual survey of teachers and students in 434 of Chicago's schools, in addition to other administrative data. Further insight was gained through site visits to schools with model technology programs.This study was sponsored in part by the Chicago Urban League

Analysis of developing laminar flows in circular pipes using a higher-order finite-difference technique

A higher-order finite-difference technique is developed to calculate the developing-flow field of steady incompressible laminar flows in the entrance regions of circular pipes. Navier-Stokes equations governing the motion of such a flow field are solved by using this new finite-difference scheme. This new technique can increase the accuracy of the finite-difference approximation, while also providing the option of using unevenly spaced clustered nodes for computation such that relatively fine grids can be adopted for regions with large velocity gradients. The velocity profile at the entrance of the pipe is assumed to be uniform for the computation. The velocity distribution and the surface pressure drop of the developing flow then are calculated and compared to existing experimental measurements reported in the literature. Computational results obtained are found to be in good agreement with existing experimental correlations and therefore, the reliability of the new technique has been successfully tested

Mars Relay Lander and Orbiter Overflight Profile Estimation

This software allows science and mission operations to view graphs of geometric overflights of satellites and landers within the Mars (or other planetary) networks. It improves on the MaROS Web interface within any modern Web browser, in that it adds new capabilities to the MaROS suite. The profile for an overflight is an important element for selecting communication/ overflight opportunities between the landers and orbiters within the Mars network. Unfortunately, determining these estimates is very computationally expensive and difficult to compute by hand. This software allows the user to select different overflights (via the existing MaROS Web interface) and specify the smoothness of the estimation. Estimates for the geometric relationship between a lander and an orbiter are determined based upon the orbital conditions of the orbiter at the moment the orbiter rises above the horizon from the perspective of the lander. It utilizes 2-body orbital equations to propagate the trajectory through the duration of the view period, and returns profiles that represent the range between the two vehicles, and the elevation and azimuth angles of the orbiter as measured from the lander s position. The algorithms assume a 2-body relationship with an ideal, spherical planetary body, so therefore can see errors less than 2% at polar landing sites on Mars. These algorithms are being implemented to provide rough estimates rapidly for the geometry of a geometric view period where more complete data is unavailable, such as for planning purposes. While other software for this task exists, each at the time of this reporting has been contained within a much more complicated package. This tool allows science and mission operations to view the estimates with a few clicks of the mouse

Bioconversion of cellulose into bisabolene using Ruminococcus flavefaciens and Rhodosporidium toruloides

In this study, organic acids were demonstrated as a promising carbon source for bisabolene production by the non-conventional yeast, Rhodosporidium toruloides, at microscale with a maximum titre of 1055 ± 7 mg/L. A 125-fold scale-up of the optimal process, enhanced bisabolene titres 2.5-fold to 2606 mg/L. Implementation of a pH controlled organic acid feeding strategy at this scale lead to a further threefold improvement in bisabolene titre to 7758 mg/L, the highest reported microbial titre. Finally, a proof-of-concept sequential bioreactor approach was investigated. Firstly, the cellulolytic bacterium Ruminococcus flavefaciens was employed to ferment cellulose, yielding 4.2 g/L of organic acids. R. toruloides was subsequently cultivated in the resulting supernatant, producing 318 ± 22 mg/L of bisabolene. This highlights the feasibility of a sequential bioprocess for the bioconversion of cellulose, into biojet fuel candidates. Future work will focus on enhancing organic acid yields and the use of real lignocellulosic feedstocks to further enhance bisabolene production

MAGNETIC RESONANCE (MR) MEASUREMENTS OF THE MASS FLUX IN GAS-SOLID FLUIDIZED BEDS

Magnetic Resonance (MR) Imaging was used to measure the time-averaged voidage and particle velocity in a 3D gas-solid fluidized bed. Two different distributors were used. The mass-flux through a horizontal plane was calculated by combining the local voidage and particle velocity measurements. Based on the conservation of mass it was possible to give an error in the combined voidage and particle velocity measurements. It was found that the error in the mass flux was usually small (\u3c 5%), albeit increasing with increasing fluidization velocities