The role of inclusions in the initiation and propagation of fatigue cracks in low allloy steels

Imperial Users onl

Insulation and Structural Support for Solar Electric Cooking

The Insulated Solar Electric Cooker (ISEC) project is aimed at providing an alternative method for cooking that does not require fuel or fire, has no harmful emissions and is appealing to the culinary tradition of cultures around the world. The World Health Organization estimates that three billion people cook with biomass and coal, which causes 4 million deaths per year from breathing the associated emissions (WHO, 2016). Besides the dangers of indoor air pollution (Lim, 2013; Subramanian, 2014), cooking over open fires also results in deforestation, and greenhouse gas emissions of CO2 and soot (MacCarty 2008; Bailis & Kammen 2005). The ISEC could provide a grass roots solution to these problems. With an Insulated Solar Electric Cooker (ISEC), a 100 W solar panel can be used to directly cook food and provide electricity access and eliminate the health and environmental impacts of biomass cooking. With the addition of a phase change thermal storage the ISEC can cook more rapidly, as well as cook after sunset. The efficiency of this thermal storage is comparable to that of more expensive systems using battery storage and induction cooktops. The phase change medium we use (erythritol) has broad thermal storage utility, and we continue to find ways to increase the efficiency of the use of the stored heat. One important factor for increasing the efficiency of the ISEC technology is that of insulation. Better insulation results in more heat energy being directed into cooking. Current models of our ISEC have the cook pot surrounded by fiberglass inside a larger container. While this provides great insulation the lack of physical stability of this arrangement leads to problems down the road as the fiberglass settles, the cookpot sinks and fiberglass is pushed up over the edges of the pot. In this paper I will document the exploration of various methods to provide the ISEC with stability, without compromising its insulation

Traumatic Neuroma Following Sagittal Split Osteotomy of the Mandible

A 16-year-old male underwent bilateral sagittal split osteotomy of the mandible to correct a mandibular deficiency. Twenty-one years later, a routine panoramic radiograph revealed a radiolucent lesion on the left side of the mandible. The lesion was biopsied. As the patient did not have symptoms and the lesion was connected to the inferior alveolar nerve, the lesion was not totally excised in order to preserve nerve function. The histological features were consistent with traumatic neuroma, and no further surgical procedure was planned

Annular Engine Development Status

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106479/1/AIAA2013-3892.pd

High Thrust-to-Power Annular Engine Technology

Gridded ion engines have the highest efficiency and total impulse of any mature electric propulsion technology, and have been successfully implemented for primary propulsion in both geocentric and heliocentric environments with excellent ground/in-space correlation of performance. However, they have not been optimized to maximize thrust-to-power, an important parameter for Earth orbit transfer applications. This publication discusses technology development work intended to maximize this parameter. These activities include investigating the capabilities of a non-conventional design approach, the annular engine, which has the potential of exceeding the thrust-to-power of other EP technologies. This publication discusses the status of this work, including the fabrication and initial tests of a large-area annular engine. This work is being conducted in collaboration among NASA Glenn Research Center, The Aerospace Corporation, and the University of Michigan

Correlation of tissue concentrations of the pyrethroid bifenthrin with neurotoxicity in the rat

The potential for human exposure to pyrethroid pesticides has prompted pharmacodynamic and pharmacokinetic research to better characterize risk. This work tested the hypothesis that blood and brain concentrations of the pyrethroid bifenthrin are predictive of neurotoxic effects. Adult male Long Evans rats received a single oral dose of bifenthrin dissolved in corn oil. Using figure-eight mazes, motor activity was measured for 1h at 4- and 7-h following exposure to bifenthrin (0-16mg/kg or 0-9mg/kg, respectively; n=4-8/group). Whole blood and brains were collected immediately following motor activity assays. Bifenthrin concentrations in blood and brain were quantified using HPLC/MS/MS. Bifenthrin exposure decreased motor activity from 20% to 70% in a dose-dependent manner at both time points. The relationship between motor activity data and administered dose, and blood and brain bifenthrin concentrations were described using a sigmoidal E max model. The relationships between motor activity and administered dose or blood concentrations were different between the 4- and 7-h time points. The relationship between motor activity and brain concentration was not significantly different between the two time points. These data suggest that momentary brain concentration of bifenthrin may be a more precise dose metric for predicting behavioral effects because the relationship between brain concentration and locomotor activity is independent of the time of exposure.Fil: Scollon, Edward J.. National Health And Environmental Effects Research Laboratory; Estados UnidosFil: Starr, James M.. United States Environmental Protection Agency; Estados UnidosFil: Crofton, Kevin M.. National Health And Environmental Effects Research Laboratory; Estados UnidosFil: Wolansky, Marcelo Javier. National Research Council; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: DeVito, Michael J.. National Health And Environmental Effects Research Laboratory; Estados UnidosFil: Hughes, Michael F.. National Health And Environmental Effects Research Laboratory; Estados Unido

Thrust Stand Characterization of the NASA Evolutionary Xenon Thruster (NEXT)

Direct thrust measurements have been made on the NASA Evolutionary Xenon Thruster (NEXT) ion engine using a standard pendulum style thrust stand constructed specifically for this application. Values have been obtained for the full 40-level throttle table, as well as for a few off-nominal operating conditions. Measurements differ from the nominal NASA throttle table 10 (TT10) values by 3.1 percent at most, while at 30 throttle levels (TLs) the difference is less than 2.0 percent. When measurements are compared to TT10 values that have been corrected using ion beam current density and charge state data obtained at The Aerospace Corporation, they differ by 1.2 percent at most, and by 1.0 percent or less at 37 TLs. Thrust correction factors calculated from direct thrust measurements and from The Aerospace Corporation s plume data agree to within measurement error for all but one TL. Thrust due to cold flow and "discharge only" operation has been measured, and analytical expressions are presented which accurately predict thrust based on thermal thrust generation mechanisms

Far Field Plume Distribution and Divergence for NEXT: DART Mission

In support of the Double Asteroid Redirection Test (DART) mission, laboratory measurements were made on the NEXT ion engine, which will be used for the spacecraft's in-space propulsion [1]. This study revisits a small range of mission-specific 2.7A throttle levels to understand the effect of in-flight flow rate variability, investigate intermediate throttle conditions, and improve measurement methodology. This paper specifically examines the far-field plume divergence and backflow ion flux distribution of the NEXT, while a companion paper examines the charge state distributions