Creep fatigue life prediction for engine hot section materials (isotropic): Fourth year progress review

As gas turbine technology continues to advance, the need for advanced life prediction methods for hot section components is becoming more and more evident. The complex local strain and temperature histories at critical locations must be accurately interpreted to account for the effects of various damage mechanisms (such as fatigue, creep, and oxidation) and their possible interactions. As part of the overall NASA HOST effort, this program is designed to investigate these fundamental damage processes, identify modeling strategies, and develop practical models which can be used to guide the early design and development of new engines and to increase the durability of existing engines

Creep fatigue life prediction for engine hot section materials (isotropic): Third year progress review

This program is designed to investigate fundamental damage processes, identify modeling strategies, and develop practical models which can be used to guide the early design and development of new engines and to increase the durability of existing engines. A review is given of the base program, completed in 1984, which included the comparison and evaluation of several popular high-temperature life prediction approaches as applied to continuously cycled isothermal specimen tests. The option program, of which one year is completed, is designed to develop models which can account for complex cycles and loadings, such as thermomechanical cycling, cumulative damage, multiaxial stress/strain rates, and environmental effects

Creep fatigue life prediction for engine hot section materials (ISOTROPIC)

The specific activities summarized include: verification experiments (base program); thermomechanical cycling model; multiaxial stress state model; cumulative loading model; screening of potential environmental and protective coating models; and environmental attack model

The current distribution on resistive linear antennas

Mathematical model for computing resistive loss effects on current distribution of thin cylindrical antenna

Creep fatigue life prediction for engine hot section materials (isotropic)

A series of high temperature strain controlled fatigue tests have been completed to study the effects of thermomechanical fatigue, multiaxial loading, reactive environments, and imposed mean stresses. The baseline alloy used in these tests was cast B1900+Hf (with and without coatings); a small number of tests of wrought INCO 718 are also included. A strong path dependence was demonstrated during the thermomechanical fatigue testing, using in-phase, out-phase, and non-proportional (elliptical and 'dogleg') strain-temperature cycles. The multiaxial tests also demonstrated cycle path to be a significant variable, using both proportional and non-proportional tension-torsion loading. Environmental screening tests were conducted in moderate pressure oxygen and purified argon; the oxygen reduced the specimen lives by two, while the argon testing produced ambiguous data. Both NiCoCrAlY overlay and diffusion aluminide coatings were evaluated under isothermal and TMF conditions; in general, the lives of the coated specimens were higher that those of uncoated specimens. Controlled mean stress TMF tests showed that small mean stress changes could change initiation lives by orders of magnitude; these results are not conservatively predicted using traditional linear damage summation rules. Microstructures were evaluated using optical, SEM and TEM methods

A Closer Look At Neighborhood Conservation Districts: West Hillsborough Neighborhood, NC

The purpose of this study is to investigate the process of establishing a Neighborhood Conservation District (NCD) for the West Hillsborough Neighborhood in the Town of Hillsborough, NC. The West Hillsborough Neighborhood, one of Hillsborough's older and most distinctive neighborhoods, sits adjacent to the Bellevue Manufacturing Company and the Eno Cotton Mill. Hillsborough, like many other small towns in the United States, is facing rapid development and growth pressures. Neighborhood Conservation Districts have become an increasingly popular tool used by planners to safeguard the distinct local character of neighborhoods. In order to better understand the process of forming an NCD, the criteria for establishing one and the various approaches to them, three case studies will be examined in North Carolina. The case studies include: Northside, Chapel Hill, Avent West, Raleigh, and Cedar Street, Greensboro, all of which are at different phases of the implementation process of writing a NCD into their zoning ordinance.Master of City and Regional Plannin

Fine Particulate Matter (PM(2.5)) Air Pollution and Selected Causes of Postneonatal Infant Mortality in California

Studies suggest that airborne particulate matter (PM) may be associated with postneonatal infant mortality, particularly with respiratory causes and sudden infant death syndrome (SIDS). To further explore this issue, we examined the relationship between long-term exposure to fine PM air pollution and postneonatal infant mortality in California. We linked monitoring data for PM ≤2.5 μm in aerodynamic diameter (PM(2.5)) to infants born in California in 1999 and 2000 using maternal addresses for mothers who lived within 5 miles of a PM(2.5) monitor. We matched each postneonatal infant death to four infants surviving to 1 year of age, by birth weight category and date of birth (within 2 weeks). For each matched set, we calculated exposure as the average PM(2.5) concentration over the period of life for the infant who died. We used conditional logistic regression to estimate the odds of postneonatal all-cause, respiratory-related, SIDS, and external-cause (a control category) mortality by exposure to PM(2.5), controlling for the matched sets and maternal demographic factors. We matched 788 postneonatal infant deaths to 3,089 infant survivors, with 51 and 120 postneonatal deaths due to respiratory causes and SIDS, respectively. We found an adjusted odds ratio for a 10−μg/m(3) increase in PM(2.5) of 1.07 [95% confidence interval (CI), 0.93–1.24] for overall postneonatal mortality, 2.13 (95% CI, 1.12–4.05) for respiratory-related postneonatal mortality, 0.82 (95% CI, 0.55–1.23) for SIDS, and 0.83 (95% CI, 0.50–1.39) for external causes. The California findings add further evidence of a PM air pollution effect on respiratory-related postneonatal infant mortality

Placemaking in Metro East Springfield - Creating a Landscape Framework

PLACEMAKING IN METRO EAST SPRINGFIELD - Creating a Landscape Framework Placemaking in Metro East Springfield – Creating a Landscape Framework provides strategies to use the landscape as a framework for rebuilding community in a downtown urban area that has “good bones” but has been neglected and overlooked for decades. A catalyst for the development of project area is the recent acquisition of the historical 1916 Willys Overland building through a developer. The Graduate Urban Design Studio 2018 developed five proposals for urban revitalization in the area that are centered on the landscape. The programming of the proposals was developed in collaboration with neighborhood representatives and stakeholders of the area. The public response was very positive and the project got recognized in the local press and media. The Landscape Framework is interwoven with cultural activities such as public art and education, new opportunities for small neighborhood commerce, future employment and possibilities for new housing. The Landscape Framework will bring expand urban greening and will reduce heat island effects to reduce the impact of climate change. The presented Landscape Framework will guide the future of the area as overlapping and simultaneous measures. They encompass: Tangible tactile interventions on streets, facades and underutilized lots that change the perception of the landscape at low cost but are highly effective. New parks that create areas for recreation and contemplation. Greenway promenades connect to shorten long blocks and create a network to the neighboring residential areas. Establishment of urban agriculture activities to build community, provide food security and education. Collaboration with existing organizations in Springfield that are actively involved with urban agriculture: Gardening the Community (GTC) Springfield, Wellspring Harvest first commercial hydroponic greenhouse, UMass Extension and UMass Permaculture, Springfield Technical Community College (STCC). Walkable streets through extensive street tree plantings, widening of sidewalks, adding bicycle lanes and introducing shared multi-functional streets for community events. Stormwater Management through bioswales along streets, green roofs, larger infiltration areas in new parks and porous pavement. Promotion of alternative stormwater management through education and artistic interventions. People want to connect culturally and socially. Creating a sense of place, common ownership, and connectivity are a vital part of a sustainable community. This includes: Complimentary cultural, art, craft and education at new Maker-Spaces. Daycare Center and other childcare services. Outdoor pop-up business opportunities for food vendors such as food carts and trucks. Indoor pop-up business opportunities in abandoned or underutilized buildings. Adaptive reuse of existing architecture and infill. Diversification of housing market with inclusion of market-rate housing to create a more balanced economy. Legal framework through zoning changes and permitting that supports small businesses, reduces bureaucratic burdens and secures public open green space