Advanced thermal barrier coating systems

Current state-of-the-art thermal barrier coating (TBC) systems consist of partially stabilized zirconia coatings plasma sprayed over a MCrAlY bond coat. Although these systems have excellent thermal shock properties, they have shown themselves to be deficient for a number of diesel and aircraft applications. Two ternary ceramic plasma coatings are discussed with respect to their possible use in TBC systems. Zirconia-ceria-yttria (ZCY) coatings were developed with low thermal conductivities, good thermal shock resistance and improved resistance to vanadium containing environments, when compared to the baseline yttria stabilized zirconia (YSZ) coatings. In addition, dense zirconia-titania-yttria (ZTY) coatings were developed with particle erosion resistance exceeding conventional stabilized zirconia coatings. Both coatings were evaluated in conjunction with a NiCr-Al-Co-Y2O3 bond coat. Also, multilayer or hybrid coatings consisting of the bond coat with subsequent coatings of zirconia-ceria-yttria and zirconia-titania-yttria were evaluated. These coatings combine the enhanced performance characteristics of ZCY with the improved erosion resistance of ZTY coatings. Improvement in the erosion resistance of the TBC system should result in a more consistent delta T gradient during service. Economically, this may also translate into increased component life simply because the coating lasts longer

Strategies for stimulating poverty-alleviating growth in the rural nonfarm economy in developing countries:

"The rural nonfarm economy (RNFE) accounts for roughly 25 percent of full-time rural employment and 35-40 percent of rural incomes across the developing world. This diverse collection of seasonal trading, household-based and large-scale agroprocessing, manufacturing and service activities plays a crucial role in sustaining rural populations, in servicing a growing and modern agriculture, and in supplying local consumer goods and services. In areas where landlessness prevails, rural nonfarm activity offers important economic alternatives for the rural poor....Three key groups currently intervene in the rural nonfarm economy: large private enterprises, non-profit promotional agencies and governments. Large modern corporations take investment, procurement and marketing decisions that powerfully shape opportunities in the rural nonfarm economy throughout much of the Third World...." The authors put forth three basic principles for policy makers who want to ensure equitable growth of the RNFE : (1) Identify key engines of regional growth; (2) Focus on subsector-specific supply chains; and (3) Build flexible institutional coalitions. They conclude that "a prosperous rural nonfarm economy can contribute to both aggregate economic growth and improved welfare of the rural poor." from Executive Summary.Poverty alleviation Developing countries., Rural population., Employment, Non-agricultural Rural areas., Manufacturing industries., Service industries.,

Transforming the rural nonfarm economy: Opportunities and threats in the developing world

"Rural residents across the developing world earn a large share of their income—35–50 percent—from nonfarm activities. Agricultural households count on nonfarm earnings to diversify risk, moderate seasonal income swings, and finance agricultural input purchases, whereas landless and near-landless households everywhere depend heavily on nonfarm income for their survival. Over time, the rural nonfarm economy has grown rapidly, contributing significantly to both employment and rural income growth. Long neglected by policymakers, the rural nonfarm economy has attracted considerable attention in recent years. In poor agrarian countries struggling with growing numbers of marginal farmers and lackluster agricultural performance, such as those in much of Africa, policymakers view the rural nonfarm economy as a potential alternative to agriculture for stimulating rural income growth. In countries whose economies are successfully shifting from agriculture to other sectors, policymakers see the rural nonfarm economy as a sector that can productively absorb the many agricultural workers and small farmers being squeezed out of agriculture by increasingly commercialized and capitalintensive modes of farming. Given frequently low capital requirements in the nonfarm economy, policymakers in both settings view the rural nonfarm economy as offering a potential pathway out of poverty for many of their rural poor. Expectations everywhere are high. How realistic are these expectations? Can the rural nonfarm economy indeed grow rapidly enough to productively absorb a growing rural labor force? And in doing so, can it, in fact, provide a pathway out of poverty for the rural poor? A recent book published for IFPRI by Johns Hopkins University Press and Oxford University Press in India, Transforming the Rural Nonfarm Economy: Opportunities and Threats in the Developing World, marshals empirical evidence from around the globe to explore these key policy questions. The book, edited by Steven Haggblade, Peter B. R. Hazell, and Thomas Reardon, examines key factors affecting growth and equity in the rural nonfarm economy in order to identify settings and policies that favor rural nonfarm growth and enable the poor to participate in growing segments of the evolving rural nonfarm economy." from textAgricultural industries Developing countries, Agriculture Economic aspects Developing countries, Developing countries Rural conditions., Nonfarm economy,

A rural agricultural-sustainable energy community model and its application to Felton Valley, Australia

Energy and food security require a delicate balance which should not threaten or undermine community prosperity. Where it is proposed to derive energy from conventional fossil fuel resources (such as coal, shale oil, natural gas, coal seam gas) located in established rural areas, and particularly where these areas are used for productive agricultural purposes, there are often both intense community concern as well as broader questions regarding the relative social, economic and environmental costs and benefits of different land uses and, increasingly, different energy sources. The advent of mainstream renewable energy technologies means that alternative energy options may provide a viable alternative, allowing energy demand to be met without compromising existing land uses. We demonstrate how such a Sustainable Energy Rural Model can be designed to achieve a balance between the competing social goals of energy supply, agricultural production, environmental integrity and social well-being, and apply it to the Felton Valley, a highly productive and resilient farming community in eastern Australia. Research into available wind and solar resources found that Felton Valley has a number of attributes that indicate its suitability for the development of an integrated renewable energy precinct which would complement, rather than displace, existing agricultural enterprises. Modelling results suggest a potential combined annual renewable energy output from integrated wind and solar resources of 1,287 GWh/yr from peak installed capacity of 713 MW, sufficient to supply the electrical energy needs of about 160,000 homes, in combination with total biomass food production of 31,000 tonnes per annum or 146 GWh/yr of human food energy. The portfolio of renewable energy options will not only provide energy source diversity but also ensures long-term food security and regional stability. The Felton Valley model provides an example of community-led energy transformation and has potential as a pilot project for the development of smart distributed grids that would negate the need for further expansion of coal mining and coal fired power stations

On the Measurement of “Grayness” of Cities

We consider a situation where individuals belonging to multiple groups inhabit a space that can be divided into smaller distinguishable units, a feature characterizing many cities in the world. When data on an economic attribute (in our case, income) is available, we conceptualize a phenomenon that we refer to as “Grayness” - a combination of spatial integration based upon group-identity and income. Grayness is high when cities display a high degree of spatial co-existence in terms of both identity and income. We lay down some desirable properties of a measure of Grayness and develop a simple and intuitive index that satisfies them. We provide an illustration by using data from the Indian city of Hyderabad, and selected American cities

A new B-dot probe-based diagnostic for amplitude, polarization, and wavenumber measurements of ion cyclotron range-of frequency fields on ASDEX Upgrade

A new B-dot probe-based diagnostic has been installed on an ASDEX Upgrade tokamak to characterize ion cyclotron range-of frequency (ICRF) wave generation and interaction with magnetized plasma. The diagnostic consists of a field-aligned array of B-dot probes, oriented to measure fast and slow ICRF wave fields and their field-aligned wavenumber (k(//)) spectrum on the low field side of ASDEX Upgrade. A thorough description of the diagnostic and the supporting electronics is provided. In order to compare the measured dominant wavenumber of the local ICRF fields with the expected spectrum of the launched ICRF waves, in-air near-field measurements were performed on the newly installed 3-strap ICRF antenna to reconstruct the dominant launched toroidal wavenumbers (k(tor)). Measurements during a strap current phasing scan in tokamak discharges reveal an upshift in k(//) as strap phasing is moved away from the dipole configuration. This result is the opposite of the k(tor) trend expected from in-air near-field measurements; however, the near-field based reconstruction routine does not account for the effect of induced radiofrequency (RF) currents in the passive antenna structures. The measured exponential increase in the local ICRF wave field amplitude is in agreement with the upshifted k(//), as strap phasing moves away from the dipole configuration. An examination of discharges heated with two ICRF antennas simultaneously reveals the existence of beat waves at 1 kHz, as expected from the difference of the two antennas' operating frequencies. Beats are observed on both the fast and the slow wave probes suggesting that the two waves are coupled outside the active antennas. Although the new diagnostic shows consistent trends between the amplitude and the phase measurements in response to changes applied by the ICRF antennas, the disagreement with the in-air near-field measurements remains. An electromagnetic model is currently under development to address this issue. (C) 2015 AIP Publishing LLC

Statistical Analysis of Small Ellerman Bomb Events

The properties of Ellerman bombs (EBs), small-scale brightenings in the H-alpha line wings, have proved difficult to establish due to their size being close to the spatial resolution of even the most advanced telescopes. Here, we aim to infer the size and lifetime of EBs using high-resolution data of an emerging active region collected using the Interferometric BIdimensional Spectrometer (IBIS) and Rapid Oscillations of the Solar Atmosphere (ROSA) instruments as well as the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO). We develop an algorithm to track EBs through their evolution, finding that EBs can often be much smaller (around 0.3") and shorter lived (less than 1 minute) than previous estimates. A correlation between G-band magnetic bright points and EBs is also found. Combining SDO/HMI and G-band data gives a good proxy of the polarity for the vertical magnetic field. It is found that EBs often occur both over regions of opposite polarity flux and strong unipolar fields, possibly hinting at magnetic reconnection as a driver of these events.The energetics of EB events is found to follow a power-law distribution in the range of "nano-flare" (10^{22-25} ergs).Comment: 19 pages. 7 Figure

SRB Environment Evaluation and Analysis. Volume 3: ASRB Plume Induced Environments

Contract NAS8-37891 was expanded in late 1989 to initiate analysis of Shuttle plume induced environments as a result of the substitution of the Advanced Solid Rocket Booster (ASRB) for the Redesigned Solid Rocket Booster (RSRB). To support this analysis, REMTECH became involved in subscale and full-scale solid rocket motor test programs which further expanded the scope of work. Later contract modifications included additional tasks to produce initial design cycle environments and to specify development flight instrumentation. Volume 3 of the final report describes these analyses and contains a summary of reports resulting from various studies