Some calculations on the ground and lowest-triplet state of the helium isoelectronic sequence with the nucleus in motion

The method described in the preceding paper for the solution of two-electron atoms, which was used to calculate the 1 1S and 2 3S states of helium and heliumlike atoms within the fixed-nucleus approximation, has been applied to the case where all three particles are in relative motion. The solutions in the present case automatically include the effects of the mass polarization term and are compared with the results obtained for the term by using first-order perturbation theory with the fixed-nucleus wave functions. The input data for a particular atom consist of the atomic number, as before, but now the corresponding mass of the nucleus must be given also. Nonrelativistic energies with the nuclear mass included in the calculation have been obtained for the 1 1S and 2 3S states for Z ranging from 1 to 10. The energy with the nucleus in motion can be expressed only to eight significant figures (SF's) given the accuracy with which the relevant physical constants are known at present. All the results given here are computed as if these constants were known to ten SF's so that errors not incurred due to rounding. Convergence of the energies to ten SF's for both the singlet and triplet state was reached with a matrix of size 444 for Z values from 2 to 10. Convergence for the H- ion was a little slower

Coated silicon comprising material for protection against environmental corrosion

In accordance with an embodiment of the invention, an article is disclosed. The article comprises a gas turbine engine component substrate comprising a silicon material; and an environmental barrier coating overlying the substrate, wherein the environmental barrier coating comprises cerium oxide, and the cerium oxide reduces formation of silicate glass on the substrate upon exposure to corrodant sulfates

THE EFFECTS OF FARMLAND, FARMLAND PRESERVATION AND OTHER NEIGHBORHOOD AMENITIES ON PROXIMATE HOUSING VALUES: RESULTS OF A CONJOINT ANALYSIS OF HOUSING CHOICE

Using stated-preference data from a choice-based conjoint analysis instrument, we estimate willingness to pay for the presence of neighboring land that is dedicated to agricultural use (versus a developed land use) and for the preservation of surrounding farmland as permanent cropland. The data also elucidate how individuals balance the values associated with nearby agricultural land patterns with other key neighborhood characteristics such as neighborhood parks, housing density, commute times, school quality and neighborhood safety. The median respondent from a randomly chosen sample of Columbus, Ohio homeowners was willing to pay $843 annually to avoid immediate conversion of 10 percent of agricultural land within one mile of the house valued in the conjoint experiment while the same respondent was willing to pay$277 annually to preserve the same amount of farmland as permanent cropland. We find provision of neighborhood parks within housing developments to be a strong substitute for farmland preservation.Land Economics/Use,

A recent history of thermal barrier coatings for aero-propulsion applications

Thermal barrier coatings for aero-propulsion operation have been in use since the 1960s. These thermal barrier coatings are composed of an oxidation resistant metallic base layer and a thermally resistant ceramic top layer. The development and implementation of advances in both the metallic base and the ceramic top layer will be explored. The evolution has included performance and durability improvements, process advances, and understanding and evolution of failure modes. More recent efforts have focus on future challenges for thermal barrier coatings to meet ever increasing operating temperature demands of future applications

Community Ownership of Local Assets: conditions for sustainable success

In the United Kingdom, the transfer of ownership of certain assets to local community control has been a common response to the financial constraints under which local authorities have operated since the global economic crisis of 2008 (Hart, 2010; DSDNI, 2014). Such a process raises important questions over the to understand a process in which community organisations are ‘in some cases, replacing state provision’ (2015: 85). This is particularly challenging for rural and semi rural communities, which Osborne et al (2004) argue may struggle in their attempts at asset management unless strong voluntary engagement and community infrastructure is present. Others such as Murtagh (2015) and Mackenzie (2006; 2012) have identified the challenges in such transfers as well as some of the ways in which communities can avoid ‘dispossession’ of these important community resources. This paper presents research that focuses on the management of two semi-rural assets transferred from local authority into community ownership. The research was conducted partly in conjunction with the Community and Economic Development team at Tewkesbury Borough Council (TBC), Gloucestershire, England, who identified assets in Churchdown and Brockworth as examples of transferred assets run successfully in community ownership. The data comes from a series of interviews with key stakeholders at each asset, and interviews with a Tewkesbury Borough Council Community Development officer. The work makes two contributions to the study of conditions for sustainable community ownership of transferred assets. First, it argues that legitimacy for asset transfer may be established through engaging a wider range of community members and a greater sense of community ownership post-transfer. Such developments pose a potential challenge to narratives that see asset transfer as the result of neoliberal doctrines and as legitimating neoliberal objectives. There is, however, a tension in this debate, expressible as the difference between a forced responsibilisation of communities that might not be equipped for this, and the conditions required for generating ‘collective responsibility’. Second, we add to the analysis of those such as Emery and Flora (2006) and Fisher and McKee (2017) by applying four of Carney’s (1999) sustainable livelihoods categories to an understanding of the essential community capacity required to pursue successful ownerships of assets. We argue that it is the presence of sufficient human, social, physical, and financial capital that creates an ‘institutional thickness’ (Armin and Thrift, 2012) that can help ensure an asset is sustainable in community ownership

The Biology of Wahoo (Acanthocybium solandri) in the Western Central Atlantic

This contribution summarizes aspects of the biology of the wahoo, Acanthocybium solandri (Scombridae), that are pertinent to assessment and management of this species in the western central Atlantic (WCA). In this region wahoo is a target species for both commercial and recreational fisheries, and annual landings appear to have increased steadily over the last 30 years to in excess of 2000 mt. Wahoo is believed to be migratory, but little is known of the migration patterns. Significant seasonal variation in catches within the region indicates that it is seasonally abundant in most locations. Periods of peak abundance occur from the fall through spring in the southeastern and northern Caribbean islands, and are restricted to the warmer months (late spring through early fall) in the more northerly locations (northern Gulf of Mexico, North Carolina, and Bermuda). Wahoo exhibits early sexual maturity (within the first year) and a spawning season that extends from at least May to October. Females are multiple batch spawners and are highly fecund. Limited age and growth studies indicate that it is a relatively fast-growing species, has high mortality, and probably lives for 5-6 years. Wahoo is primarily piscivorous, although some invertebrates including squids are eaten. A relatively small number of parasite species have been associated with it. There is no evidence of more than a single shared stock of wahoo in the WCA, and recent genetic studies, using RAPD markers, suggest that stock boundaries may extend beyond this region. The status of the wahoo resource in the WCA remains unclear. Reliable wahoo catch and fishing effort data from the entire WCA, improved knowledge of migration patterns, reproductive characteristics and critical habitat (e.g., preferred spawning areas), validation of age, growth and mortality estimates, and a more comprehensive analysis of stock structure for the entire Atlantic are needed for informed wahoo stock assessment and management

Social software as support in hybrid learning environments: the value of the blog as a tool for reflective learning and peer support.

This article reports on an investigation of blog technology's potential for encouraging interaction between students, and its consequences in terms of peer learning and peer support, on a module of an accredited library and information science (LIS) degree program. The findings consider the treatment of blogs in the domain of LIS with particular reference to educational settings. Content analysis revealed that blogs offer comparable and additional benefits to other projects designed to encourage reflective engagement with teaching material, such as learning journals. Most notable is the level of shared peer support evident in the online discussions between class members. The findings of this study are of particular interest to LIS educators who seek to develop their consideration of blogs in the classroom; blogs may be seen as learning tools in their own right and not simply an option for providing information online