8,807 research outputs found
A map and a pipe : a new approach to characterizing erosion-corrosion regimes of Fe in three dimensions using CFD modelling
In studies of erosion-corrosion, much work has been carried out in recent years to identify regimes of behaviour. Such regimes describe the transition between the erosion and corrosion dominated mechanisms. They can also be used, by assigning various criteria, to identify other regimes of behaviour such as extent of "synergy/antagonism" in the process, so-called "additive" behaviour and the extent of wastage. Despite this work, there has been very little effort to combine the two dimensional erosion-corrosion map with CFD modelling approaches, in which the characteristics of the fluid are accounted for in the regime description. This means that extrapolation of such maps in two dimensions to a three dimensional real surface presents some difficulties. However, it is these surfaces that corrosion engineers are required to tailor, either through modification of the material composition, the surface or the process parameters, for optimum erosion-corrosion resistance. In this paper, a methodology is generated to combine the concepts of CFD modelling, and the erosion-corrosion regime map for a specific geometry and for a range of pure metals in descending order in the Galvanic series. The changes in regimes are presented as a function of variation in the erosion and corrosion variables i.e. particle size, hardness and solution pH. Erosion-corrosion regimes are presented, based on the model results, showing the wide range of mechanistic and wastage mechanisms possible over the component surface
Nepotism or Family Tradition?: A Study of NASCAR Drivers
Of the drivers who raced NASCAR cup series in 2005, 23 of 76 had family connections of either being a son, brother or father of current or former drivers. Given the family connections, some have suggested that the N in NASCAR stands for nepotism. The family tradition of career following, however, is not unique to NASCAR. We see this pattern in many careers such as business, law, politics, agriculture, medicine and entertainment. There are many reasons why children enter the same career as their parents. These include physical-capital transfer, human-capital transfer, brand-nameloyalty transfer, and nepotism. Using a panel data of career statistics for drivers from the last 30 years, we test to see which model best explains career following in NASCAR racing. Our results suggest that the N in NASCAR does not stand for nepotism. Sons, do not have longer careers than non family connected drivers, given the same level of performance. We do find, however, that fathers end their careers earlier than performance indicates when a son enters into cup competition. This could be due to a son’s ability to extend a brand name across generations. The extension of a brand name also occurs with second brothers who benefit from the first brother’s name and having longer careers than performance indicates. If nepotism exits, it occurs only with the second brothers.
Herbaceous Filter Strips in Agroecosystems: Implications for Ground Beetle (Coleoptera: Carabidae) Conservation and Invertebrate Weed Seed Predation
A 9.3-ha crop field flanked by two filter strips was selected to: 1) assess carabid beetle activity-density and community composition and 2) assess post-dispersal weed seed predation by invertebrates in these habitats. Over- all during 1997 and 1998, 12,937 carabid beetles comprising 58 species were collected. Greater species richness and activity-density was observed in filter strips than in the field. A multivariate ordination revealed that year of capture and habitat were important variables conditioning carabid beetle comÂmunities. While two omnivorous species known to eat weed seeds [Harpalus erraticus (Say), Anisodactylus sanctaecrucis (F.)] dominated the 1997 captures, two carnivorous [Pterostichus melanarius (Ill), Pterostichus permundus (Say)] were predominant in 1998. Two omnivorous species, Harpalus pensylvanicus (DeG) and H. erraticus, were primarily captured in filter strips. Weed seed removal was greater in filter strips than in the field. This study shows that habitat management represents a feasible approach to conÂserve beneficial organisms in farmlands
Last Settler’s Syndrome and Land Use Change in Southern Appalachia
In many rural areas land use patterns are shifting from agriculture or woodland to residential development. This is especially true in areas possessing significant natural amenities like the sweeping vistas, white-water rivers, and blue-ridged mountains of Southern Appalachia. As in-migration increases, decisions about land use can become heated as the “newcomers” square off with long-time residents. Understanding how various groups value both the land (as productive resource) and the landscape (as scenic amenity) can help address potential conflict when land use changes. Two independent projects in Watauga County, North Carolina, reflect attempts to understand perspectives on land use through an economic framework and to address land use change from an environmental perspective. Both projects reveal evidence of “last settler’s syndrome”—a tendency among individuals to place a high value on what initially attracted them to a specific place. Both also reveal situations of potential conflict when ideas about land use clash as well as situations for cooperation as various groups share values about land use. Key Words:
Solitude, Silence, and the Training of Psychotherapists: A Preliminary Study
The spiritual disciplines of silence and solitude have long been practiced within the contemplative Christian tradition as a means of character transformation and experiencing God. Do these disciplines affect the use of silence in psychotherapy for Christian clinicians in a graduate training program? Nineteen graduate students in clinical psychology were assigned to a wait-list control condition or a training program involving the disciplines of solitude and silence, and the groups were reversed after the ftrst cohort completed the spiritual disciplines training. One group, which was coincidentally comprised of more introverted individuals, demonstrated a striking increase in the number of silent periods and total duration of silence during simulated psychotherapy sessions during the period of training. The other group, more extraverted in nature, did not show significant changes in therapeutic silence during the training. These results cause us to pose research questions regarding the interaction of personality characteristics and spiritual disciplines in training Christian psychotherapists
The Willingness to Pay to Remove Billboards and Improve Mountain Views
We use the contingent valuation method to measure the amount citizens are willing to pay to improve mountain-view aesthetics through the removal of billboards. Our approach addresses both the perceived property rights as well as the perceptions of the status quo in the southern Appalachian Mountains. We find that individuals who retire to the mountains have different preferences for land use and mountain views than individuals who have ancestors who lived in Watauga County. In the aggregate, we find that citizens are willing to pay up almost one-half million dollars to remove billboards from Watauga County roadsides. This study provides insights to the debate surrounding land use in the mountains.
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