Effects of well spacing on geological storage site distribution costs and surface footprint

Geological storage studies thus far have not evaluated the scale and cost of the network of distribution pipelines that will be needed to move CO(2) from a central receiving point at a storage site to injection wells distributed about the site. Using possible injection rates for deep-saline sandstone aquifers, we estimate that the footprint of a sequestration site could range from <100 km(2) to >100,000 km(2), and that distribution costs could be <$0.10/tonne to >$10/tonne. Our findings are based on two models for determining well spacing: one which minimizes spacing in order to maximize use of the volumetric capacity of the reservoir, and a second that determines spacing to minimize subsurface pressure interference between injection wells. The interference model, which we believe more accurately reflects reservoir dynamics, produces wider well spacings and a counterintuitive relationship whereby total injection site footprint and thus distribution cost declines with decreasing permeability for a given reservoir thickness. This implies that volumetric capacity estimates should be reexamined to include well spacing constraints, since wells will need to be spaced further apart than void space calculations might suggest. We conclude that site-selection criteria should include thick, low-permeability reservoirs to minimize distribution costs and site footprint.     

The need for smart transducers: an aerospace test and evaluation perspective

This article deals with the use of smart transducers in the aerospace community. The use of smart sensors has the potential to reduce the cost of installing and operating test measurement systems. Aerospace Test and Evaluation (T&E) community has not fully embraced smart transducers. There are some in use, but they tend to be built to proprietary standards. The IEEE 1451 family of standards addresses the problems that face by this community as well as other transducer users.     

In search of the powerful self-fulfilling prophecy.

This research examined moderators of naturally occurring self-fulfilling prophecies. The authors assessed whether positive or negative self-fulfilling prophecies were more powerful and whether some targets were more susceptible to self-fulfilling prophecies because of their self-concepts in a particular achievement domain and previous academic records. Participants were 98 teachers and 1,539 students in sixth-grade public school math classes. Results yielded a strong pattern showing that teacher perceptions predicted achievement more strongly for low achievers than for high achievers. Results also yielded a much weaker pattern showing that teacher overestimates predicted achievement more strongly than teacher underestimates. Implications for social perceptual accuracy, self-enhancement theory, and understanding when self-fulfilling prophecies are stronger are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parents, Peers, and Problem Behavior: A Longitudinal Investigation of the Impact of Relationship Perceptions and Characteristics on the Development of Adolescent Problem Behavior.

This study examined longitudinal relations among adolescents' family relationships, peer relationships, and problem behavior. Participants were 1,357 African American and European American adolescents who were interviewed at 3 time points: 7th grade (mean age=12.7 years), the summer after 8th grade (mean age=14.2 years), and 11th grade (mean age=17.1 years). For all racial and gender groups, 7th-grade family characteristics (youth perceptions of autonomy and warmth) predicted a risky peer context during 8th grade, which in turn predicted problem behavior during 11th grade. Additionally, problem behavior in the 7th grade predicted 11th-grade problem behavior, directly as well as indirectly through the peer context. Racial and gender differences are discussed, as are implications for future research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Further delineation of renal-coloboma syndrome in patients with extreme variability of phenotype and identical PAX2 mutations

Renal-coloboma syndrome is a recently described autosomal dominant syndrome of abnormal optic nerve and renal development. Two families have been reported with renal-coloboma syndrome and mutations of the PAX2 gene. The PAX2 gene, which encodes a DNA-binding protein, is expressed in the developing ear, CNS, eye, and urogenital tract. Ocular and/or renal abnormalities have been consistently noted in the five reports of patients with renal-coloboma syndrome, to date, but PAX2 expression patterns suggest that auditory and CNS abnormalities may be additional features of renal-coloboma syndrome. To determine whether additional clinical features are associated with PAX2 mutations, we have used PCR-SSCP to identify PAX2 gene mutations in patients. We report here four patients with mutations in exon 2, one of whom has severe ocular and renal disease, microcephaly, and retardation, and another who has ocular and renal disease with high-frequency hearing loss. Unexpectedly, extreme variability in clinical presentation was observed between a mother, her son, and an unrelated patient, all of whom had the same PAX2 mutation as previously described in two siblings with renal-coloboma syndrome. These results suggest that a sequence of seven Gs in PAX2 exon 2 may be particularly prone to mutation.     

Academic and emotional functioning in early adolescence: longitudinal relations, patterns, and prediction by experience in middle school

Adopting a motivational perspective on adolescent development, these two companion studies examined the longitudinal relations between early adolescents' school motivation (competence beliefs and values), achievement, emotional functioning (depressive symptoms and anger), and middle school perceptions using both variable- and person-centered analytic techniques. Data were collected from 1041 adolescents and their parents at the beginning of seventh and the end of eight grade in middle school. Controlling for demographic factors, regression analyses in Study 1 showed reciprocal relations between school motivation and positive emotional functioning over time. Furthermore, adolescents' perceptions of the middle school learning environment (support for competence and autonomy, quality of relationships with teachers) predicted their eighth grade motivation, achievement, and emotional functioning after accounting for demographic and prior adjustment measures. Cluster analyses in Study 2 revealed several different patterns of school functioning and emotional functioning during seventh grade that were stable over 2 years and that were predictably related to adolescents' reports of their middle school environment. Discussion focuses on the developmental significance of schooling for multiple adjustment outcomes during adolescence.     

A CORRELLATION FOR CYLINDER-TO-BED HEAT TRANSFER IN AERATED VIBRATED BEDS OF SMALL PARTICLES

Beds of alumina particles (d_p= 27 μm and 100 μm) were vibrated in the vertical direction at frequencies frdm 0-25 Hz and half-amplitudes from 0-4 mm. Air flow rate through a single-hole or multiple-holes bottom plate varied from 0 to 2 times the minimum fluidizing velocity. The contact heat transfer coefficients at resonance are much higher than those in packed beds and in vibrated fluidized beds (up to 1.2 times). The high heat transfer rates are due to enhanced particle mobility which reaches a maximum at the resonant point. A simple semi-empirical correlation is developed for contact heat transfer which is based on particle mobility. Heat transfer coefficients are correlated with frequency using amplitude, bed height and particle size as adjustable parameters. The correlation is found explain the observed trends in the data reasonably well over the range of parameters studied.     

The effect of surfactants on peat dewatering

The effect of cationic, anionic and neutral surfactants on the mechanical dewatering of a highly decomposed fuelgrade peat has been examined. Surfactant adsorption and zeta potential of the peat particles correlated with dewatering of peat samples. The cationic surfactants had large positive effects on dewatering, the anionic surfactants had a negative effect while the neutral surfactant had no effect. The effects of the surfactants could be explained by charge neutralization and double layer suppression. The cationic surfactants were superior to analogous organic salts because of enhanced interaction by the hydrophobic effect.