158 research outputs found
Natural attenuation of dissolved petroleum fuel constituents in a fractured Chalk aquifer: Contaminant mass balance with probabilistic analysis
A plume-scale mass balance is developed to assess the natural attenuation (NA) of dissolved organic contaminants in fractured, dual porosity aquifers. This methodology can be used to evaluate contaminant distribution within the aquifer, plume source term, contaminant biodegradation and plume status. The approach is illustrated for a site on the UK Upper Chalk aquifer impacted by petroleum fuel containing MTBE and TAME. Variability in site investigation data and uncertainty in the mass balance was assessed using probabilistic analysis. The analysis shows that BTEX compounds are biodegraded primarily by denitrification and sulphate reduction in the aquifer, with an equivalent plume-scale first-order biodegradation rate of 0.49 year-1. Other biodegradation processes are less important. Sorption contributes to hydrocarbon attenuation in the aquifer but is less important for MTBE and TAME. Uncertainty in the plume source term and site hydrogeological parameters had the greatest effect on the mass balance. The probabilistic analysis enabled the most likely long-term composition of the plume source term to be deduced and provided a site-specific estimate of contaminant mass flux for the prediction of plume development. The mass balance methodology provides a novel approach to improve NA assessments for petroleum hydrocarbons and other organic contaminants in these aquifer settings
Interactive three-dimensional boundary element stress analysis of components in aircraft structures
Computer aided design of mechanical components is an iterative process that often involves multiple stress analysis runs; this can be time consuming and expensive. Significant efficiency improvements can be made by increasing interactivity at the conceptual design stage. One approach is through real-time re-analysis of models with continuously updating geometry. Thus each run can benefit from an existing mesh and governing boundary element matrix that are similar to the updated geometry. For small problems, amenable to real-time analysis, re-integration accounts for the majority of the re-analysis time. This paper assesses how efficiency can be achieved during re-integration through both algorithmic and hardware based methods. For models with fewer than 10,000 degrees of freedom, the proposed algorithm performs up to five times faster than a standard integration scheme. An additional six times speed is achieved on eight cores over the serial implementation. By combining this work with previously addressed meshing and solution schemes, real-time re-analysis becomes a reality for small three-dimensional problems. Significant acceleration of larger systems is also achieved. This work demonstrates the viability of application in the aerospace industry where rapid validation of a range of similar models is an essential tool for optimising aircraft designs
The Role of Verbal Competence and Multiple Risk on the Internalizing Behavior Problems of Costa Rican Youth
This longitudinal study examined internalizing behavior problems (anxiety/depression) in early adolescence in relation to adversity in early childhood and child verbal competence. We hypothesized that verbal competence would act as a protective factor in the face of early adversity, that is, high verbal IQ would predict relatively lower internalizing problems in early adolescence primarily for those children who experienced the greatest adversity. The sample was based on 191 Costa Rican children and their mothers, who were recruited in infancy from an urban community and assessed again at 5 and 11â14 years. Families were generally lower-middle to working class. A total of 165 children (94 boys) participated in the early adolescent follow-up (mean age = 12.3 years). Internalizing problems were based on maternal report (Spanish Child Behavior Checklist). Our cumulative risk index (CRI)_of adversity in early childhood consisted of home environment quality (HOME score), socioeconomic status, maternal depressed mood (CESD), and maternal IQ. Controlling for the effects of age, gender, internalizing problems at 5 years, and verbal IQ at 5 years, there was a significant interaction between early adversity and verbal IQ at age 11â14 years in predicting internalizing problems in early adolescence. Youth with high verbal IQ had comparable levels of internalizing problems regardless of high or low adversity in early childhood. In contrast, youth with low verbal IQ received higher internalizing problem ratings if they experienced high adversity early in life. The results raise the possibility that interventions to improve verbal competence might help lower the risk of internalizing problems in the face of early adversity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75135/1/annals.1376.034.pd
Interactive three-dimensional boundary element stress analysis of components in aircraft structures
A Systematic Literature Review of Emotion Regulation Measurement in Individuals With Autism Spectrum Disorder
DOI: 10.1002/aur.1426Emotion regulation (ER) difficulties are a potential common factor underlying the presentation of multiple emotional and behavioral problems in individuals with Autism Spectrum Disorder (ASD). To provide an overview of how ER has been studied in individuals with ASD, we conducted a systematic review of the past 20 years of ER research in the ASD population, using established keywords from the most comprehensive ER literature review of the typically developing population to date. Out of an initial sampling of 305 studies, 32 were eligible for review. We examined the types of methods (self-report, informant report, naturalistic observation/ behavior coding, physiological, and open-ended) and the ER constructs based on Gross and Thompsonâs modal model (situation selection, situation modification, attention deployment, cognitive change, and response modulation). Studies most often assessed ER using one type of method and from a unidimensional perspective. Across the 32 studies, we documented the types of measures used and found that 38% of studies used self-report, 44% included an informant report measure, 31% included at least one naturalistic observation/behavior coding measure, 13% included at least one physiological measure, and 13% included at least one open-ended measure. Only 25% of studies used more than one method of measurement. The findings of the current review provide the field with an in-depth analysis of various ER measures and how each measure taps into an ER framework. Future research can use this model to examine ER in a multicomponent way and through multiple methods.Spectrum of Hope Autism Foundation, Canadian Institutes of Health Research, NeuroDevNet, Sinneave Family Foundation, CASDA, Autism Speaks Canada, Health Canad
Research Review: Recommendations for reporting on treatment trials for child and adolescent anxiety disorders â an international consensus statement
A systematic review of the effects of exercise interventions on body composition in HIV+ adults
Over the years, physical activity and exercise have been used to positively impact the health and quality of life of persons infected with HIV and, more recently, has been associated with a spectrum of body composition changes. The aim of this review was to examine the effects of various exercise interventions on body composition in HIV positive adults, using a search strategy of randomized, controlled trials (RCTs). A systematic review was performed by five independent reviewers using a predetermined protocol adapted from previous research for assessing the articles for inclusion, the extracted data, and methodological quality. Eight RCTs involving 430 (26% female) HIV positive adults performing exercise a minimum of thrice weekly for at least six weeks were finally selected: Four were progressive resistance training (PRT) studies, three were aerobic training (AT) studies, and one involved yoga. In the PRT studies, there were significant increases in three anthropometric measures, namely, body mass, sum of skinfolds and sum of limb girths. In the AT studies, significant decreases were found in seven anthropometric measures, namely, body mass index, waist-hip ratio, body mass, triceps skinfold, waist circumference and sum of skinfolds. With yoga, the changes were nonsignificant. Exercise contributes to improved body composition and, when applied safely, appears to be beneficial for adults living with HIV/AIDS. However, these findings should be interpreted cautiously due to the relatively few RCTs published to date. Future studies would benefit from increased attention to sample size, female participants, participant follow-up, complete statistical analysis and intention-to-treat analysis.Scopu
Communication is key: a study of the development of communication key skills in China
Different countries offer alternative curricula around what might be designated language, literacy and/or communication. This paper focuses on the latter which has typically been associated with vocational education and often labelled a âkeyâ or âcoreâ skill that forms part of a wider set of life and employability skills. In recent years, as China has emerged as a global economy, education has been significant in its policy and development. This research explores staff and student responses to the introduction of a key skills communication course in three Chinese further education vocational colleges. The initiative was prompted by research in China which had suggested that communication is important not just for education (Ye and Li 2007) but also for employability, and that the ability to communicate effectively could be instrumental in individualsâ success and development (Tong and Zhong 2008). It explores what communication key skills might mean in a Chinese context and questions notions of transferability and of competence and performance in communication. It analyses how motivation could affect learner success and the relationship of pedagogy to curriculum and, finally, it considers how communication might be an element in the longer-term social and political development of critical literacies
Avaliação da atividade cicatrizante do jucå (Caesalpinia ferrea Mart. ex Tul. var. ferrea) em lesþes cutâneas de caprinos
Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET
The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR
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