X-Ray Photoelectron Spectroscopy to Examine Molecular Composition

The extreme ultraviolet (EUV) spectrum is becoming increasingly important. Its most promising applications include lithography for integrated circuits, space-based astronomy, and medical microscopes. Unfortunately, the optical constants of materials, particularly heavy metals, in this range are not well known. This work examines the molecular composition and oxidation rate and depth of thorium. Most of our data is collected through the use of X-ray Photoelectron Spectroscopy (XPS). XPS utilizes the photoelectric effect to obtain data about the exact composition of our material. X-rays are directed at the surface in question, colliding with and dispelling electrons from different energy levels of atoms. By measuring the number of electrons dispelled and their energies, the presence and quantities of elements can be determined. Depth profiling is done to examine the deeper layers of the sample, in which layers are etched off and new data is obtained. The results are then compared with existing literature. These methods are used to determine what chemical bonding occurs on the surface, whether or not it is diffused into lower layers, over what amount of time, and how the chemical composition varies with depth

Use of Oral Language General Outcome Measures to Describe Children According to Language Status

The purpose of the study was to determine if short language samples can effectively distinguish children with language impairments from those who are typically developing. Four elicitation methods (individual picture descriptions, multi-scene picture description, narrative, and interview) were administered to 14 typically developing children and 3 children with language impairments in Chapel Hill, NC as well as to 16 typically developing children in Greenville, NC. Each task was administered 3 times and lasted 1 minute. All samples were collected and transcribed by the principal investigator and then analyzed using 5 general language sample measures (Number of Total Words, Number of Different Words, Number of Total Utterances, Mean Length of Utterance, Errors/Omissions). Intercorrelations between the elicitation tasks were found for each measure and then the effect size was determined comparing the typically developing children and children with language impairments in Chapel Hill, NC. Significant correlations were observed between most measures. A review of the correlation strength revealed the strongest relationships between the descriptions of individual pictures and multi-scene picture description tasks. Notable differences were observed between children with language impairments and typically developing children. The largest group differences were observed for the Number of Different Words measure. The results suggest that the short language samples produce meaningful information and are clinically feasible.  M.S

Theoretische Untersuchung zur Stabilität der Strömung in einem konvergenten Mikrospalt bei Benetzung

Die vorliegende Arbeit beschäftigt sich theoretisch mit einem instabilen Beschichtungsprozess. Dabei liegt der Schwerpunkt auf eine Keilströmung, die sich zwischen bewegter Wand und der freien Grenzfläche im entnetzenden Fluid einstellt. Ein Satz von Grundgleichungen wird für verschiedene Strömungsformen hergeleitet. Die Grundströmungen werden desweiteren mit einer dreidimensionalen, zeitabhängigen kleinen Störung gestört. Eine Diskussion der Stabilitätsergebnisse findet statt

Big Fish and Other School Effects on Academic Self-Concept

A substantial amount of research indicates that academic self-concept is a function of both individual characteristics, and school effects that impact on the development of self-perceptions. Few studies have studied a cohort of students as they progress through the transition from elementary to middle school. The present study uses multi-level modeling to examine school effects on students’ academic self-concept in reading and math as they transition from elementary to middle school. Data come from the ECLS-K data set. Few school effects were found, but students’ SES was found to be a strong moderator of the relationship between reading achievement and self-perceptions of students’ ability and interest in reading

Self-concepts of adolescents with learning disabilities: A large-scale database study

Using the ELS: 2002 national database, we compared the self-concepts in reading, math, and general academic areas for students with and without identified learning disabilities. Unlike most similar research, students’ measured achievement in reading and math was controlled, thereby effectively comparing students at similar levels of achievement. When controlling for achievement, academic self-concepts were not lower for the students with LD. Similar to other studies, students with LD tended to statistically over-predict their achievement compared to the non-LD group

Urbanicity and Academic Self-Concept

The main focus of this study was the relationships between school urbanicity (size of community in which the school is located) and fifth-grade students’ academic self-concepts. Using multi-level modeling methodology (HLM) we were able to investigate “school effects”, net of individual students’ characteristics. School urbanicity had no effect on reading, math, or general academic self-concept. School-level effects were found consistently for aggregate school achievement in reading and math, congruent with Marsh’s Big-Fish-Little-Pond effect. Less consistent school-level effects were found for proportion of minority students and school-average SES. Individual level effects mirrored those reported in other literature with tested achievement having the greatest effec

Determining Sequential Micellization Steps of Bile Salts With Multi-cmc Modeling

Hypothesis Bile salts exhibit complex concentration-dependent micellization in aqueous solution, rooted in a long-standing hypothesis of increasing size in bile aggregation that has historically focused on the measurement of only one CMC detected by a given method, without resolving successive stepwise aggregates. Whether bile aggregation is continuous or discrete, at what concentration does the first aggregate form, and how many aggregation steps occur, all remain as open questions. Experiments Bile salt critical micelle concentrations (CMCs) were investigated with NMR chemical shift titrations and a multi-CMC phase separation modeling approach developed herein. The proposed strategy is to establish a correspondence of the phase separation and mass action models to treat the first CMC; subsequent micellization steps, involving larger micelles, are then treated as phase separation events. Findings The NMR data and the proposed multi-CMC model reveal and resolve multiple closely spaced sequential preliminary, primary, and secondary discrete CMCs in dihydroxy and trihydroxy bile salt systems in basic (pH 12) solutions with a single model of one NMR data set. Complex NMR data are closely explained by the model. Four CMCs are established in deoxycholate below 100 mM (298 K, pH 12): 3.8 ± 0.5 mM, 9.1 ± 0.3 mM, 27 ± 2 mM, and 57 ± 4 mM, while three CMCs were observed in multiple bile systems, also under basic conditions. Global fitting leverages the sensitivity of different protons to different aggregation stages. In resolving these closely spaced CMCs, the method also obtains chemical shifts of these spectroscopically inaccessible (aka dark) states of the distinct micelles

An eating disorder randomized clinical trial and attrition: Profiles and determinants of dropout

Objective: This study sought to determine whether differential treatment effects in the targeted mechanisms of change and eating disorder (ED) symptoms are associated with patterns of attrition from a RCT. Method: The main study was a RCT of a psychotherapy designed to alter the non-weight related self-cognitions as the means to promote recovery and health in a sample of 69 women with AN or BN. Four groups based on point of dropout were compared on demographic, self-cognitions and ED symptoms using logit and piecewise mixed effects modeling. Results: Attrition was highest during treatment phase but no significant predictors were found. During the measurement phase, the direction and amount of change in self-cognition interrelatedness and body dissatisfaction differed according to point of dropout and treatment group. Discussion: Attention to changes both in symptoms and mediating factors that occur during treatment and follow-up may help to identify those who are at risk for dropout and to develop strategies to promote RCT participant retention. © 2010 by Wiley Periodicals, Inc. (Int J Eat Disord 2011; 44:356–368)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83766/1/20800_ftp.pd