61 research outputs found

    Polymer Dissolution Model: An Energy Adaptation Of The Critical Ionization Theory

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    The current scale of features size in the microelectronics industry has reached the point where molecular level interactions affect process fidelity and produce excursions from the continuum world like line edge roughness (LER). Here we present a 3D molecular level model based on the adaptation of the critical ionization (CI) theory using a fundamental interaction energy approach. The model asserts that it is the favorable interaction between the ionized part of the polymer and the developer solution which renders the polymer soluble. Dynamic Monte Carlo methods were used in the current model to study the polymer dissolution phenomenon. The surface ionization was captured by employing an electric double layer at the interface, and polymer motion was simulated using the Metropolis algorithm. The approximated interaction parameters, for different species in the system, were obtained experimentally and used to calibrate the simulated dissolution rate response to polymer molecular weight and developer concentration. The predicted response is in good agreement with experimental dissolution rate data. The simulation results support the premise of the CI theory and provide an insight into the CI model from a new prospective. This model may provide a means to study the contribution of development to LER and other related defects based on molecular level interactions between distinct components in the polymer and the developer.Chemical Engineerin

    Evaluation of marking of peer marking in oral presentation.

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    BACKGROUND: Peer marking is an important skill for students, helping them to understand the process of learning and assessment. This method is increasingly used in medical education, particularly in formative assessment. However, the use of peer marking in summative assessment is not widely adopted because many teachers are concerned about biased marking by students of their peers. OBJECTIVE: The aim of this study was to investigate whether marking of summative peer assessment can improve the reliability of peer marking. METHODS: In a retrospective analysis, the peer-marking results of a summative assessment of oral presentations of two cohorts of students were compared. One group of students was told that their peer marks would be assessed against a benchmark consisting of the average of examiner marks and that these scores together with the peer and examiner marks would form their final exam results. The other group of students were just informed that their final exam results would be determined based on the examiner and peer marks. RESULTS: Based on examiner marks, both groups of students performed similarly in their summative assessment, agreement between student markers was less consistent and more polar than the examiners. When compared with the examiners, students who were told that their peer marking would be scored were more generous markers (their average peer mark was 2.4 % points higher than the average examiner mark) while students who were not being scored on their marking were rather harsh markers (their average peer mark was 4.2 % points lower than the average examiner mark), with scoring of the top-performing students most affected. CONCLUSIONS: Marking of peer marking had a small effect on the marking conduct of students in summative assessment of oral presentation but possibly indicated a more balanced marking performance

    Classroom Ventilation: The Effectiveness of Preheating and Refresh Breaks: An analysis of 169 spaces at 43 schools across New Zealand

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    The COVID-19 pandemic has highlighted the importance of ventilation as a transmission mitigation strategy. However, there was a widely held concern that a drop in outdoor temperatures during winter may impact thermal comfort in the context of naturally ventilated classrooms. This concern has not been widely investigated by peer-reviewed empirical studies (Sutherland et al., 2022b). The aim of the Ministry’s ventilation monitoring initiative was to assess ventilation performance and thermal comfort by continuously measuring indoor CO2 levels, air temperature, and relative humidity in classrooms during winter, without obstructing teaching activities. A total of 43 schools, which represent a broad mix of property attributes and located across the 6 Climate Zones in New Zealand, were selected for the monitoring initiative. The CO2 monitors were deployed in about 4-6 pre-selected and representative spaces in each school. Data was retrieved from 213 spaces; of these, 44 spaces were excluded, because the initiative concentrated on teaching environments (classrooms) and those spaces were categorised as non-teaching environments (e.g., staff rooms, meeting rooms, etc.). From the 213 spaces, the data from 169 teaching spaces retrieved for the period 23 May to 26 August 2022 were analysed to ascertain the impacts of inferred human behaviours considered to be able to improve natural ventilation and detected from features of CO2 and temperature data. This analysis does not (and did not intend to) corroborate independent observation of behaviours

    Depressive Symptoms, Gender, and Growth in Cigarette Smoking among Indigenous Adolescents

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    This study reports findings from two-level growth curve modeling of cigarette smoking and depressive symptoms based on the first three waves of data from a longitudinal study of Indigenous adolescents and their parents/caretakers in the northern Midwest and Canada. The 743 adolescents were aged 10–13 years at Wave 1 and 12–15 years at Wave 3. Over the three years of the study the overall retention rate was 93%. By Wave 3, 39% of the adolescent girls and 25% of the boys had smoked cigarettes in the past 12 months. The growth curve results indicated that smoking increased for both adolescent boys and girls across time. Depressive symptoms were associated with an increase in cigarette smoking for girls but not boys

    Schizophrenia and psychotic symptoms in families of two American Indian tribes

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    Abstract Background The risk of schizophrenia is thought to be higher in population isolates that have recently been exposed to major and accelerated cultural change, accompanied by ensuing socio-environmental stressors/triggers, than in dominant, mainstream societies. We investigated the prevalence and phenomenology of schizophrenia in 329 females and 253 males of a Southwestern American Indian tribe, and in 194 females and 137 males of a Plains American Indian tribe. These tribal groups were evaluated as part of a broader program of gene-environment investigations of alcoholism and other psychiatric disorders. Methods Semi-structured psychiatric interviews were conducted to allow diagnoses utilizing standardized psychiatric diagnostic criteria, and to limit cultural biases. Study participants were recruited from the community on the basis of membership in pedigrees, and not by convenience. After independent raters evaluated the interviews blindly, DSM-III-R diagnoses were assigned by a consensus of experts well-versed in the local cultures. Results Five of the 582 Southwestern American Indian respondents (prevalence = 8.6 per 1000), and one of the 331 interviewed Plains American Indians (prevalence = 3.02 per 1000) had a lifetime diagnosis of schizophrenia. The lifetime prevalence rates of schizophrenia within these two distinct American Indian tribal groups is consistent with lifetime expectancy rates reported for the general United States population and most isolate and homogeneous populations for which prevalence rates of schizophrenia are available. While we were unable to factor in the potential modifying effect that mortality rates of schizophrenia-suffering tribal members may have had on the overall tribal rates, the incidence of schizophrenia among the living was well within the normative range. Conclusion The occurrence of schizophrenia among members of these two tribal population groups is consistent with prevalence rates reported for population isolates and in the general population. Vulnerabilities to early onset alcohol and drug use disorders do not lend convincing support to a diathesis-stressor model with these stressors, commonly reported with these tribes. Nearly one-fifth of the respondents reported experiencing psychotic-like symptoms, reaffirming the need to examine sociocultural factors actively before making positive diagnoses of psychosis or schizophrenia.</p
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