235 research outputs found
Comparative study of Cl₂, Cl₂/O₂, and Cl₂/N₂ inductively coupled plasma processes for etching of high-aspect-ratio photonic-crystal holes in InP
An extensive investigation has been performed on inductively coupled plasmaetching of InP. An important motivation for this work is the fabrication of high-aspect-ratio holes for photonic crystals. The essential chemistry is based on Cl₂ with the addition of N₂ or O₂ for sidewall passivation. The influence of different process parameters such as gas flows, temperature,pressure, ion energy, and inductively coupled plasma power on the hole geometry is presented. It is concluded that photonic crystals can be etched with Cl₂ only; however, temperature and pressure control is critical. Adding passivation gases largely broadens the window in the parameter space for hole etching. Most importantly, etching of narrow holes can be carried out at higher temperatures where the etching is mass limited and spontaneous etching of InP by Cl₂ occurs.Part of this research is supported by NanoNed, a technology program of the Dutch
Ministry of Economic Affairs
Report of Climate Sub Group 2004 Climate Sub-group
Attachment theory implies the causal influence of interpretation bias on the attachment-related expectations. Previous research demonstrated that training children to interpret maternal behavior as more supportive increased their trust in maternal support. The current study explored possible training effects on two attachment script-related processes: recollection of attachment-related memories and secure base script knowledge. Children (9–12 years old; N = 84) were assigned to either a secure training condition, training children to interpret mother's behavior as supportive, or a neutral placebo condition, where interpretations about maternal behavior were unrelated to support. Findings replicated the training effect on interpretation bias and trust. Furthermore, children's recollection of attachment-related memories became more positive. No training effect was found for secure base script knowledg
Modifying Threat-related Interpretive Bias in Adolescents
Socially anxious feelings sharply increase during adolescence and such feelings have been associated with interpretive biases. Studies in adults have shown that interpretive biases can be modified using Cognitive Bias Modification procedures (CBM-I) and subsequent effects on anxiety have been observed. The current study was designed to examine whether the CBM-I procedure has similar effects in adolescents. Unselected adolescents were randomly allocated to either a positive interpretation training (n = 88) or a placebo-control condition (n = 82). Results revealed that the training was successful in modifying interpretations and effects generalized to a new task. The interpretive bias effects were most pronounced in individuals with a threat-related interpretive bias at pre-test. No effects on state anxiety were observed. The current findings are promising with regard to applying bias modification procedures to adolescents, while further research is warranted regarding emotional effects
A guided, internet-based stress management intervention for university students with high levels of stress:Feasibility and acceptability study
BackgroundTransitioning to adulthood and challenges in university life can result in increased stress levels among university students. Chronic and severe stress is associated with deleterious psychological and physiological effects. Digital interventions could succeed in approaching and helping university students who might be at risk; however, the experiences of students with internet-based stress management interventions are insufficiently understood.ObjectiveThis study aims to explore the feasibility; acceptability; and changes in perceived stress, depressive symptoms, and quality of life from baseline to posttest assessment of a 5-session, internet-based stress management intervention guided by an e-coach, developed for university students experiencing high levels of stress.MethodsA single-arm study was conducted. Students were recruited from different channels, mainly from a web survey. Students were eligible if they (1) scored ≥20 on the Perceived Stress Scale-10, (2) were aged ≥18 years, and (3) were studying at one of the participating universities. Feasibility and acceptability of the intervention were investigated using several indications, including satisfaction (Client Satisfaction Questionnaire-8) and usability (System Usability Scale-10). We also investigated the indicators of intervention adherence using use metrics (eg, the number of completed sessions). Our secondary goal was to explore the changes in perceived stress (Perceived Stress Scale-10), depressive symptoms (Patient Health Questionnaire-9), and quality of life (EQ-5D-5L scale) from baseline to posttest assessment. In addition, we conducted semistructured interviews with intervention completers and noncompleters to understand user experiences in depth. For all primary outcomes, descriptive statistics were calculated. Changes from baseline to posttest assessment were examined using 2-tailed paired sample t tests or the Wilcoxon signed rank test. Qualitative data were analyzed using thematic analysis.ResultsOf 436 eligible students, 307 (70.4%) students started using the intervention. Overall, 25.7% (79/307) completed the core sessions (ie, sessions 1-3) and posttest assessment. A substantial proportion of the students (228/307, 74.3%) did not complete the core sessions or the posttest assessment. Students who completed the core sessions reported high satisfaction (mean 25.78, SD 3.30) and high usability of the intervention (mean 86.01, SD 10.25). Moreover, this group showed large reductions in perceived stress (Cohen d=0.80) and moderate improvements in depression score (Cohen d=0.47) and quality of life (Cohen d=-0.35) from baseline to posttest assessment. Qualitative findings highlight that several personal and intervention-related factors play a role in user experience.ConclusionsThe internet-based stress management intervention seems to be feasible, acceptable, and possibly effective for some university students with elevated stress levels. However, given the high dropout rate and qualitative findings, several adjustments in the content and features of the intervention are needed to maximize the user experience and the impact of the intervention.Trial Registration: Netherlands Trial Register 8686; https://onderzoekmetmensen.nl/nl/trial/20889.International Registered Report Identifier (IRRID): RR2-10.1016/j.invent.2021.100369.</p
Scanning Tunneling Microscope-Induced Luminescence Spectroscopy on Semiconductor Heterostructures
Scanning tunneling microscope (STM)-induced luminescence is explored as a technique for the characterization of semiconductor quantum wells and quantum wire heterostructures. By injecting minority carriers into the cleaved cross section of these structures, luminescence excitation on a nanometer scale is demonstrated. Using spectrally resolved STM-induced luminescence for the tip placed at various positions across the cleaved heterostructure, it is possible to obtain local spectroscopic information on closely spaced quantum structures
This Other Eden: Exploring a Sense of Place in Twentieth-Century Reconstructions of Australian Childhoods
This thesis explores the sense of place formed during childhood, as remembered by adult Australians who reconstruct their youth through various forms of life writing. While Australian writers do utilize traditional tropes of Western autobiography, such as the mythology of Eden and the Wordsworthian image of the child communing with Nature, these themes are frequently transformed to meet a uniquely Australian context. Isolation and distance from Europe, and the apparent indifference of our landscape towards white settlement, have received much critical attention in Australian studies generally and, indeed, broadly influence the formation of children’s sense of place across the continent. However, writers are also concerned with the role of place on a more local level. Through a comparison of writing from Western Australia, Queensland and Victoria, this thesis explores regional landscape preoccupations that create an awareness of local identity, variously contributing to or frustrating the child’s sense of belonging. Western Australian writing is dominated by images of isolation, the fragility of white settlement in a dry land lacking fresh water, and a pervasive beach culture. A strong sense of the littoral pervades writing from this region. Queensland’s frontier mythology is of a different flavour: warm and tropical, nature here is exuberant, constantly threatening to overwhelm culture, already perceived as transient due to the flimsy aspect of the “Queenslander” house. Writing from Victoria, to some extent, tends to more closely follow English models, juxtaposing country and city environments, although there is a distinctly local flavour to many representations of urban Melbourne and its flat, grid-like organization. As Australian society becomes more concentrated on the coastal fringe, the beach is an increasingly significant environment. Though more prominent in writing from some regions than others, coastal imagery broadly reflects the modern Australian’s sense of inhabiting a liminal zone with negotiable boundaries
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