Thin film GaAs photovoltaic solar energy cells

Fabrication process for thin film gallium arsenide photovoltaic solar energy cell

Editorial: In use, in situ: extending field research methods

A case for evaluating in use and in-situ Many authors have argued the need for a broader understanding of context and the situatedness of activity when approaching the evaluation of systems. However, prevailing practice often still tends towards attempting to understand the use of designed artefacts by focusing on a core set of tasks that are thought to define the system. A consequence of such focus is that other tasks are considered peripheral and outside the scope of design and evaluation activities. To illustrate the point, consider the experience, familiar to many of us, of being involved in an evaluation activity where participants provide unstructured qualitative feedback. Irrespective of whether the activity is carried out in a laboratory, in a high fidelity simulation or in a naturalistic setting, participants will frequently volunteer unsolicited feedback about tasks and goals that were not originally within the ambit of the design activity. This unprompted feedback, we suggest, is a cue for the evaluators to pay attention to the relationship between the tool and the practice in which it will be used. In other words a cue to consider the situations in which artefact will be used, the tasks and activities that may be affected by the new system, and so on. These are empirical questions that cannot be answered a priori by the development team, whether the evaluation is taking place in “artificial” or “natural” setting

Thin-film GaAs photovoltaic solar energy cells Final report

Thin film gallium arsenide photovoltaic solar cell

Individual and Environmental Explanations for Violent Extremist Intentions: A German Nationally Representative Survey Study

This study examines individual differences in violent extremist intentions. It combines key criminological theories and concepts including situational action theory, social learning theory, self-control, general strain theory and legal cynicism. We employ a conceptually integrated approach to studying extremism, which acknowledges the profound effect of person-environment reciprocity and, thereby, we aim to identify key individual, developmental and social mechanisms involved in the development of extremist propensities. The analytical framework is tested using structural equation modeling. The analysis is based on a German nationally representative survey (N = 1502) collected via Computer Assisted Telephone Interviewing (CATI). Representativity of the sample was achieved via a systematic and controlled approach of a multi-stratified probability sample (random-digit-dialing) in the dual-frame mode (landline telephone- households and mobile phone users). Results highlight that low law-relevant morality, low self-control, and exposure to extremism-promoting settings are associated with individuals’ readiness to engage in violent extremism. The relationship between legal morality, self-control and violent extremism is further mediated by exposure to extremist peers. We thereby identify exposure to extremist settings as a key mechanism, which stresses the importance of including social environmental factors in the explanation of violent extremism. The proximate determinants are further related to a series of distal factors, such as perceived individual and collective strains and personal alienation

Assessing the relationship between terrorist attacks against ingroup or outgroup members and public support for terrorism

Terrorist groups rely on constituency support for their long-term survival. Here, we examined the extent to which terrorists’ own activities are related with public opinion on terrorism. Specifically, we assessed whether more frequent and more costly terrorist attacks against the ingroup are associated with war weariness or retaliatory sentiments, thus, either weaker or stronger approval of terrorism. We further investigated if more frequent and costly attacks that target an outgroup predict higher levels of justification of terrorism. Lastly, we identified the timeframe during which domestic and outgroup terrorist attacks correlate with (lower or higher) public support. The analyses focused on Jordan (ingroup) and Israel (outgroup), over an 8-year period (2004–2011), drawing on data from the Pew Global Attitudes Survey and the Global Terrorism Database. Results showed that support for terrorism in Jordan decreased in 2005 and, again, in 2008. The frequency of terrorist attacks and fatality/injury rates in Jordan did not vary significantly during the study period. The number of attacks and fatalities/people injured in Israel, however, changed between 2004 and 2011. Cross-correlations of the time-series further demonstrated that the number of attacks and fatalities/people injured in Jordan was not related with the level of public approval of terrorism in the country. Importantly, and in line with the literature, the casualty rate in Israel was positively associated with support for terrorism in Jordan, in the next year. That is, there is evidence that more/less costly terrorist attacks on an outgroup can predict stronger/weaker public support for the tactic relatively quickly. Those findings provide insights for counter-terrorism measures

EXPO-12: Development and validation of the Exposure to Violent Extremism Scale

Objective: This study details the development and validation of the 12-item Exposure to Violent Extremism Scale (EXPO-12). We aimed to undertake a transparent and robust process of scale development to present a tool to facilitate research on the relationship between exposure and violent extremism. / Method: First, we generated an initial item pool and evaluated items via expert feedback (n = 6) and a task designed to assess item comprehension (n = 13; Study 1). Second, we explored the underlying factor structure with exploratory factor analysis (EFA) and evaluated item characteristics with item response theory (IRT) in a representative sample of the U.K. population (n = 1, 509; Study 2). Finally, we sought to replicate the factor structure proposed by Study 2 via confirmatory factor analysis (CFA) and examined convergent validity with a related construct, violent extremist intentions (n = 1, 475; Study 3). / Results: Study 1 resulted in a preliminary pool of 40 items. Study 2 used EFA to establish a four-factor structure consisting of 21 items. IRT further reduced the item pool by evaluating differential item functioning, discrimination, and location parameters, resulting in EXPO-12. Study 3 replicated the factor structure proposed in Study 2 via CFA. EXPO-12 demonstrated good convergent validity with violent extremist intentions. / Conclusion: EXPO-12 is presented as a preliminarily validated measure of the concept, alongside its limitations. The scale’s main implication is as a tool to facilitate research to unpack the complexity and nuances of the relationship between exposure and violent extremism

Progress in thin film GaAs solar cells

Solar cells using polycrystalline films of gallium arsenid

Products of Random Matrices

We derive analytic expressions for infinite products of random 2x2 matrices. The determinant of the target matrix is log-normally distributed, whereas the remainder is a surprisingly complicated function of a parameter characterizing the norm of the matrix and a parameter characterizing its skewness. The distribution may have importance as an uncommitted prior in statistical image analysis.Comment: 9 pages, 1 figur