A comparison of labor mobility in the Soviet Union and the United States

Call number: LD2668 .R4 1968 L42

Characterization of Metal and Metal Alloy Films as Contact Materials in MEMS Switches

This study presents a basic step toward the selection methodology of electric contact materials for microelectromechanical systems (MEMS) metal contact switches. This involves the interrelationship between two important parameters, resistivity and hardness, since they provide the guidelines and assessment of contact resistance, wear, deformation and adhesion characteristics of MEMS switches. For this purpose, thin film alloys of three noble metals, platinum (Pt), rhodium (Rh) and ruthenium (Ru) with gold (Au), were investigated. The interrelationship between resistivity and hardness was established for three levels of alloying of these metals with gold. Thin films of gold (Au), platinum (Pt), ruthenium (Rh) and rhodium (Ru) were also characterized to obtain their baseline data for comparison. All films were deposited on silicon substrates. When Ru, Rh and Pt are alloyed with Au, their hardness generally decreases but resistivity increases. This decrease or increase was, in general, dependent upon the amount of alloying

Selecting Metal Alloy Electric Contact Materials for MEMS Switches

This paper presents a method for selecting metal alloys as the electric contact materials for microelectromechanical systems (MEMS) metal contact switches. This procedure consists of reviewing macro-switch lessons learned, utilizing equilibrium binary alloy phase diagrams, obtaining thin film material properties and, based on a suitable model, predicting contact resistance performance. After determining a candidate alloy material, MEMS switches were designed, fabricated and tested to validate the alloy selection methodology. Minimum average contact resistance values of 1.17 and 1.87 Ω were measured for micro-switches with gold (Au) and gold–platinum (Au–(6.3%)Pt) alloy electric contacts, respectively. In addition, \u27hot-switched\u27 life cycle test results of 1.02 × 108 and 2.70 × 108 cycles were collected for micro-switches with Au and Au–(6.3%)Pt contacts, respectively. These results indicate increased wear with a small increase in contact resistance for MEMS switches with metal alloy electric contacts

Radio Frequency MEMS Switch Contact Metal Selection

A method for selecting metal alloys as the electric contact materials for microelectromechanical systems (MEMS) metal contact switches. This method includes a review of alloy experience, consideration of equilibrium binary alloy phase diagrams, obtaining thin film material properties and, based on a suitable model, predicting contact electrical resistance performance. After determination of a candidate alloy material, MEMS switches are conceptualized, fabricated and tested to validate the alloy selection methodology. Minimum average contact resistance values of 1.17 and 1.87 ohms are achieved for micro-switches with gold (Au) and gold-platinum (Au-(6.3 at %)Pt) alloy contacts. In addition, `hot-switched` life cycle test results of 1.02.x108 and 2.70.x108 cycles may be realized for micro-switches with Au and Au-(6.3 at %)Pt contacts. These results indicate increased wear with a small increase in contact resistance for MEMS switches with metal alloy electric contacts

The representation of scientific research in the national curriculum and secondary school pupils’ perceptions of research, its function, usefulness and value to their lives

Young people’s views on what research is, how it is conducted and whether it is important, influences the decisions they make about their further studies and career choices. In this paper we report the analysis of questionnaire data with a particular focus on pupil perceptions of research in the sciences and of the scientific method. The questionnaire was a 25-item Likert Scale (1-5) distributed to seven collaborating schools. We received 2634 returns from pupils across key stages 3, 4 and 5. We also asked teachers to complete the questionnaire in order to explore how they thought their pupils would respond. We received 54 teacher responses. Statistically significant differences in the responses were identified through a chi-square test on SPSS. As what is being taught influences secondary pupil views on research we also consider how the term ‘research’ appears in the national curriculum for England and Wales and the three main English exam boards. The main theoretical construct that informs our analysis of the questionnaire data and the national curriculum is Angela Brew’s 4-tier descriptor of perceptions of research (domino, trading, layer, journey). We use this framework in order to map what, when and how research is presented to school pupils in England and Wales. We also use this framework in order to highlight and discuss certain pupil views that emerged from the questionnaire data and which indicate areas where curriculum and pedagogy intervention may be necessary: pupils seem less confident in their understanding of research as involving the identification of a research question; and, they often see research as a means to confirm one’s own opinion. They do however understand research as involving the generation of new knowledge and the collection of new data, such as interviews and questionnaires as well as laboratory work, field trips and library searches and they appear relatively confident in their statements about their ability to do research, their school experiences of research and the importance of research in their future career choice

Self-compensation in semiconductors: The Zn vacancy in Ga-doped ZnO

Self-compensation, the tendency of a crystal to lower its energy by forming point defects to counter the effects of a dopant, is here quantitatively proven. Based on a new theoretical formalism and several different experimental techniques, we demonstrate that the addition of 1.4 × 10 exp 21-cm exp −3 Ga donors in ZnO causes the lattice to form 1.7 × 10 exp 20-cm exp −3 Zn-vacancy acceptors. The calculated VZn formation energy of 0.2 eV is consistent with predictions from density functional theory. Our formalism is of general validity and can be used to investigate self-compensation in any degenerate semiconductor material.Peer reviewe

BIG-DATA and the Challenges for Statistical Inference and Economics Teaching and Learning

The  increasing  automation  in  data  collection,  either  in  structured  orunstructured formats, as well as the development of reading, concatenation and comparison algorithms and the growing analytical skills which characterize the era of Big Data, cannot not only be considered a technological achievement, but an organizational, methodological and analytical challenge for knowledge as well, which is necessary to generate opportunities and added value.In fact, exploiting the potential of Big-Data includes all fields of community activity; and given its ability to extract behaviour patterns, we are interested in the challenges for the field of teaching and learning, particularly in the field of statistical inference and economic theory.Big-Data can improve the understanding of concepts, models and techniques used in both statistical inference and economic theory, and it can also generate reliable and robust short and long term predictions. These facts have led to the demand for analytical capabilities, which in turn encourages teachers and students to demand access to massive information produced by individuals, companies and public and private organizations in their transactions and inter- relationships.Mass data (Big Data) is changing the way people access, understand and organize knowledge, which in turn is causing a shift in the approach to statistics and economics teaching, considering them as a real way of thinking rather than just operational and technical disciplines. Hence, the question is how teachers can use automated collection and analytical skills to their advantage when teaching statistics and economics; and whether it will lead to a change in what is taught and how it is taught.Peñaloza Figueroa, J.; Vargas Perez, C. (2017). BIG-DATA and the Challenges for Statistical Inference and Economics Teaching and Learning. Multidisciplinary Journal for Education, Social and Technological Sciences. 4(1):64-87. doi:10.4995/muse.2017.6350.SWORD648741Akerkar R. (Ed.). (2014). Big Data Computing. CRC Press.Anderson, C. (2009). "Living by Numbers". Wired Magazine. July 2009.New York: Conde Nast Publications.Cukier, Kenneth and Mayer-Schönberger, Viktor (2013). Big Data: A Revolution that Will Transform How We Live, Work and Think. John Murray Publishers. London, UK.Dean, J., & Ghemawat, S. (2008). MapReduce. Communications of the ACM, 51(1), 107. doi:10.1145/1327452.1327492Diebold, F. X. (2012). A Personal Perspective on the Origin(s) and Development of «Big Data»: The Phenomenon, the Term, and the Discipline, Second Version. SSRN Electronic Journal. doi:10.2139/ssrn.2202843Duboc, L., Rosenblum, D. S., & Wicks, T. (2006). A framework for modelling and analysis of software systems scalability. Proceeding of the 28th international conference on Software engineering - ICSE ’06. doi:10.1145/1134285.1134460García Ros, R., Pérez González, F. & Talaya González, I. (2008). Preferencias Respecto a Métodos Instruccionales de los Estudiantes Universitarios de Nuevo Acceso y su Relación con Estilos de Aprendizaje y Estrategias Motivacionales. Electronic Journal of Research in Educational Psychology, 6(16), 547-570.Gould, R. (2010). Statistics and the Modern Student. International Statistical Review, 78(2), 297-315. doi:10.1111/j.1751-5823.2010.00117.xKambatla, K., Kollias, G., Kumar, V., & Grama, A. (2014). Trends in big data analytics. Journal of Parallel and Distributed Computing, 74(7), 2561-2573. doi:10.1016/j.jpdc.2014.01.003Leedy, P. & Ormrod, J. (2001). Practical Research: Planning and Design. 7th Editon. Upper Saddle River, NJ: Merrill Prentice Hall. Thousand Oaks: SAGE Publications.Meyer-Schonberger, Viktor and Cukier, Kenneth (2013). Big Data: A Revolution that Will Transform How We Live, Work and Think. John Murray Publishers. London. UK Company.Müller, Martin U., Rosenbach, Marcel and Schulz, Thomas (2013). Living by Numbers: Big-Data Knows What your Future Holds. DER SPIEGEL No. 20. Germany (Translated from German by Christopher Sultan).Pe-a, D., Prieto, J. and Viladomat, J. (2010) "Eigenvectors of a Kurtosis Matrix as Interesting Directions to Reveal Cluster Structure", Journal of Multivariate Analysis 9, 1995 -2007, 2010. https://doi.org/10.4995/muse.2015.2245Peñaloza Figueroa, J. L., & Vargas Perez, C. (2014). Construction and Evaluation of Scenarios as a Learning Strategy through Modelling-Simulation. Multidisciplinary Journal for Education, Social and Technological Sciences, 2(1), 40. doi:10.4995/muse.2015.2245Zhang, J., Wang, F.-Y., Wang, K., Lin, W.-H., Xu, X., & Chen, C. (2011). Data-Driven Intelligent Transportation Systems: A Survey. IEEE Transactions on Intelligent Transportation Systems, 12(4), 1624-1639. doi:10.1109/tits.2011.215800

Ceding to their appetites: A taxonomy of international tourists to South Africa

Tourism is a key source of income to South Africa. Food and beverages is a key part of tourism and the literature reveals that tourists spend up to a quarter of their budget on cuisine. South Africa has, however, been rated as the least-prepared culinary travel destination and the travel destination with the greatest potential for growth. Therefore, a segmentation taxonomy based on culinary preferences of international tourists to South Africa is put forth which can be used to prepare South Africa as a culinary travel destination. The 627 international tourists surveyed were divided into five segments with the use of factor analyses, t-tests, Spearman rank correlations and analysis of variance. The segments were named conservationists, experience seekers, devotees, explorers and socialisers (CEDES taxonomy). Multiple results and implications are discussed in the paper

Thin channel β-Ga2O3 MOSFETs with self-aligned refractory metal gates

We report the first demonstration of self-aligned gate (SAG) β-Ga2O3 metal-oxide-semiconductor field-effect transistors (MOSFETs) as a path toward eliminating source access resistance for low-loss power applications. The SAG process is implemented with a subtractively defined and etched refractory metal, such as Tungsten, combined with ion-implantation. We report experimental and modeled DC performance of a representative SAG device that achieved a maximum transconductance of 35 mS mm-1 and an on-resistance of ∼30 Ω mm with a 2.5 μm gate length. These results highlight the advantage of implant technology for SAG β-Ga2O3 MOSFETs enabling future power switching and RF devices with low parasitic resistance. © Not subject to copyright in the USA. Contribution of Wright-Patterson AFB

'Working out’ identity: distance runners and the management of disrupted identity

This article contributes fresh perspectives to the empirical literature on the sociology of the body, and of leisure and identity, by analysing the impact of long-term injury on the identities of two amateur but serious middle/long-distance runners. Employing a symbolic interactionist framework,and utilising data derived from a collaborative autoethnographic project, it explores the role of ‘identity work’ in providing continuity of identity during the liminality of long-term injury and rehabilitation, which poses a fundamental challenge to athletic identity. Specifically, the analysis applies Snow and Anderson’s (1995) and Perinbanayagam’s (2000) theoretical conceptualisations in order to examine the various forms of identity work undertaken by the injured participants, along the dimensions of materialistic, associative and vocabularic identifications. Such identity work was found to be crucial in sustaining a credible sporting identity in the face of disruption to the running self, and in generating momentum towards the goal of restitution to full running fitness and reengagement with a cherished form of leisure. KEYWORDS: identity work, symbolic interactionism, distance running, disrupted identit