802 research outputs found
What’s in a Name? Unpacking Students’ Roles in Higher Education through Neoliberal and Social Justice Lenses
There has been an increase in research and practice exploring how students can gain agency to shape higher education experiences. Numerous terms evoking certain metaphors have entered the discussions around engaging students, from students as consumers or producers, to students as creators, partners, or change agents. There is scope within the evolving literature to explore the differentiations between these metaphors and how underlying assumptions ultimately shape our practices and research. We thus unpack the above five metaphors frequently used to redefine students’ roles in higher education. We then engage in a dialogue across differences: highlighting how our own two distinct perspectives on the research area and practice – grounded in neoliberalism and social justice – align, overlap, differ, and provide constraints or affordances for student engagement. We offer a critical and reflective commentary questioning the drivers of students’ changing roles in higher education in the hope of inviting others into generative dialogue toward expanding the evolving field of student engagement. </jats:p
Purchasing From Minority Small Businesses
This article employs a transaction costs framework to analyze the problems of Minority Business Enterprise (MBE) purchasing programs. The results from field surveys of small minority firms and corporate purchasing personnel indicate that program participants face differences in transaction costs and in their preferences of ways to overcome these costs. In the majority of situations, minority firms face higher transaction costs than do their corporate purchasing counterparts. The article offers recommendations for improving the performance of MBE purchasing programs, and the policy implications for these programs are discussed
The Value Orientations of Minority and Non-Minority Small Business Owners
This study examines value orientations of minority and non-minority small business owners and contrasts their perceived similarity with corporate customers. Six categories of organizational values, including the values of collectivism, duty, rationality, novelty, materialism, and power are examined. Analyses of a sample of 252 small business firms Indicate that minority owners differ from non-minority owners in their value orientations; and are significantly different from non-minority owners in the degree to which they perceive organizational value similarity with customers. However, the levels of perceived value similarity with corporate customers did not vary among the minority groups (i.e. blacks, Hispanics, Asians, and Native Americans). An implication is that value orientation may be an important component in the process of aligning the minority business firm with its environment. Further, a value system may be guiding the behavior of the minority small business owners against the overwhelming odds of racial/ethnic dissimilarities
Are You an Innovator or Adaptor? The Impact of Cognitive Propensity on Venture Expectations and Outcomes
In this study we confirm the often assumed but largely untested belief that entrepreneurs think and behave differently than others. We examine a group of more than 700 nascent entrepreneurs and 400 nonentrepreneurs. We determine the entrepreneurs’ cognitive style propensity for problem solving (Innovator versus Adaptor); we compare their expectations; and, we examine the outcomes (performance and start-up) of their ventures. We find that nascent entrepreneurs are more likely to be overly optimistic Innovators, most people are Adaptors, and one’s cognitive style can indeed play a role in the initial development and outcome for the venture, but not always as expected
Spin transmission control in helical magnetic fields
We calculate spin transport in two-dimensional waveguides in the presence of
spatially modulated Zeeman-split energy bands. We show that in a regime where
the spin evolution is predominantly adiabatic the spin backscattering rate can
be tuned via diabatic Landau-Zener transitions between the spin-split bands [C.
Betthausen et. al., Science 337, 324 (2012)]. This mechanism is tolerant
against spin-independent scattering processes. Completely spin-polarized
systems show full spin backscattering, and thus current switching. In partially
spin-polarized systems a spatial sequence of Landau-Zener transition points
enhances the resistance modulation via reoccupation of backscattered
spin-polarized transport modes. We discuss a possible application as a spin
transistor.Comment: Theory related to the adiabatic spin transistor concept (C.
Betthausen et al., Science 337, 324 (2012), DOI: 10.1126/science.1221350
Hydrogen analysis depth calibration by CORTEO Monte-Carlo simulation
Hydrogen imaging with sub-μm lateral resolution and sub-ppm sensitivity has become possible with coincident proton–proton (pp) scattering analysis (Reichart et al., 2004). Depth information is evaluated from the energy sum signal with respect to energy loss of both protons on their path through the sample. In first order, there is no angular dependence due to elastic scattering. In second order, a path length effect due to different energy loss on the paths of the protons causes an angular dependence of the energy sum. Therefore, the energy sum signal has to be de-convoluted depending on the matrix composition, i.e. mainly the atomic number Z, in order to get a depth calibrated hydrogen profile. Although the path effect can be calculated analytically in first order, multiple scattering effects lead to significant deviations in the depth profile. Hence, in our new approach, we use the CORTEO Monte-Carlo code (Schiettekatte, 2008) in order to calculate the depth of a coincidence event depending on the scattering angle. The code takes individual detector geometry into account. In this paper we show, that the code correctly reproduces measured pp-scattering energy spectra with roughness effects considered. With more than 100 μm thick Mylar-sandwich targets (Si, Fe, Ge) we demonstrate the deconvolution of the energy spectra on our current multistrip detector at the microprobe SNAKE at the Munich tandem accelerator lab. As a result, hydrogen profiles can be evaluated with an accuracy in depth of about 1% of the sample thickness
High-efficiency, single-stage 7-kHz high-average-power ultrafast laser system
Includes bibliographical references (page 467).We demonstrate a simple and practical single-stage ultrafast laser amplifier system that operates at a repetition frequency from 1 to 10 kHz, with millijoule pulse energy and as much as 13 W of average power. The repetition rate can be adjusted continuously from 1 to 10 kHz by new all-solid-state pump laser technology. This is to our knowledge the highest average power ever obtained from a single-stage ultrafast laser amplifier system. This laser will significantly increase the average power and the repetition rate that is easily accessible for high-field experiments such as coherent x-ray generation or for laser-synchrotron studies
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