Differential phase contrast in scanning optical microscopy

High-quality high-resolution transmission and reflection images produced using a scanning optical microscope and the split-detector technique are presented. These images exhibit differential phase contrast, the method avoiding some drawbacks of the usual Nomarski DIC arrangement. Imaging is treated theoretically and compared with the Nomarski method.     

Titanium dioxide for solar-hydrogen IV. Collective and local factors in photoreactivity

The mechanism of photo-reactivity between the TiO₂ surface and H₂O and the related charge transfer are considered in terms of the following two factors:

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The collective factor that is related to the collective macroscale properties, which are representative of the entire bulk phase or its surface layer as a continuum,     

Effects of higher-order driving skill training on young, inexperienced drivers' on-road driving performance

The aim of the current study was to compare the effects of training in higher-order driving skills (e.g., perceptual, motivational, insight) and vehicle handling skill training in relation to on-road driving performance, hazard perception, attitudes to risky driving and driver confidence levels in young, inexperienced drivers. Thirty-six young drivers (23 males and 13 females, average age 16.3 years), mostly on a restricted NZ driver licence, participated in a Driver Training Research camp. Participants were randomly allocated to one of three equally sized groups according to the type of driving skill training (5 days) they received: higher-order, vehicle handling or control (no training). Professional driver assessors conducted a comprehensive driving assessment before (Baseline) and after the training (Post Training). At both time points, participants also carried out a computerised hazard perception task, and completed self-report questionnaires to assess attitudes to risky driving and driver confidence. In terms of on road driving, the participants who received higher-order driving skill training showed a statistically significant improvement in relation to visual search and the composite driving measure. This was accompanied by an improvement in hazard perception, safer attitudes to close following and to dangerous overtaking and a decrease in driving related confidence. The participants who received vehicle handling skill training showed significant improvements in relation to their on-road direction control, speed choice and the composite driving score. However, this group showed no improvement in hazard perception, attitudes to risky driving or driver confidence. The findings will be discussed in the context of driver training as a viable crash prevention intervention in regard to young, inexperienced drivers.     

Partial polarization in three dimensions

Various different parameters have been introduced to describe the degree of polarization of a partially polarized electromagnetic field in three dimensions. Of these, parameters based on the eigenvalues of the coherency matrix are invariant under a unitary transformation. Here, explicit expressions are presented for the eigenvalues, thus providing a geometrical interpretation of the behavior. These expressions are applied to the Huynen decomposition and allow interrelations between different parameters to be developed.     

Effect of polarization on a solid immersion lens of arbitrary thickness

A solid immersion lens can be applied for high-resolution subsurface analysis of integrated circuits and other physical systems. We present a thorough analysis of the focal field distribution of a solid immersion lens system of arbitrary thickness. Cases of linearly and radially polarized illumination are examined and accurate expressions derived for the electric field in the image space. The effect of the spherical interface on both transverse and axial intensity profiles is analyzed. The performance and practicality of configurations deviating from the hemispherical and aplanatic cases are studied. The results show that optimal resolution is obtained at focal positions between the hemispherical and aplanatic points when radially polarized illumination is applied.     

Fluid chemistry of the waimangu geothermal system

The Waimangu geothermal area began discharging after the 1886 eruption of the Tarawera volcano, and currently consists of intense activity in the Waimangu and Lower Haumi Valleys, and on the western shore of the lake Rotomahana, with warm springs and seeps to the north and south. Variations in the chemical and isotopic compositions of water and gas discharges indicate that the deep water outflows near the lake, while large volumes of mixed origin, cooler waters are discharged in the Waimangu Valley. Large variations in the Cl : Cs, and apparent lack of mineral-solution equilibrium below 200°C indicate that the system has yet to arrive at a chemical equilibrium with the country rock at shallower levels. Cl : B and Cl : Cs ratios suggest a cogenetic relationship with geothermal systems to the south.     

Inline rheological behavior of dispersed water in a polyester matrix with a twin screw extruder

Solvent‐free extrusion emulsification (SFEE) is a complex process using twin‐screw extrusion to prepare solid‐liquid dispersions of high viscosity polymers and has received little study to date on its inherent mechanisms. To gain rheological insights into the earliest stage of SFEE as the interfacial boundary between water and polymer grows, prior to phase inversion, an inline orifice‐plate type viscometer is introduced to monitor transient behavior over a wide range of viscosities. The presented work examines rheological changes of a polyester‐water system produced by varying two factors thought to significantly control the final state of the dispersion, specifically polar group contributions to surface energy and viscosity. A processing modifier was combined with the polyester to study the influence of these two factors. The inline viscometer revealed an abrupt transition in viscosity occurred with the developed state of water dispersion, confirming observations of a prior batch study. Analysis of the rheological response indicated that a higher polar surface energy contribution had the greatest influence on the state of this transition, and that a steeper transition was related to greater incorporation of water within the polyester matrix. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers     

Signal-to-noise ratio in confocal microscope systems

The effects of various system parameters on the imaging performance of confocal microscopy are discussed, including the effects of pinhole size, type of detector and imaging algorithms on signal-to-noise ratio. Careful consideration of these parameters allows the microscope user to obtain the best performance for particular applications.     

The dynamics of innovation efforts in the early career

Although innovation is highly valued in organizations, early-career professionals face a paradox of bringing in novel ideas, yet having varied latitude and support to see these new ideas through. Building on 35 critical-incident-based interviews with early-career engineers in the United States, this study illuminates the socially situated dynamics of their innovation efforts, examining the process of such promotive proactive behaviour. We find that all participants reported some engagement in creating, championing and implementing new ideas, typically in the form of self-initiated improvements to the tools and processes participants used in their jobs. Encouragement from direct supervisors, supportive organizational cultures and practices, job scope, time afforded and one's perceived status were key considerations in determining whether to take such initiative. Carrying out innovative work behaviours, in turn, was largely dependent on continued employee initiative and ad hoc, informal cooperation, with individual effort punctuated by influential interactions with others that often determined the perceived valence of efforts. The study adds to understanding the social interactions and perceptions of voice required for innovative work behaviour, revealing when and to whom these prerequisites are afforded. Implications for organizations' innovation capacity and new hires' participation in innovation are discussed.