Supercapacitors based on pillared graphene nanostructures

We describe the fabrication of highly conductive and large-area three dimensional pillared graphene nanostructure (PGN) films from assembly of vertically aligned CNT pillars on flexible copper foils for applications in electric double layer capacitors (EDLC). The PGN films synthesized via a one-step chemical vapor deposition process on flexible copper foils exhibit high conductivity with sheet resistance as low as 1.6 ohms per square and possessing high mechanical flexibility. Raman spectroscopy indicates the presence of multi walled carbon nanotubes (MWCNT) and their morphology can be controlled by the growth conditions. It was discovered that nitric acid treatment can significantly increase the specific capacitance of the devices. EDLC devices based on PGN electrodes (surface area of 565 m2/g) demonstrate enhanced performance with specific capacitance value as high as 330 F/g extracted from the current density-voltage (CV) measurements and energy density value of 45.8 Wh/kg. The hybrid graphene-CNT nanostructures are attractive for applications including supercapacitors, fuel cells and batteries.     

Precision engineering for future propulsion and power systems: a perspective from Rolls-Royce

Rolls-Royce today is an increasingly global business, supplying integrated power systems to a wide variety of customers for use on land, at sea and in the air. Its reputation for 'delivering excellence' to these customers has been built largely on its gas turbine technology portfolio, and this reputation relies on the quality of the company's expertise in design, manufacture and delivery of services. This paper sets out to examine a number of examples, such as the high-pressure turbine blade, of the company's reliance on precision design and manufacture, highlighting how this precision contributes to customer satisfaction with its products. A number of measures the company is taking to accelerate its competitiveness in precision manufacture are highlighted, not least its extensive relationships with the academic research base. The paper finishes by looking briefly at the demands of the company's potential future product portfolio.     

Simulation-optimization of solar-thermal refrigeration systems for office use in subtropical Hong Kong

The solar-thermal refrigeration systems, covering the solar absorption refrigeration system (SAbRS) and the solar adsorption refrigeration system (SAdRS), were designed for typical office in the subtropical Hong Kong. The approach of simulation-optimization was adopted in order to determine the optimal design parameters for SAbRS and SAdRS against the conventional design practice. For simulation, dynamic model of each system was refined on the TRNSYS platform. For optimization, the objective was to minimize the annual primary energy consumption of SAbRS or SAdRS in response to the changing loading and climatic conditions throughout a year. This is a constrained optimization problem since the upper limit of comfort temperature was stipulated, such that the minimization of system energy would not sacrifice the indoor thermal comfort. Due to the complex, multidimensional and constrained nature of the dynamic simulation models, the differential evolution (DE), which has been proven effective in evolutionary computation (EC), was used for optimization purpose. Through the simulation-optimization run, the optimized designs of SAbRS and SAdRS were determined, and their corresponding primary energy consumptions could be 12.2% and 7.1% less than those based on the general design practice. The results provide useful guidelines for the equipment design of SAbRS and SAdRS.     

Perceiving others’ personalities: Examining the dimensionality, assumed similarity to the self, and stability of perceiver effects.

In interpersonal perception, “perceiver effects” are tendencies of perceivers to see other people in a particular way. Two studies of naturalistic interactions examined perceiver effects for personality traits: seeing a typical other as sympathetic or quarrelsome, responsible or careless, and so forth. Several basic questions were addressed. First, are perceiver effects organized as a global evaluative halo, or do perceptions of different traits vary in distinct ways? Second, does assumed similarity (as evidenced by self-perceiver correlations) reflect broad evaluative consistency or trait-specific content? Third, are perceiver effects a manifestation of stable beliefs about the generalized other, or do they form in specific contexts as group-specific stereotypes? Findings indicated that perceiver effects were better described by a differentiated, multidimensional structure with both trait-specific content and a higher order global evaluation factor. Assumed similarity was at least partially attributable to trait-specific content, not just to broad evaluative similarity between self and others. Perceiver effects were correlated with gender and attachment style, but in newly formed groups, they became more stable over time, suggesting that they grew dynamically as group stereotypes. Implications for the interpretation of perceiver effects and for research on personality assessment and psychopathology are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using maintenance rehearsal to explore recognition memory.

We examined associative and item recognition using the maintenance rehearsal paradigm. Our intent was to control for mnemonic strategies; to produce a low, graded level of learning; and to provide evidence of the role of attention in long-term memory. An advantage for low-frequency words emerged in both associative and item recognition at very low levels of learning. This early emergence casts doubt on explanations based on the traditional concept of recollection. A comparison of false alarms supports a role for item information or the joint use of cues but not familiarity in producing associative false alarms. We may also have found a way to measure the amount of attention being paid to a to-be-learned item or pair, independently of memory performance on the attended item. This result may be an important step in determining whether coherent theories about the role of attention in long- and short-term memory can be created. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Climbing the stairway to competency: Trainee perspectives on competency development.

Training programs have increasingly focused on development of competencies as a benchmark for trainee progress. While much writing on the subject of trainee competency has focused on programmatic implementation of competency-based training, considerably less attention has been paid to the experience of trainees in these programs. The current study sampled a cross-section of 641 graduate students enrolled in member doctoral programs of the Council of University Directors of Clinical Psychology. These students were divided into four groups based on stage of training and reported on their development of core competencies. Overall, students entered doctoral programs reporting high levels of adaptive trainee characteristics and felt competent in a range of areas by the time they applied for internship. Competencies in research, assessment, and intervention developed over the course of graduate training. Reported competency in research was higher for trainees endorsing a goal of a research career, while reported competency in empathy and therapeutic relationships was higher for trainees endorsing a goal of clinical practice. Findings are discussed in the context of implementing competency assessment that encompasses the ratings of trainees as well as supervisors and programs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dynamic processes of domain switching in lead zirconate titanate under cyclic mechanical loading by in situ neutron diffraction

The performance of ferroelectric ceramics is governed by the ability of domains to switch. A decrease in the switching ability can lead to degradation of the materials and failure of ferroelectric devices. In this work the dynamic properties of domain reorientation are studied. In situ time-of-flight neutron diffraction is used to probe the evolution of ferroelastic domain texture under mechanical cyclic loading in bulk lead zirconate titanate ceramics. The high sensitivity of neutron diffraction to lattice strain is exploited to precisely analyze the change of domain texture and strain through a full-pattern Rietveld method. These results are then used to construct a viscoelastic model, which explains the correlation between macroscopic phenomena (i.e. creep and recovered deformation) and microscopic dynamic behavior (i.e. ferroelastic switching, lattice strain).     

Older female drivers: An emerging transport safety and mobility issue in Australia

This paper describes an investigation of safety, mobility and travel patterns in a sample of older women drivers and former drivers aged 60 years and over. Participants provided information on general health and functional abilities, travel and driving patterns, driving experiences and confidence, difficulty with and avoidance of driving situations, self-assessment of driving ability, crash and infringement history, the process and experiences leading up to stopping driving, and satisfaction with current mobility. The sample was a fairly active group, travelling frequently and substantial distances, and generally satisfied with their level of mobility. Current drivers were strongly interested in keeping driving for as long as possible, expressed strong concerns about the prospect of stopping driving and reported little evidence of self-regulation. In contrast, former drivers were less negative about driving cessation and mostly reported successful retirement from driving with few negative mobility consequences. Further, a number of relationships between crash involvement and driving experience, confidence of being a safe driver, and problems in driving situations were found. These findings have added to our understanding of the issues concerning the safety and mobility of older women. Implications for the promotion of safe driving practices are discussed.