Photovoltaic effect of tin disulfide with nanocrystalline/amorphous blended phases

Tin disulfide (SnS2) nanocrystalline/amorphous blended phases were synthesized by mild chemical reaction. Both X-ray diffraction and transmission electron microscopy measurements demonstrate that the as-synthesized particles presented very small size, with a diameter of only a few nanometers. The photoluminescence (PL) spectrum suggests efficient splitting of photo-generated excitons in poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) and SnS2 hybrid films. Organic/inorganic hybrid solar cells comprising MDMO-PPV and SnS2 were prepared, giving photovoltage, photocurrent, fill factor and efficiency values of 0.702 V, 0.549 mA/cm(2), 0.385 and 0.148%, respectively, which suggests that this phase-blended inorganic semiconductor can also serve as a promising solar energy material. (C) 2009 Elsevier Ltd. All rights reserved.

Miscibility and crystallization behavior of solution-blended PEEK/PI blends

Miscibility and crystallization behavior of solution-blended poly(ether ether ketone)/polyimide (PEEK/PI) blends were investigated by using DSC, optical microscopy and SAXS methods. Two kinds of PIs, YS-30 and PEI-E, which consist of the same diamine but different dianhydrides, were used in this work. The experimental results show that blends of PEEK/YS-30 are miscible over the entire composition range, as all the blends of different compositions exhibit a single glass transition temperature. The crystallization of PEEK was hindered by YS-30 in PEEK/YS-30 blends, of which the dominant morphology is interlamellar. On the other hand, blends of PEEK/PEI-E are immiscible, and the effect of PEI-E on the crystallization behavior of PEEK is weak. The crystallinity of PEEK in the isothermally crystallized PEEK/YS-30 blend specimens decreases with the increase in PI content. But the crystallinity of PEEK in the annealed samples almost keeps unchanged and reaches its maximum value, which is more than 50%. The spherulitic texture of the blends depends on both the blend composition and the molecular structure of the PIs used. The more PI added, the more imperfect the crystalline structure of PEEK. (C) 1998 John Wiley & Sons, Inc.

Thermodynamic properties of ethanol and gasoline blended fuel

The heat capacities (C-p) of five types of gasohol (50 wt % ethanol and 50 wt % unleaded gasoline 93(#) (E50), 60 wt % ethanol and 40 wt % unleaded gasoline 93(#) (E60), 70 wt % ethanol and 30 wt % unleaded gasoline 93(#) (E70), 80 wt % ethanol and 20 wt % unleaded gasoline 93(#) (E80), and 90 wt % ethanol and 10 wt % unleaded gasoline 93(#) (E90), where the "93" denotes the octane number) were measured by adiabatic calorimetry in the temperature range of 78-320 K. A glass transition was observed at 95.61, 96.14, 96.56, 96.84, and 97.08 K for samples from the E50, E60, E70, E80, and E90 systems, respectively. A liquid-solid phase transition and a solid-liquid phase transition were observed in the respective temperature ranges of 118-153 and 155-163 K for E50, 117-150 and 151-164 K for E60, 115-154 and 154-166 K for E70, 113-152 and 152-167 K for E80, and 112-151 and 1581-167 K for E90. The polynomial equations of Cp and the excess heat capacities (C-p(E)), with respect to the thermodynamic temperature, were established through least-squares fitting. Based on the thermodynamic relationship and the equations obtained, the thermodynamic functions and the excess thermodynamic functions of the five gasohol samples were derived.

Mechanistic study on spraying of blended biodiesel using phase Doppler anemometry

Droplet size and dynamics of blended palm oil-based fatty acid methyl ester (FAME) and diesel oil spray were mechanistically investigated using a phase Doppler anemometry. A two-fluid atomizer was applied for dispersing viscous blends of blended biodiesel oil with designated flow rates. It was experimentally found that the atomizer could generate a spray with large droplets with Sauter mean diameters of ca. 30 mm at low air injection pressure. Such large droplets traveled with a low velocity along their trajectory after emerging from the nozzle tip. The viscosity of blended biodiesel could significantly affect the atomizing process, resulting in the controlled droplet size distribution. Blended biodiesel with a certain fraction of palm oil-based FAME would be consistently atomized owing to its low viscosity. However, the viscosity could exert only a small effect on the droplet velocity profile with the air injection pressure higher than 0.2 MPa.

Trends in hospital librarianship and hospital library services: 1989 to 2006.

OBJECTIVE: The research studied the status of hospital librarians and library services to better inform the Medical Library Association's advocacy activities. METHODS: The Vital Pathways Survey Subcommittee of the Task Force on Vital Pathways for Hospital Librarians distributed a web-based survey to hospital librarians and academic health sciences library directors. The survey results were compared to data collected in a 1989 survey of hospital libraries by the American Hospital Association in order to identify any trends in hospital libraries, roles of librarians, and library services. A web-based hospital library report form based on the survey questions was also developed to more quickly identify changes in the status of hospital libraries on an ongoing basis. RESULTS: The greatest change in library services between 1989 and 2005/06 was in the area of access to information, with 40% more of the respondents providing access to commercial online services, 100% more providing access to Internet resources, and 28% more providing training in database searching and use of information resources. Twenty-nine percent (n = 587) of the 2005/06 respondents reported a decrease in staff over the last 5 years. CONCLUSIONS: Survey data support reported trends of consolidation of hospitals and hospital libraries and additions of new services. These services have likely required librarians to acquire new skills. It is hoped that future surveys will be undertaken to continue to study these trends.

The use of evacuation modelling techniques in the design of very large transport aircraft and blended wing body aircraft

Very Large Transport Aircraft (VLTA) pose considerable challenges to designers, operators and certification authorities. Questions concerning seating arrangement, nature and design of recreational space, the number, design and location of internal staircases, the number of cabin crew required and the nature of the cabin crew emergency procedures are just some of the issues that need to be addressed. Other more radical concepts such as blended wing body (BWB) design, involving one or two decks with possibly four or more aisles offer even greater challenges. Can the largest exits currently available cope with passenger flow arising from four or five aisles? Do we need to consider new concepts in exit design? Should the main aisles be made wider to accommodate more passengers? In this paper we demonstrate how computer based evacuation models can be used to investigate these issues through examination of staircase evacuation procedures for VLTA and aisle/exit configuration for BWB cabin layouts.

A framework for e-learning: a blended solution?: current developments in technology-assisted education

This paper describes a Framework for e-Learning and presents the findings of a study investigating whether the use of Blended Learning can fulfill or at least accommodate some of the human requirements presently neglected by current e-Learning systems. This study evaluates the in-house system: Teachmat, and discusses how the use of Blended Learning has become increasingly prevalent as a result of its enhancement and expansion, its relationship to the human and pedagogical issues, and both the positive and negative implications of this reality. [From the Authors]

"Practise what we preach": a social constructivist approach to blended learning

This presentation reports on the formal evaluation, through questionnaires, of a new Level 1 undergraduate course, for 130 student teachers, that uses blended learning. The course design seeks to radicalise the department’s approach to teaching, learning and assessment and use students as change agents. Its structure and content, model social constructivist approaches to learning. Building on the student’s experiences of and, reflections on, previous learning, promotes further learning through the support of “able others” (Vygotsky 1978), facilitating and nurturing a secure community of practice for students new to higher education. The course’s design incorporates individual, paired, small and large group activities and exploits online video, audio and text materials. Course units begin and end with face-to-face tutor-led activities. Online elements, including discussions and formative submissions, are tutor-mediated. Students work together face-to-face and online to read articles, write reflections, develop presentations, research and share experiences and resources. Summative joint assignments and peer assessments emphasise the value of collaboration and teamwork for academic, personal and professional development. Initial informal findings are positive, indicating that students have engaged readily with course content and structure, with few reporting difficulties accessing or using technology. Students have welcomed the opportunity to work together to tackle readings in a new genre, pilot presentation skills and receive and give constructive feedback to peers. Course tutors have indicated that depth and quality of study are evident, with regular online formative submissions enabling tutors to identify and engage directly with student’s needs, provide feedback and develop appropriately designed distance and face-to-face teaching materials. Pastoral tutors have indicated that students have reported non-engagement of peers, leading to the rapid application of academic or personal support. Outcomes of the formal evaluation will inform the development of Level 2 and 3 courses and influence the department’s use of blended learning.

Blended mathematical collaboration using a wiki, GeoGebra and Jing

A wiki, GeoGebra, and a screencasting service were combined to support the online mathematical collaboration of a Grade 10 class. This poster describes the tools employed and the steps taken to develop the skills and attitudes required for this blended learning experience.

A systematic review protocol on the use of online learning and blended learning for teaching clinical skills to undergraduate health professional students

Aim: This paper is a review protocol that will be used to identify, critically appraise and synthesize the best current evidence relating to the use of online learning and blended learning approaches in teaching clinical skills in undergraduate nursing.

Background: Although previous systematic reviews on online learning versus face to face learning have been undertaken (Cavanaugh et al. 2010, Cook et al. 2010), a systematic review on the impact of online learning and blended learning for teaching clinical skills has yet to be considered in undergraduate nursing. By reviewing nursing students’ online learning experiences, systems can potentially be designed to ensure all students’ are supported appropriately to meet their learning needs.

Methods/Design: The key objectives of the review are to evaluate how online-learning teaching strategies assist nursing students learn; to evaluate the students satisfaction with this form of teaching; to explore the variety of online-learning strategies used; to determine what online-learning strategies are more effective and to determine if supplementary face to face instruction enhances learning. A search of the following databases will be made MEDLINE, CINAHL, BREI, ERIC and AUEI. This review will follow the Joanna Briggs Institute guidance for systematic reviews of quantitative and qualitative research.

Conclusion: This review intends to report on a combination of student experience and learning outcomes therefore increasing its utility for educators and curriculum developers involved in healthcare education.