62 resultados para UV-written


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Electrospun polyelectrolyte hydrogel nanofibres are being developed for many applications including artificial muscles, scaffolds for tissue engineering, wound dressings and controlled drug release. For electrospun polyelectrolytes, a post-spinning crosslinking process is necessary for producing a hydrogel. Typically, radiation or thermal crosslinking routines are employed that require multifunctional crosslinking molecules and crosslink reaction initiators (free radical producers). Here, ultraviolet subtype-C (UVC) radiation was employed to crosslink neat poly(acrylic acid) (PAA) nanofibres and films to different crosslink densities. Specific crosslink initiators or crosslinking molecules are not necessary in this fast and simple process providing an advantage for biological applications. Scanning probe microscopy was used for the first time to measure the dry and wet dimensions of hydrogel nanofibres. The diameters of the swollen fibres decrease monotonically with increasing UVC radiation time. The fibres could be reversibly swollen/contracted by treatment with solutions of varying pH, demonstrating their potential as artificial muscles. The surprising success of UVC radiation exposure to achieve chemical crosslinks without a specific initiator molecule exploits the ultrathin dimensions of the PAA samples and will not work with relatively thick samples.

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Currently viscose production methods are primarily used to process bamboo into commercial textile fibres. However, viscose methods use large quantities of chemicals and hence the process is not considered as environmentally friendly. The process also fails to retain bamboo’s inherent unique properties such as ultraviolet (UV) screening and antibacterial functions. Hence, it is necessary to design an effective and more eco-friendly manufacturing method that would also retain the unique properties of raw bamboo plant into the fibres. In this research, bamboo was processed using new methods involving thermo mechanical treatments such as ultra-sonication, shaker milling and boiling with continuous stirring. Sodium hydroxide, hydrogen peroxide, enzyme and water were used separately in this process and their effects on fibre processing were compared. The morphology and UV shielding ability were analysed before and after processing. It was demonstrated that bamboo can be processed into fibres using only water and ball milling without the aid of any hazardous chemicals. The combination of mild acid hydrolysis and ultrasonic treatment with hydrogen peroxide was effective in the fibre separation and provided better appearance of fibres.

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Allan Luke (2008) uses a “pedagogical economy where literacy education is taken as a cultural gift”. This paper reports on the digital oral feedback provided to pre-service teachers in a literacy unit and explores the pedagogical gift this feedback is to the teacher educators marking this work. Rather than mark their written work as individual lecturers, we collaboratively read the assignment and recorded the sound file of the conversation around each assignment. We then participated in another conversation with a critical friend, which enabled us to explore the impact of this form of assessment on our professional identities as teacher educators. We found these conversations provided a rich context for our professional learning about ourselves as teacher educators, as well as specific content knowledge we both brought to the teaching of this unit. We found we were working as a team to provide more in-depth feedback of the assessment criteria for each assignment than we did with written feedback. Through this dialogical feedback we were able to construct the pre-service teachers' assignments as an important textual gift in our collaborative professional learning about assessment, and in exploring our beliefs and practices as teacher educators.

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The detrimental effects of UV radiation are having a significant impact on our life and environment. The development of effective UV shielding agents is therefore of great importance to our society. ZnO nanoparticles are considered to be one of the most effective UV blocking agents. However, the development of ZnO-based UV shielding products is currently hindered due to the adverse effects of the inherent photocatalytic activity exhibited by ZnO. This paper reports our recent study on the possibility of reducing the photoactivity of ZnO nanoparticles via surface modification and impurity doping. It was found that the photoactivity was drastically reduced by SiO2-coatings that were applied to ZnO quantum dots using the Stöber method and a microemulsion technique. The effect of transition metal doping on the photoactivity was also studied using mechanochemical processing and a co-precipitation method. Cobalt doping reduced the photoactivity, while manganese doping led to mixed results, possibly due to the difference in the location of dopant ions derived from the difference in the synthesis methods.

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The effect of nanometer anatase TiO2 was investigated on the photocatalytic degradation of phenanthrene on soil surfaces under a variety of conditions. After being spiked with phenanthrene, soil samples loaded with different amounts of TiO2 (0 wt.%, 1 wt.%, 2 wt.%, 3 wt.%, and 4 wt.%) were exposed to UV-light irradiation for 25 hr. The results indicated that the photocatalytic degradation of phenanthrene followed the pseudo first-order kinetics. TiO2 significantly accelerated the degradation of phenanthrene with the half-life reduced from 45.90 to 31.36 hr for TiO2 loading of 0 wt.% and 4 wt.%, respectively. In addition, the effects of H2O2, light intensity and humic acid on the degradation of phenanthrene were investigated. The degradation of phenanthrene increased with the concentration of H2O2, light intensity and the concentration of humic acids. It has been demonstrated that the photocatalytic method in the presence of nanometer anatase TiO2 was a very promising technology for the treatments of soil polluted with organic substances in the future.

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An Excel spreadsheet which includes every peer reviewed publication written by occupational therapists in mental health since 2000. It is updated each January to include the previous years publications. Information recorded includes author number, author designation, bibliographic details (i.e. title, journal), categorisation according to doing/being/becoming/belonging, levels of evidence and days between submission and acceptance, and acceptance and publication.

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This article reports on a self-study of teacher educators involved in a preservice teacher unit on literacy. In this study the teacher educators provided the preservice teachers with digital oral feedback about their final unit of work. Rather than marking written work as individual lecturers, we collaboratively read each assignment and recorded a sound file of our conversation. We constructed our collaborative marking of each assignment as a “cultural gift” to our own professional learning. We found that we were providing more in-depth feedback on the assessment criteria for each assignment than we would have with written feedback prepared individually. We also uncovered tensions in relation to our preferred modalities associated with the digital marking.

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At the outset, it should be noted that under the watch of the 2005 Gambling Act, there is robust evidence of increasing harms caused by gambling. The increase in problem gambling from 0.6% (prior to the implementation of the Act) to 0.9% of the British population reported in the British Gambling Prevalence Survey (BGPS) (2010) is significant at the .05 level; which is internationally recognised as a robust significance level. This represents a 50% rise in problem gambling since the Act was implemented. It was disingenuous of the Gambling Commission to report the results as “not statistically relevant” and “at the margins of statistical relevance” in its media release concerning the study. This equates to around 451,000 adults aged 16 and over experiencing serious gambling-related problems and significant additional numbers experiencing moderate problems. Regular (approximately monthly) use of gaming machines, fixed odds betting terminals (FOBTs) in betting shops, casino games and online gambling are associated with problem gambling.

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Self-efficacy is a belief. It can encourage or hamper students from learning to their full potential. Students who are efficacious are more motivated, more persistent to meet their goals and are more likely to take learning risks. The research into the self-efficacy of students classified as verbally or non-verbally gifted is in its infancy. This book details a Doctoral dissertation that investigated the written English self-efficacy of adolescent students. Results identified verbally gifted students had higher written English self-efficacy, were more intrinsically motivated, had higher levels of creativity and wrote superior essays compared to non-verbally gifted and non-gifted students. Findings highlighted differences between gender as female student?s recorded higher self-efficacy and written English performance scores and interestingly, students from lower socio-economic backgrounds reported higher self-efficacy compared to students from higher socio-economic backgrounds. Pedagogical implications are considered with teachers encouraged to realise the impact of self-efficacy upon student learning, motivation and persistence regardless of their academic ability.