Transition from n- to p-type of spray pyrolysis deposited Cu doped ZnO thin films for NO2 sensing

The structural, optical, and gas-sensing properties of spray pyrolysis deposited Cu doped ZnO thin films were investigated. Gas response of the undoped and doped films to N02 (oxidizing) gas shows an increase and decrease in resistance, respectively, indicating p-type conduction in doped samples. The UV-Vis spectra of the films show decrease in the bandgap with increasing Cu concentration in ZnO. The observed p-type conductivity is attributed to the holes generated by incorporated Cu atoms on Zn sites in ZnO thin films. The X-ray diffraction spectra showed that samples are polycrystalline with the hexagonal wurtzite structure and increasing the concentration of Cu caused a decrease in the intensity of the dominant (002) peak. The surface morphology of films was studied by scanning electron microscopy and the presence of Cu was also confirmed by X-ray photoelectron spectroscopy. Seebeck effect measurements were utilized to confirm the p-type conduction of Cu doped ZnO thin films. Copyright © 2009 American Scientific Publishers All rights reserved.

Ambient temperature and morbidity: A review of epidemiological evidence

OBJECTIVE: This paper reviews the epidemiological evidence on the relationship between ambient temperature and morbidity. It assesses the methodological issues in previous studies, and proposes future research directions. DATA SOURCES AND DATA EXTRACTION: We searched the PubMed database for epidemiological studies on ambient temperature and morbidity of non-communicable diseases published in refereed English journals prior to June 2010. 40 relevant studies were identified. Of these, 24 examined the relationship between ambient temperature and morbidity, 15 investigated the short-term effects of heatwave on morbidity, and 1 assessed both temperature and heatwave effects. DATA SYNTHESIS: Descriptive and time-series studies were the two main research designs used to investigate the temperature–morbidity relationship. Measurements of temperature exposure and health outcomes used in these studies differed widely. The majority of studies reported a significant relationship between ambient temperature and total or cause-specific morbidities. However, there were some inconsistencies in the direction and magnitude of non-linear lag effects. The lag effect of hot temperature on morbidity was shorter (several days) compared to that of cold temperature (up to a few weeks). The temperature–morbidity relationship may be confounded and/or modified by socio-demographic factors and air pollution. CONCLUSIONS: There is a significant short-term effect of ambient temperature on total and cause-specific morbidities. However, further research is needed to determine an appropriate temperature measure, consider a diverse range of morbidities, and to use consistent methodology to make different studies more comparable.

A transition program in first year law : adopting the First Year Curriculum Principles

The First Year Curriculum Principles espouse a student-focused consistent and explicit curriculum, acknowledging diversity and the need to scaffold skills and learning. Commencing law students are no different to other first year students in that they must deal with changes in teaching and learning approaches and expectations. As well as the generic issues of transition, law students must grapple with learning the skills which are necessary for the study of law from the very start of their degree. A transition program at the commencement of a law degree as part of a planned first year curriculum provides an opportunity to introduce students to the study of law, the requisite skills as well as assist with transition to tertiary education.

The transition to school of children with developmental disabilities : views of parents and teachers

The transition from early intervention programs to inclusive school settings presents children with developmental disabilities with a range of social challenges. In Queensland, in the year of transition to school, many children with developmental disabilities attend an Early Childhood Development Program for 2 to 3 days each week and also begin attendance in a mainstream program with the latter increasing to full-time attendance during the year. Quantitative and qualitative data were collected by parent interviews and teacher questionnaires for 62 children participating in the Transition to School Project regarding their perceptions of the success of the transition process and the benefits and challenges of inclusion. Both parents and teachers saw a range of benefits to children from their inclusion in ‘regular’ classrooms, with parents noting the helpfulness of teachers and their support for inclusion. Challenges noted by parents included the school’s lack of preparation for their child’s particular developmental needs especially in terms of the physical environment while teachers reported challenges meeting the needs of these children within the context and resources of the classroom. Parents were more likely than teachers to view the transition as easy. Correlational analyses indicated that teachers were more likely to view the transition as easy when they felt that the child was appropriately placed in a ‘regular’ classroom. Findings from this project can inform the development of effective transition-to-school programs in the early school years for children with developmental disabilities.

Bispectral and trispectral characterization of transition to chaos in the Duffing oscillator

Higher-order spectral (bispectral and trispectral) analyses of numerical solutions of the Duffing equation with a cubic stiffness are used to isolate the coupling between the triads and quartets, respectively, of nonlinearly interacting Fourier components of the system. The Duffing oscillator follows a period-doubling intermittency catastrophic route to chaos. For period-doubled limit cycles, higher-order spectra indicate that both quadratic and cubic nonlinear interactions are important to the dynamics. However, when the Duffing oscillator becomes chaotic, global behavior of the cubic nonlinearity becomes dominant and quadratic nonlinear interactions are weak, while cubic interactions remain strong. As the nonlinearity of the system is increased, the number of excited Fourier components increases, eventually leading to broad-band power spectra for chaos. The corresponding higher-order spectra indicate that although some individual nonlinear interactions weaken as nonlinearity increases, the number of nonlinearly interacting Fourier modes increases. Trispectra indicate that the cubic interactions gradually evolve from encompassing a few quartets of Fourier components for period-1 motion to encompassing many quartets for chaos. For chaos, all the components within the energetic part of the power spectrum are cubically (but not quadratically) coupled to each other.