16 research outputs found
Highly transparent and luminescent nanostructured Eu203 doped ZnO films.
Zinc oxide is a wide, direct band gap II-VI oxide semiconductor. Pure and Eu-doped ZnO films are prepared by RF Magnetron sputtering at different doping concentrations (0.5, 1, 3 and 5 wt %). The films are annealed at 500 0C in air for two hours. The structural, morphological and optical properties of the films are characterized using XRD, micro-Raman, AFM, UV-Visible and photoluminescence spectroscopy. The thickness of the films is measured using stylus profilometer. XRD analysis shows that all the films are highly c-axis oriented exhibiting a single peak corresponding to (002) lattice reflection plane of hexagonal wurtzite crystal phase of ZnO. The micro-Raman spectra analysis reveals the presence of E2 high mode in all the samples which is the intrinsic characteristic of hexagonal wurtzite structure of ZnO. The appearance of LO modes indicates the formation of defects such as oxygen vacancies in the films. AFM micrographs show uniform distribution of densely packed grains of size with well defined grain boundaries. All the films exhibit very high transmittance (above 80%) in the visible region with a sharp fundamental absorption edge around 380 nm corresponding to the intrinsic band edge of ZnO. All the films show PL emission in the UV and visible region. Paper presented at the 2nd International Conference on Structural Nano Composites (NANOSTRUC 2014) held 20-21 May 2014 in Madrid, Spain
Prevalence and risk factors of postpartum depression, general depressive symptoms, anxiety and stress (PODSAS) among mothers during their 4-week postnatal follow-up in five public health clinics in Perak: a study protocol for a cross-sectional study
Introduction Postpartum depression, general depressive symptoms, anxiety and stress (PODSAS) are often overlooked, and may cause morbidity to new mothers, their babies and families. This study aims to determine the point prevalence of depression (post partum and general), anxiety and stress among mothers in five public health clinics in Perak at 4āweeks postdelivery and identify their associated risk factors. Findings from this study will be used to identify the needs for early screening and detection, encourage development of interventions to reduce its occurrence and support mothers with PODSAS. Methods and analysis This cross-sectional study will recruit 459 postpartum mothers during their 4-week postnatal follow-up in five selected public health clinics in Perak from September 2019 to May 2020. Participants will be mothers aged 18 years and above at 4 weeks postdelivery who are able to understand the English and Malay languages. Non-Malaysians and mothers with known diagnosis of psychotic disorders will be excluded from the study. Sociodemographic information and possible risk factors of the participants will be captured via a set of validated questionnaires, postpartum depression (PPD) will be measured using the Edinburgh Postpartum Depression Scale questionnaire and general depressive symptoms, anxiety and stress will be measured using the 21-item Depression, Anxiety and Stress Scale. Data analysis will be conducted using SPSS V.25.0 (IBM). Besides descriptive statistics, multivariable regression analyses will be done to identify possible risk factors and their independent associations with depression (PPD and general depressive symptoms, combined and separately), anxiety and stress