Radio-frequency magnetron sputtering using a Cu target was used to deposit cuprous oxide and cupric oxide thin films on silicon wafer. The substrate bias voltage and the O-2 flow ratio were varied during the deposition. The deposited thin films were characterized using scanning electron microscope. We found that the spherical and pyramid shapes structure of copper oxide thin films were deposited at critical O-2 flow ratio between 7 and 14%. The influence of substrate bias voltage was small and negligible. The deposited thin films were used for sensing characterization using ethanol vapor. Experimental results reveal that the pyramid shape of copper oxide thin film contribute to high respond rate when exposed to ethanol vapor. The respond and recovery rates which were measured at room temperature were very fast. This work had successfully demonstrated the formation of optimized copper oxide thin films and their usage for gas sensing application. (C) 2016 The Authors. Published by Elsevier B.V.

Homeschooling is a parent-led home based education, which is currently enjoying new-discovered acceptance both locally and internationally. To understand this new alternative education, we review a number of homeschooling studies from the local and overseas associated with the history and development of homeschooling, factors that led to homeschooling; outcome or impacts of homeschooling on school, families and children, and concerns, challenges as well as critics of homeschooling. We then document the findings of reasons that led to homeschooling and its outcomes to give an overview of homeschooling to provide a guideline and reflection to parents who intend to homeschool their children. Also, it is significant for the current conventional education system to re-attract families who chose homeschool as well as to refine the current educational practice to cater the modern generation. Meanwhile, we also document concerns, challenges, and critics towards homeschooling to ameliorate homeschooling as the growing alternative.

Cuprous oxide and cupric oxide thin films were deposited on silicon wafer with additional substrate bias voltage using radio-frequency magnetron sputtering of a Cu target with Ar+O-2 discharge plasma. Optical emission spectroscopy was employed to monitor the intensity of atomic Cu and O emission lines at various substrate bias voltages and oxygen flow ratios. Thin film transition from cuprous oxide to cupric oxide phase was observed by X-ray diffraction analysis when the oxygen flow ratio increased. This transition was not influenced by the substrate bias voltage. Optical emission spectroscopy showed a real time monitoring results of the transition from cuprous to cupric oxide thin films The transition was observed at a critical O-2 flow ratio of 7%. The results proposed a tightly control of reactive Cu sputtering through a closed loop and real-time monitoring system for precise copper oxide thin films deposition. (C) 2016 The Authors. Published by Elsevier B.V.