Influence of OH −

The influence of varying OH− ion concentration on the surface morphology of chemically deposited ZnO-SiO2 nanostructures on glass substrate was investigated. The morphological features, phase structure, and infrared characteristics were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR), respectively. Results revealed that silica significantly changes the hexagonal morphology of bare ZnO rod to “pointed tips” when using low initial OH− precursor concentration. Increasing OH− ion concentration resulted in a “flower-like” formation of ZnO-SiO2 and a remarkable change from “pointed tips” to “hemispherical tips” at the top surface of the rods. The surface capping of SiO2 to ZnO leads to the formation of these “hemispherical tips.” The infrared spectroscopic analysis showed the characteristics peaks of ZnO and SiO2 as well as the Si-O-Zn band which confirms the formation of ZnO-SiO2. Phase analysis manifested that the formed ZnO-SiO2 is of wurtzite structure. Furthermore, a possible growth mechanism is proposed based on the obtained results

A study on the mechanical properties of underground, open-heap burned rice hull ash as a partial cement substitute

This paper presents the findings of a study done on the properties of open-heap burned, burned, unground Rice Hull Ash as a partial cement substitute and pozzolanic materials. The study specifically measured the effect on the compressive and tensile strength of concrete by varying the RHA content of the pre-determined mix design. The study also observed the acid resistance of the mix that brought about the optimum performance. Presented herewith are the results of the experiments done in connection of this study, as well as analysis of the said data, and all pertinent data connected to the production of RHA concrete

Problems and coping patterns of widows

Widowhood is the state of losing a husband and remaining unmarried (Geddes, 1979). This study involved the similarities and differences of problems encountered and coping strategies in different stages of adulthood. The chain referral method of sampling, was used to obtain 15 respondents, from the three different levels of adulthood. The in-depth interview was used in gathering the data needed. Findings show that more young and middle aged widows experienced more family problems than late adult widows. All the widows experienced health problems, as a result of the loneliness they experienced. The most common coping strategies, the widows employed is the preventive type of coping. With this the researchers found that the marital relationship of the widow has no effect on the problems encountered and coping strategies employed. While the relationship with children and the support systems of the widows only had a minimal effect