No abstract

No abstract

Porcelain insulators prepared from locally available ceramic materials, such as Hosaena clay, quartz, partially replaced feldspar by cullet (rich in alkaline materials). The physical and electrical properties, such as water absorption, apparent porosity, bulk density, linear shrinkage, and dielectric strength as a function of firing temperature, were evaluated. The XRD and AAS measurement results show Hosaenna clay mainly belongs to kaolinite minerals with a sufficient SiO2 (45.60wt. %), Al2O3 (35.52wt. %), and it possesses reasonable plasticity nature. The SEM and Electrical properties measurement shows the porcelain insulators fired at 1150 C & 1200 C showed homogenized primary and secondary mullite with optimum glassy phase and good dielectric strength for practical applications. The primary & secondary mullite and glassy phases were grown early at a firing temperature of 1150 and 1200 C, due to the partial replacement of feldspar by cullet. The porcelain insulator prepared from the composition of 45%clay, 35%feldspar, 10%quartz and 10%cullet and fired at 1200 C showed dielectric strength 8.9kv/mm, water absorption (0.459%), apparent porosity (1.530%), bulk density (4.29 g/cm 3 ), and linear shrinkage (4.18%). Therefore, incorporating economic alkaline materials such as cullet to improve the alkalinity of the locally available clay materials, Hosaenna clay, Arero feldspar, and Arero quartz reduces the firing temperature with excellent dielectric strength.

No abstract

Rainwater harvesting (RWH) has been practiced in Ethiopia since ancient times, but it has shown little development, because of inefficient techniques. Most efforts to capture rainwater did not show significant results owing to poor design and implementation resulted from slow technical development. This paper details design improvements tested on a demonstration site as well as an analysis of operational parameters. Similar, rainwater quality improvement techniques applied for the system are also discussed. Various scenarios were studied relating design and operating parameters for replicability and decision-making before construction stage. Common components of existing RWH systems in Ethiopia are discussed and contrasted with the implemented demonstration RWH system. Moreover, particle separation theory and techniques are introduced as quality improvement techniques. Results of the analysis also suggest a possibility of satisfying building demand by utilizing the installed system and it also shows the potential of RWH in Ethiopia as an alternative water source.