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Effect of Sand on the Properties of Compressed Soil-Cement Stabilized Blocks
Lawrence Muhwezi,
Stella Eve Achanit
Issue:
Volume 4, Issue 1, June 2019
Pages:
1-6
Received:
26 September 2018
Accepted:
1 March 2019
Published:
26 March 2019
Abstract: With the growing concern of awareness regarding sustainable building materials and environmental issues, a number of people have resorted to using soil-cement stabilized blocks (SCSBs) as an alternative for burnt bricks. However, these stabilized blocks are also known for their high-water absorption capacity during wet seasons which affects their strength and durability. The study conducted involved a series of physical properties tests of soil (particlesize distribution analysis and Plasticity Index test); mechanical property tests (compressive strength test and water absorption test), which were undertaken in accordance with the ASTM standard. It compared the compressive strengths and water absorption capacity amongSCSBs with a sand blend at different proportions of mixture (10%, 20% and 30%) and those without sand, maintaining thequantity of cement constant at 5%. The results indicated that the compressed stabilized earth blocks using silty clay soil blended with sand and with 5% cement were stronger compared to those without sand. However, the water absorption capacity of the blocks (both with and without sand), revealed no significant difference except for the blocks with 20% of sand which proved to have the lowest water absorption capacity (15%). The SCSBs of 10% addition of sand proved to be the strongest with compressive strength of 2 Mpa. The study concluded that 10% blend of sand could be adopted in block manufacturing for sustainable low-cost housing construction. Having known the strength of these blocks, the users can go ahead and use them in low cost housing construction projects.
Abstract: With the growing concern of awareness regarding sustainable building materials and environmental issues, a number of people have resorted to using soil-cement stabilized blocks (SCSBs) as an alternative for burnt bricks. However, these stabilized blocks are also known for their high-water absorption capacity during wet seasons which affects their s...
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Correlation Between the Preparation Methods and the Structural Morphologies of Organometallic Halide Perovskite Thin Films
Mwende Mbilo,
Agumba Onyango John,
Fanuel Keheze Mugwang’a
Issue:
Volume 4, Issue 1, June 2019
Pages:
7-12
Received:
15 March 2019
Accepted:
22 April 2019
Published:
11 May 2019
Abstract: Organometallic halide perovskites are emerging as a promising class of materials for optoelectronic and electrical applications. The degree of molecular ordering that depends on nucleation and growth processes can tune their morphological structure which in turn affects the resultant optical, electronic and electrical properties. Studies have been carried out in this area of research, to some degree, but not conclusive. A systematic study on how the preparation method determines the various morphologies of the resultant perovskite thin films is thus necessary. This work presents a study that was carried out to assess the relationship between different deposition methods and the resulting morphologies of organometallic halide perovskite thin films. In this study, single step solution deposition method, two step solution deposition method and two step drop casting solution deposition methods were used to prepare the perovskite thin films. Concentration, annealing temperature, blade coating speed and dipping times were varied during perovskite deposition processes and the optical micrographs of the prepared films obtained using Zeiss Axio 100 optical microscope fitted with AxioCam 105 color camera. Significant difference in morphologies of the structures prepared using different deposition methods was observed. This observable difference in morphologies may be related to the molecular order of the film structures.
Abstract: Organometallic halide perovskites are emerging as a promising class of materials for optoelectronic and electrical applications. The degree of molecular ordering that depends on nucleation and growth processes can tune their morphological structure which in turn affects the resultant optical, electronic and electrical properties. Studies have been ...
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Concentration of Heavy Metals in Some Animal Meats from Merowe–City–Sudan
Mawia Hassan Elsaim,
Aisha Abdelrhaman
Issue:
Volume 4, Issue 1, June 2019
Pages:
13-16
Received:
26 March 2019
Accepted:
29 April 2019
Published:
27 May 2019
Abstract: This study was to determine the concentrations of essential metals such as namely Copper, Cobalt, Manganese, Iron and Zinc) and heavy metals such as Cadmium and Lead performed by atomic absorption spectrophotometer (AAS) in two sample of some animal meats of Mutton (sheep) and Beef (cow), collected from the district popularly in Merowe-city, north Sudan. The essential metals estimation in the investigated samples indicated the following range of concentration (0.19 -0.28mg/kg) for Cobalt, (0.36-0.31mg/kg) for Copper, (3.16-5.44mg/kg) for Iron, (0.12-0.15mg/kg) for Manganese, and (5.30 -7.6mg/kg) for Zinc respectively. These concentrations of essential metals are in the range of human necessities. The concentration of toxic metals (Cadmium and lead) in two samples is not mean detected. The results also showed that were significant differences of some essential elements concentrations (Mg/kg) in two samples. Generally meat of Beef was found to have to highest significant levels of metals and the meat of Mutton lowest levels. The concentration of Iron and Zinc concentration in all samples were within the tolerance limits.
Abstract: This study was to determine the concentrations of essential metals such as namely Copper, Cobalt, Manganese, Iron and Zinc) and heavy metals such as Cadmium and Lead performed by atomic absorption spectrophotometer (AAS) in two sample of some animal meats of Mutton (sheep) and Beef (cow), collected from the district popularly in Merowe-city, north ...
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