Biomimetic materials and technologies for carbon neutral cities in South Africa: a literature review
- Authors: Oguntona, Olusegun Aanuoluwapo , Aigbavboa, Clinton Ohis
- Date: 2017
- Subjects: Biomimicry , Construction industry , CO2 emission
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/259187 , uj:27265 , Citation: Oguntona, O.A. & Aigbavboa, C.O. 2017. Biomimetic materials and technologies for carbon neutral cities in South Africa: a literature review. Creative Construction Conference 2017, CCC 2017, 19-22 June 2017, Primosten, Croatia. doi: 10.1016/j.proeng.2017.07.185
- Description: Abstract: The accelerating decline in the environment and increasing atmospheric concentration of greenhouse gases (GHGs) are closely linked to human activities. This has caused the menace of climate change with the impact globally felt. The continent of Africa, given its geographical location, is believed to be more vulnerable and will severely feel these impacts. To curtail this, mitigation and adaptation have been recognised as the most potent strategies to curtail the challenge of climate change. Increased adaptive capabilities of infrastructures and systems in South Africa is, therefore, imperative. This paper explores biomimicry, a new field that studies and emulates the forms, processes, and strategies found in natural organisms to solve human challenges. For its over 3.8 billion years of evolution, nature has effectively and efficiently tackled many of the challenges mankind is grappling wi th today. Hence, the objective of this study is to evaluate and present existing biomimetic materials and technologies which contribute less to the degradation of the environment. Biomimetic materials and technologies, known to possess sustainable credentials will reduce the release of GHGs and has the potential for carbon sequestration. The result will help offer sustainable alternatives to those materials and products which significantly contribute to the increase in carbon footprint.
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Efficient low-cost materials for solar energy applications : roles of nanotechnology
- Authors: Ebhota, Williams S. , Tien-Chien, Jen
- Date: 2018
- Subjects: Photovoltaic cell low-cost materials , Photovoltaic solar technologies , CO2 emission
- Language: English
- Type: Book Chapter
- Identifier: http://hdl.handle.net/10210/290318 , uj:31515 , Citation: Ebhota, W.S. & Tien-Chien, J. 2018. Efficient low-cost materials for solar energy applications : roles of nanotechnology.
- Description: Abstract: The generation of energy to meet the increasing global demand should not compromise the environment and the future. Therefore, renewable energies have been identified as potential alternatives to fossil fuels that are associated with CO2 emissions. Subsequently, photovoltaic (PV) solar system is seen as the most versatile and the largest source of electricity for the future globally. Nanotechnology is a facilitating tool that offers a wide range of resources to resolve material challenges in different application areas. This studies X-rays, energy trilemma, potential nanotechnology-based materials for low-cost PV solar cell fabrication, and atomic layer deposition (ALD). In pursuance of improved performance, PV solar-cell technologies have revolutionized from first-generation PV solar cells to third-generation PV solar cells. The efficiency (19%) of second-generation PV cells is higher than the efficiency (15%) of first-generation cells. The second-generation PV cell technologies include a-Si, CdTe and Cu(In,Ga)Se2), Cu(In,Ga)Se2 (CIGS) cells. The third-generation PV cells are organic-inorganic hybrid assemblies, nanostructured semiconductors, and molecular assemblies. This nanocomposite- based technology aims at developing low-cost high efficiency PV solar cells. The nanotechnology manufacturing technique, ALD, is seen as the future technology of PV solar cell production.
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Blended tropical almond residue for fuel production: characteristics, energy benefits, and emission reduction potential
- Authors: Olatunji, Obafemi O. , Akinlabi, Stephen , Madushele, Nkosinathi , Adedeji, Paul A. , Ndolomingo, Matumuene J. , Thivhani, Meshack
- Date: 2020
- Subjects: Blended tropical almond , Clean fuel production , CO2 emission
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/436512 , uj:37867 , Olatuni, O.O. et al. 2020: Blended tropical almond residue for fuel production: characteristics, energy benefits, and emission reduction potential. DOI: https://doi.org/10.1016/j.jclepro.2020.122013
- Description: Abstract: , Besides the nuts produced from almond cultivation, it also generates several million tonnes of residue that include hulls, shells, leaves, pruning, and inedible kernels which are valuable feedstocks in clean fuel production. In this article, blended tropical almond residue of two particle sizes (NT15 and NT25) were investigated. The heating, proximate and ultimate values were reported while the chemical composition of the ash was determined. Also, the pore structure and the inherent functional groups were determined for the particle sizes. The thermogravimetric analysis was also carried out to determine the thermal behaviour at different heating rate (10, 15, 30 oCmin-1) in inert environment while the kinetic parameters were evaluated based on three non-isothermal methods (Flynn– Wall–Ozawa, Kissinger–Akahira–Sunose and distributed activation energy model). Notably, the ash content was higher in the finer particle size NT15 (1.11 %) compared to NT25 (0.87 %). Low pore surface area (1.218-0.970 m²g-1) agrees with literature values while a slight difference in pore size distribution was observed during adsorption at higher relative pressure. A representation of mixed functional groups whose wavelength falls within 527 cm-1, 848 cm-1, 991 cm-1, 1035 cm-1, 1179 cm-1, 1597 cm-1, 1772 cm-1, 2849 cm-1 was observed with no significant difference between the two particle sizes. The average activation energy, Ea for NT15 and NT25 were in the range of 127.4-131 kJmol-1 and 129-133 kJmol-1 respectively for all the three methods, with the lowest Ea (127.4 kJmol-1) and compensation factor, K0 (1.29E+12 min-1) obtained for the smaller particle size (NT15) based on Kissinger–Akahira–Sunose method. Finally, the energy benefits and CO2 emission reduction potential were estimated. The highest energy potential is in USA (4.17 Mtoe) while Morocco has the highest emission reduction at 3.28 %. The information obtained from this study can be used in the scaling up of bioreactors which can further support the global clean energy drive and reduce environmental pollution.
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