Cairo University

About: Cairo University is a education organization based out in Giza, Egypt. It is known for research contribution in the topics: Population & Medicine. The organization has 33532 authors who have published 55581 publications receiving 792654 citations. The organization is also known as: Fuad I University & King Fuad I University.

Environmental life cycle assessment and techno-economic analysis of triboelectric nanogenerators

Abstract: As the world economy grows and industrialization of the developing countries increases, the demand for energy continues to rise. Triboelectric nanogenerators (TENGs) have been touted as having great potential for low-carbon, non-fossil fuel energy generation. Mechanical energies from, amongst others, body motion, vibration, wind and waves are captured and converted by TENGs to harvest electricity, thereby minimizing global fossil fuel consumption. However, only by ascertaining performance efficiency along with low material and manufacturing costs as well as a favorable environmental profile in comparison with other energy harvesting technologies, can the true potential of TENGs be established. This paper presents a detailed techno-economic lifecycle assessment of two representative examples of TENG modules, one with a high performance efficiency (Module A) and the other with a lower efficiency (Module B) both fabricated using low-cost materials. The results are discussed across a number of sustainability metrics in the context of other energy harvesting technologies, notably photovoltaics. Module A possesses a better environmental profile, lower cost of production, lower CO2 emissions and shorter energy payback period (EPBP) compared to Module B. However, the environmental profile of Module B is slightly degraded due to the higher content of acrylic in its architecture and higher electrical energy consumption during fabrication. The end of life scenario of acrylic is environmentally viable given its recyclability and reuse potential and it does not generate toxic gases that are harmful to humans and the environment during combustion processes due to its stability during exposure to ultraviolet radiation. Despite the adoption of a less optimum laboratory manufacturing route, TENG modules generally have a better environmental profile than commercialized Si based and organic solar cells, but Module B has a slightly higher energy payback period than PV technology based on perovskite-structured methyl ammonium lead iodide. Overall, we recommend that future research into TENGs should focus on improving system performance, material optimization and more importantly improving their lifespan to realize their full potential.

A quantitative model to predict the Egyptian ERP implementation success index

Abstract: Purpose – The purpose of this paper is to develop a quantitative model which helps enterprise resource planning (ERP) implementers in Egypt to predict their implementation success as a function of achieved critical success factors and the organizational culture.Design/methodology/approach – A conceptual framework is formulated and operationalized based on existing literature and a series of interviews with key persons involved in ERP implementation in Egypt. A cross‐sectional survey involving 45 ERP implementers is conducted to collect data used to fit the developed model.Findings – Half the surveyed ERP implementations are considered failures according to the research success metrics. While the critical success factors positively contribute to the success of an ERP implementation, the Egyptian organizational culture hinders its progress. The concept of integration provided by ERP systems is considered relatively new to the Egyptian organizations.Research limitations/implications – The surveyed sample siz...

Effect of core and veneer thicknesses on the color parameters of two all-ceramic systems

Abstract: Statement of problem Specific contributions of the core and the veneer thickness on the appearance of layered disk specimens are not well characterized. Purpose This study examined the effect of varying core and veneer thickness on the color parameters of layered disk specimens made of 2 ceramic systems. Material and methods Disk specimens 16 mm in diameter with core/veneer thickness (mm) of 0.8/0.2 (baseline), 0.8/0.7, 0.8/1.2, 1.0/0.5, 1.3/0.2, and 1.8/0.2 were made from a leucite-reinforced ceramic (IPS Empress; 2B shade), and thickness (mm) of 0.5/0.5 (baseline), 0.5/1.0, 0.5/1.5, 0.8/0.7, 1.0/0.5, and 1.5/0.5 were made from a glass-infiltrated spinell ceramic (In-Ceram Spinell; A2 shade). Color parameters L ∗ , a ∗ , and b ∗ of CIELAB color space were measured against a neutral gray background with a tri-stimulus colorimeter, and ΔE between disk group and its respective baseline group was calculated. Analysis of variance was used to determine the effect of material and core and veneer thickness on the color parameters (α=.05). Results Increasing the total disk thickness resulted in decrease of L ∗ ( P ∗ ( P ∗ ( P P =.0236). For leucite-reinforced ceramic, the core thickness, veneer thickness, and their interaction exhibited significant influence on the mean values of a ∗ and b ∗ ( P ∗ . For spinell ceramic, the core thickness and veneer thickness exhibited significant influence on the mean values of L ∗ and b ∗ ( P ∗ ; the interaction demonstrated significant influence on b ∗ ( P =.0003) but not on L ∗ and a ∗ . Conclusion The color appearance of the layered ceramic disk specimens is strongly influenced not only by the core thickness and veneer thickness, but also by their interaction.