| 1171. |
- Elberry, Ahmed M., et al.
(author)
-
Large-scale compressed hydrogen storage as part of renewable electricity storage systems
- 2021
-
In: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 46:29, s. 15671-15690
-
Research review (peer-reviewed)abstract
- Storing energy in the form of hydrogen is a promising green alternative. Thus, there is a high interest to analyze the status quo of the different storage options. This paper focuses on the large-scale compressed hydrogen storage options with respect to three categories: storage vessels, geological storage, and other underground storage alternatives. In this study, we investigated a wide variety of compressed hydrogen storage technologies, discussing in fair detail their theory of operation, potential, and challenges. The analysis confirms that a techno-economic chain analysis is required to evaluate the viability of one storage option over another for a case by case. Some of the discussed technologies are immature; however, this does not rule out these technologies; rather, it portrays the research opportunities in the field and the foreseen potential of these technologies. Furthermore, we see that hydrogen would have a significant role in balancing intermittent renewable electricity production. (c) 2021 The Author(s). Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).
|
|
| 1172. |
- Elberry, Ahmed M., et al.
(author)
-
Seasonal hydrogen storage for sustainable renewable energy integration in the electricity sector : A case study of Finland
- 2021
-
In: Journal of Energy Storage. - : Elsevier BV. - 2352-152X .- 2352-1538. ; 44
-
Journal article (peer-reviewed)abstract
- Wind power is rapidly growing in the Finnish grid, and Finland's electricity consumption is low in the summer compared to the winter. Hence, there is a need for storage that can absorb a large amount of energy during summer and discharge it during winter. This study examines one such storage technology, geological hydrogen storage, which has the potential to store energy on a GWh scale and also over longer periods of time. Finland's electricity generation system was modelled with and without hydrogen storage using the LEAP-NEMO modeling toolkit. The results showed about 69% decline in carbon dioxide emissions as well as a decline in the fossil fuel-based power accompanied with a higher capability to meet demand with less imports in both scenarios. Finally, a critical analysis of the Finnish electricity mix with and without hydrogen storage is presented.
|
|
| 1173. |
- Eldeeb, Tarek M., et al.
(author)
-
Novel three-dimensional chitosan-carbon nanotube–PVA nanocomposite hydrogel for removal of Cr6+ from wastewater
- 2020
-
In: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994. ; 184, s. 163-177
-
Journal article (peer-reviewed)abstract
- A novel hybrid nanocomposite adsorbent was prepared by encapsulation of multi-walled carbon nano-tubes within polyvinyl alcohol/chitosan hydrogel (Cs/MWCNT/PVA) and cross-linked with glu-taraldehyde. The chemical reactions between the components affected the position and intensities of the infrared bands. This nanocomposite has excellent Cr6+ ions adsorption efficiency. The optimal conditions of the process as a function of the solution pH, contact time, ionic strength, and sorbent weight were investigated. The batch equilibrium experiments revealed that the most suitable pH for chromium adsorption was at 1.5. The maximum adsorption capacity for the hydrogel was 217.4 mg g–1 as estimated by the Langmuir model. Other isotherm models, such as Freundlich and Temkin, were used to analyze the experimental data and the models’ parameters were evaluated. The pseudo-first and second-order, Elovich, intraparticle diffusion, and film diffusion kinetic models were also inves-tigated. The obtained results enabled to estimate the possibility to use the Cs/MWCNT/PVA hydrogel in the removal of Cr6+ ions from wastewater by adsorption.
|
|
| 1174. |
- Eldesoky, Ahmed H.M., et al.
(author)
-
The suitability of the urban local climate zone classification scheme for surface temperature studies in distinct macroclimate regions
- 2021
-
In: Urban Climate. - : Elsevier BV. - 2212-0955. ; 37
-
Journal article (peer-reviewed)abstract
- The Local Climate Zone (LCZ) classification scheme, initially designed to distinguish between standard built (urban) and non-built (land cover) types in terms of screen-level air temperature relevant for urban heat island (UHI) studies, has been widely used for land surface temperature (LST) and surface urban heat island (SUHI) studies. However, some concerns remain about the global suitability of the scheme for LST and SUHI studies in different macroclimate regions. By analyzing and comparing a large number of representative LCZ sites and multi-year remotely-sensed LST data, the aim of this work is twofold. Firstly, to study the suitability of the LCZ scheme, with a focus on the built types, for surface temperature studies in four distinct macroclimate regions, namely, the tropical, the arid, the temperate and the cold. Secondly, to understand the influence of the macroclimate region on the LST and SUHI characteristics of the standard LCZ built types. Results show that the urban LCZ standard scheme is applicable, with varying degrees, to all macroclimate regions other than the arid, where a LCZ subclassification might be essential. Also, it has been demonstrated that most LCZ built types exhibit significantly different LST and SUHI characteristics across the remaining macroclimate regions.
|
|
| 1175. |
- Elewa, Ahmed M., et al.
(author)
-
Comparison between erector spinae plane block and paravertebral block regarding postoperative analgesic consumption following breast surgery : a randomized controlled study
- 2022
-
In: BMC Anesthesiology. - : BMC. - 1471-2253 .- 1471-2253. ; 22:1
-
Journal article (peer-reviewed)abstract
- Background: Pain control following breast surgery is of utmost importance in order to reduce the chance of chronic pain development, and facilitate early rehabilitation. The erector spinae plane block (ESPB) is a recently developed regional anaesthesia procedure successfully used for different types of surgical procedures including thoracic and abdominal surgeries. Methods: A double-blind, randomized, controlled trial was conducted on 90 patients who were scheduled for modified radical mastectomy (MRM). Patients were randomly categorized into groups I (women who underwent ESPB), II (women who underwent paravertebral block (PVB), and III (women who underwent general anaesthesia). Results: The ESPB (4.9 +/- 1.2 mg) and PVB (5.8 +/- 1.3 mg) groups had significantly lower total morphine consumption than the control group had (16.4 +/- 3.1 mg; p < 0.001). Notably, patients in the ESPB group had insignificantly lower morphine consumption than those in the PVB group had (p= 0.076). Moreover, patients in the ESPB and PVB groups had a significantly longer time to first required anaesthesia than those in the control group (7.9 +/- 1.2 versus 7.5 +/- 0.9 versus 2 +/- 1.2 h, respectively; p<0.001).The postoperative visual analog scale scores were lower in the ESPB and PVB groups than in the control group on the first 24 h after the procedure (p< 0.001). Conclusion: ESPB and PVB provide effective postoperative analgesia for women undergoing MRM. The ESPB appears to be as effective as the PVB.
|
|
| 1176. |
- Elewa, Ahmed M., et al.
(author)
-
Erector spinae plane block versus paravertebral block in analgesic outcomes following breast surgery
- 2023
-
In: BMC Anesthesiology. - : BMC. - 1471-2253. ; 23:1
-
Journal article (other academic/artistic)abstract
- This article represents the response to the inquiries adopted by Dr. Raghuraman M Sethuraman, M.D., regarding our recently published study which compared the erector spinae plane block (ESPB) versus paravertebral block (PVB) regarding postoperative analgesic consumption following breast surgeries (Elewa et al, BMC Anesthesiol 22: 1-9, 2022). We would like to introduce our appreciation and gratitude to the author for his interest in our work, despite being inaccurate in some of his comments.
|
|
| 1177. |
- Elmisery, Ahmed M., et al.
(author)
-
Privacy-enhanced middleware for location-based sub-community discovery in implicit social groups
- 2016
-
In: Journal of Supercomputing. - : Springer Science+Business Media B.V.. - 0920-8542 .- 1573-0484. ; 72:1, s. 247-274
-
Journal article (peer-reviewed)abstract
- In our connected world, recommender services have become widely known for their ability to provide expert and personalize information to participants of diverse applications. The excessive growth of social networks, a new kind of services are being embraced which are termed as "group based recommendation services", where recommender services can be utilized to discover sub-communities within implicit social groups and provide referrals to new participants in order to join various sub-communities of other participants who share similar preferences or interests. Nevertheless, protecting participants' privacy in recommendation services is a quite crucial aspect which might prevent participants from exchanging their own data with these services, which in turn detain the accuracy of the generated referrals. So in order to gain accurate referrals, recommendation services should have the ability to discover previously unknown sub-communities from different social groups in a way to preserve privacy of participants in each group. In this paper, we present a middleware that runs on end-users' mobile phones to sanitize their profiles' data when released for generating referrals, such that computation of referrals continues over the sanitized version of their profiles' data. The proposed middleware is equipped with cryptography protocols to facilitate private discovery of sub-communities from the sanitized version of participants' profiles in a university scenario. Location data are added to participants' profiles to improve the awareness of surrounding sub-communities, so the offered referrals can be filtered based on adjacent locations for participant's location. We performed a number of different experiments to test the efficiency and accuracy of our protocols. We also developed a formal model for the tradeoff between privacy level and accuracy of referrals. As supported by the experiments, the sub-communities were correctly identified with good accuracy and an acceptable privacy level.
|
|
| 1178. |
- Elragal, Ahmed, et al.
(author)
-
The effect of implementing ERP systems on business performance : An exploratory case-study
- 2010
-
In: Knowledge Management and Innovation. - : International Business Information Management Association (IBIMA). - 9780982148945 ; , s. 1296-1314
-
Conference paper (peer-reviewed)abstract
- There is currently plenty of research concerning the effect of Enterprise Resource Planning (ERP) on business performance. Previous research has shown a mixed relationship between ERP and business performance where some suggested that ERP improves performance while others found that it does not. This paper investigates this topic by analyzing a detailed case-study consisting of an Egyptian SME, as a branch of a multinational company. The results indicate in general many benefits in business performance were achieved after implementing the ERP as reported by many users, but have also shown that few benefits previously linked to ERP were not fully achieved.
|
|
| 1179. |
- Elsayed, Mohamed Hammad, et al.
(author)
-
Hydrophobic and Hydrophilic Conjugated Polymer Dots as Binary Photocatalysts for Enhanced Visible-Light-Driven Hydrogen Evolution through Forster Resonance Energy Transfer
- 2021
-
In: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 13:47, s. 56554-56565
-
Journal article (peer-reviewed)abstract
- Organic semiconducting polymers exhibited promising photocatalytic behavior for hydrogen (H-2) evolution, especially when prepared in the form of polymer dots (Pdots). However, the Pdot structures were formed using common nonconjugated amphiphilic polymers, which have a negative effect on charge transfer between photocatalysts and reactants and are unable to participate in the photocatalytic reaction. This study presents a new strategy for constructing binary Pdot photocatalysts by replacing the nonconjugated amphiphilic polymer typically employed in the preparation of polymer nanoparticles (Pdots) with a low-molecular-weight conjugated polyelectrolyte. The as-prepared polyelectrolyte/hydrophobic polymer-based binary Pdots truly enhance the electron transfer between the Pt cocatalyst and the polymer photocatalyst with good water dispersibility. Moreover, unlike the nonconjugated amphiphilic polymer, the photophysics and mechanism of this photocatalytic system through time-correlated single-photon counting (TCSPC) and transient absorption (TA) measurements confirmed the Forster resonance energy transfer (FRET) between the polyelectrolyte as a donor and the hydrophobic polymer as an acceptor. As a result, the designated binary Pdot photocatalysts significantly enhanced the hydrogen evolution rate (HER) of 43 900 mu mol g(-1) h(-1) (63.5 mu mol h(-1), at 420 nm) for PTTPA/PFTBTA Pdots under visible-light irradiation.
|
|
| 1180. |
- Elsayed, Mohamed Hammad, et al.
(author)
-
Visible-light-driven hydrogen evolution using nitrogen-doped carbon quantum dot-implanted polymer dots as metal-free photocatalysts
- 2021
-
In: Applied Catalysis B: Environmental. - : Elsevier BV. - 0926-3373. ; 283
-
Journal article (peer-reviewed)abstract
- Given the photocatalytic properties of semiconducting polymers and carbon quantum dots (CQDs), we report a new structure for a metal-free photocatalytic system with a promising efficiency for hydrogen production through the combination of an organic semiconducting polymer (PFTBTA) and N-doped carbon quantum dots (NCQDs) covered by PS-PEGCOOH to produce heterostructured photocatalysts in the form of polymer dots (Pdots). This design could provide strong interactions between the two materials owing to the space confinement effect in nanometer-sized Pdots. Small particle size NCQDs are easy to insert inside the Pdot, which leads to an increase in the stability of the Pdot structure and enhances the hydrogen evolution rate by approximately 5-fold over that of pure PFTBTA Pdots. The photophysics and the mechanism behind the catalytic activity of our design are investigated by transient absorption measurement, demonstrating the role of NCQDs to enhance the charge separation and the photocatalytic efficiency of the PFTBTA Pdot.
|
|
