10,230 research outputs found
Implementation in Altran for Rational Function Integration and Polynomial Factorization
No full textTitle: Implementation in Altran for Rational Function Integration and Polynomial Factorization , Author: Mahmoud M. Makhlouf, Location: ThodeThis project is a study involving the application of the ALTRAN system to rational function integration. A discussion and the implementation of two methods are given, one by Hermite [HER 12] and a second by Horowitz [HOR 70]. Included is a brief discussion of the integration of the transcendental part over the rational field using polynomial factorization over the integers. Furthermore, an extension for multivariate rational function integration and
multivariate polynomial factorization is included.ThesisMaster of Science (MS
Development of Polyanionic Compounds for Li-, Na-, and K-ion Batteries
No full textEnergy storage and conversion systems are regarded as the most important technologies offering sustainable alternatives to address the immense and continuous increase in electrical energy consumption in world (1-3). Batteries are one of the most determining energy storage devices thanks to their wide range of possible applications such as portable devices, electric vehicles, grid storage, etc. The electrodes are the main and determinant units participating in the electrochemical reactions in a battery upon cycling. The performance of electrode materials in Li-ion, Na-ion and K-ion batteries depend not only on their chemical composition but also on their microstructure.
Polyanionic compounds based cathode materials appear to constitute first-rank candidates for green and sustainable electrode materials for secondary batteries. Here, one-step synthesis route using spray is used to produce highly homogeneous, crystalline and impurity-free phosphate-carbon composite electrode materials for Li-ion, Na-ion and K-ion batteries. The electrochemical performance of electrode materials has been enhanced by the addition of the carbon sources/allotropes during the material preparation (3-7).
References
1. A. Mahmoud, M. Al Daroukh, M. Lipinska-Chwalek, M. Luysberg, F. Tietz, R.P. Hermann, Solid State Ionics, 312 (2017), pp. 38-43. https://doi.org/10.1016/j.ssi.2017.10.003
2. C.M. Berger, A. Mahmoud, R.P. Hermann, W. Braun, E. Yazhenskikh, Y.J. Sohn, N.H. Menzler, O. Guillon, M. Bram, J. Am. Ceram. Soc. (2016), https://doi.org/10.1111/jace.14439
3. B. Vertruyen, N.Eshraghi, C. Piffet, J. Bodart, A. Mahmoud, F. Boschini. Materials 11 (2018) 1076. https://doi.org/10.3390/ma11071076.
4. N. Eshraghi, S. Caes, A. Mahmoud, R. Cloots, B. Vertruyen, F. Boschini. Electrochimica Acta 228 (2017) 319–324. https://doi.org/10.1016/j.electacta.2017.01.026
5. J. Bodart, N. Eshraghi, T. Carabin, B. Vertruyen, R. Cloots, F. Boschini, A. Mahmoud. J. Power Sources 480 (2020) 22905. https://doi.org/10.1016/j.jpowsour.2020.229057
6. A. Mahmoud, S. Caes, M. Brisbois, R. P. Hermann, L. Berardo, A. Schrijnemakers, C. Malherbe, G. Eppe, R. Cloots, B. Vertruyen, F. Boschin. J. Solid State Electrochemistry 22 (2018) 103-112. https://doi.org/10.1007/s10008-017-3717-x
7. M. Brisbois, S. Caes, M. T. Sougrati, B. Vertruyen, A. Schrijnemakers, R. Cloots, N. Eshraghi, R. P Hermann, A. Mahmoud, F. Boschini. Solar Energy Materials and Solar Cells 148 (2016) 67–72. https://doi.org/10.1016/j.solmat.2015.09.00
Application of demographic analysis for assessing effects of pesticides on the predatory mite, Phytoseiulus persimilis (Acari: Phytoseiidae)
No full textAhmed, Mahmoud M., Abdel-Rahman, Hala R., Abdelwines, Mohammed A. (2021): Application of demographic analysis for assessing effects of pesticides on the predatory mite, Phytoseiulus persimilis (Acari: Phytoseiidae). Persian Journal of Acarology 10 (23): 281-298, DOI: 10.22073/pja.v10i3.6675
Strategies for the development of high-performance electrode materials for sustainable Li-, Na-, and K-ion batteries
No full textBatteries have become essential in tackling global warming and energy security. Rechargeable Li-ion technology, by having the highest energy density of any such device, is considered as the battery of choice for electric vehicles and large-scale smart grids. However, lithium ion batteries cannot stand alone to fulfill future needs; therefore, it is urgent to develop new energy storage devices with high safety, lower cost, high energy density and green sustainable to realize mobiles and large-scale applications. Due to the high abundance of sodium and potassium, Na-ion batteries and K-ion batteries have recently emerged as highly promising candidates. In this seminar, we present one-step preparation of composite materials using spray-drying or hydrothermal synthesis routes, two techniques which offer easy scaling-up of production. The objective of this presentation is to demonstrate that the addition of the carbon sources/allotropes during the material preparation allows to control the particle morphology and ensures intimate mixture of the active material and conductive carbon that enhance the electrochemical performance of the electrode materials for Li-, Na- and K-ion batteries [1-6].
References
1- N. Eshraghi, A. Mahmoud, F. Boschini, R. Cloots, EP Patent EP2 (2020) 019, 081, 384.
2- N. Eshraghi, S. Caes, A. Mahmoud, R. Cloots, B. Vertruyen, F. Boschini, Electrochimica Acta, 228 (2017) 319–324.
3. B. Vertruyen, N.Eshraghi, C. Piffet, J. Bodart, A. Mahmoud, F. Boschini. Materials 11 (2018) 1076.
4- C. Karegeya, A. Mahmoud, R. Cloots, B. Vertruyen, F. Boschini, Electrochimica Acta 250 (2017) 49–58.
5. C. Karegeya, A. Mahmoud, F. Hatert, B. Vertruyen, R. Cloots, P-E. Lippens, F. Boschini. J. Power Sources 388 (2018) 57-64.
6. A. Mahmoud, C. Karegeya, M. T. Sougrati, J. Bodart, B. Vertruyen, R. Cloots, P-E. Lippens, F. Boschini. ACS Applied Materials and interfaces 10 (40) (2018) 34202-34211
Photochemistry of some cyclopentadienyl carbonyl complexes of chromium, molybdenum, tungsten, iron and ruthenium isolated in frozen gas matrices at 12K
No full textPhotochemical processes of a variety of cyclopentadienyl transition metal carbonyl complexes of general formula (η5-C5H5)M(CO)nR(n = 3, M = Cr, Mo, W; n = 2, M = Fe, Ru; R = alkyl), (η5-C5H5)M(CO)nX (n = 3, M = Mo, W; X = Cl, AsR2, SbR2; n = 2, M = Fe, Ru: X = Cl) and (η5-C5H5)2Fe2(CO)4have been studied for the first time at 12K using primarily infrared spectroscopy together with 13CO labelling.Photoejection of CO from (η5-C5H5)M(CO)3R complexes (M = Cr, Mo, W; R = CH3, CF3, COCF3) results in the formation of the 16-electron species (η5-C5H5)M(CO)2R. Evidence is also found for α-H and α-F elimination in the complexes (η5-C5H5)Cr(CO)3CH3 and (η5-C5H5)Mo(CO)3CF3 respectively, and for the fluoroalkyl migration to the metal in the complex (η5-C5H5)Mo(CO)3COCF3.Photolysis of (η5-C5H5)M(CO)3H complexes (M = Cr, Mo, W) in Ar and CH4 matrices generates the16-electron species (η5-C5H5)M(CO)2H. The reactivity of these species is apparent in their reactions with N2and C2H4 to produce (η5-C5H5)M(CO)2(N2)H and (η5-C5H5)M(CO)2(C2H4)H derivatives. In CO matrices the observation of the radicals (η5-C5H5)M(CO)3͘ and HCȮ is indicative of photo-induced metal-hydrogen bond cleavage. Irradiation of trans-(η5-C5H5) W(C0)2(C2H4)H in CH4 matrices causes trans ⇌ cis isomerisation, followed by insertion of C2H4 into the W-H bond to generate the 16-electron species (η5-C5H5)W(CO)2C2H5.Irradiation of (η5-C5R5̍)M(CO)3 alkyl complexes (M = Mo, W; R' = H, CH3) results in the formation of the 16-electron intermediates (η5-C5R5̍)M(CO)2alkyl. For alkyl complexes with β-hydrogens, thermal and photochemical 6-elimination reactions led to the conversion of (η5-C5R5̍)M(CO)2 alkyl species into the olefin-hydrides (η5-C5R5̍)M(CO)2(olefin)H. Photolysis of the (η5-C5H5)W(CO)3(η1-R) complexes (R = C3H5, CH2C6H5), led to CO dissociation and η1 ⇌ η3 isomerisation.Direct evidence for CO dissociation as a primary photoprocess for (η5-C5H5)M(CO)2R complexes (M = Fe, Ru; R = CH3, C5H5) was afforded by trapping the 16-electron species (η5-C5H5)Ru(CO)CH3 in a CH4 matrix. Photolysis of (η5-C5H5)M(CO)2C2H5 complexes in CH4 matrices afforded (η5-C5H5)Fe(CO)2H and (η5-C5H5)Ru(CO)2H together with(η5-C5H5)Ru(CO)(C2H4)H, i.e. β-elimination. In CO matrices ring-slippage products, (η3-C5H5)M(CO)3R, were formed.</p
A study on the relationship between microstructure and electrochemical performance of the phosphate electrode materials for Li-, Na-, and K-ion batteries
No full textOne of the main challenges of energy storage devices is the development of cheap and eco-friendly battery systems with high safety and high energy density. Battery is the best choice to store electricity in the form of chemical energy when considering the flexibility and constitute the limiting components in shift from petrol powered to electric vehicles, while also the use of the more renewable energy on the grid. Since the nineties, lithium-ion batteries (LIBs) have become one of the dominant technologies, however, lithium ion batteries cannot stand alone to fulfill future needs. Due to the high abundance of sodium and potassium, Na-ion batteries and K-ion batteries have recently emerged as highly promising candidates.
Electrode materials present the key component for the development for the new generation of the rechargeable batteries. This seminar will focus on the design, synthesis and characterization of high capacity phosphate electrode materials for Alkali-ion batteries with special attention paid to the control of microstructure as a tool to optimize their electrochemical properties. The materials have been prepared using facile, inexpensive and suitable synthesis methods (hydrothermal and spray drying) for powders with high homogeneity, leading to excellent electrochemical properties (1-6).
References:
1. J. Bodart, N. Eshraghi, T. Carabin, B. Vertruyen, R. Cloots, F. Boschini, A. Mahmoud, J. Power Sources 480 (2020) 22905.
2- N. Eshraghi, S. Caes, A. Mahmoud, R. Cloots, B. Vertruyen, F. Boschini, Electrochimica Acta, 228 (2017) 319–324.
3- C. Karegeya, A. Mahmoud, R. Cloots, B. Vertruyen, F. Boschini, Electrochimica Acta 250 (2017) 49–58.
4. C. Karegeya, A. Mahmoud, F. Hatert, B. Vertruyen, R. Cloots, P-E. Lippens, F. Boschini. J. Power Sources 388 (2018) 57-64.
5. A. Mahmoud, C. Karegeya, M. T. Sougrati, J. Bodart, B. Vertruyen, R. Cloots, P-E. Lippens, F. Boschini. ACS Applied Materials and interfaces 10 (40) (2018), 34202-34211.
6. A. Mahmoud, S. Caes, M. Brisbois, R. P. Hermann, L. Berardo, A. Schrijnemakers, C. Malherbe, G. Eppe, R. Cloots, B. Vertruyen, F. Boschin J Solid State Electrochem. 22 (2018) 103-112
Towards high energy, sustainable and safe rechargeable batteries
No full textBatteries have become essential in tackling global warming and energy security. Rechargeable Li-ion technology (LIBs), by having the highest energy density of any such device, is mainly dominating in the fields of consumer electronics and electric vehicles. Given the high demand and fast-growing market, Li-ion batteries cannot stand alone to fulfill all future needs. This has boosted the exploration and discovery of novel electrochemical energy conversion and storage technologies based on more abundant, cheap, and accessible materials with the lowest environmental impact. Therefore, it is urgent to develop new sustainable and affordable energy storage devices with high safety, lower cost, and high energy density to realize mobiles and large-scale applications. As alternatives, battery chemistries based on more abundant elements (e.g., Na, K, Zn) have received extensive attention (1-5). Different approaches to boost the practical energy density and cycle life of electrode materials for next-generation rechargeable batteries will be presented. The optimization of the synthesis of different active electrode materials is reported. Different strategies are used to further stabilize and boost the electrochemical performance. References:
1- E. Roex, F. Boschini, V. Delaval, A. Schrijnemakers, R. Cloots, A. Mahmoud. Journal of Electroanalytical Chemistry 929 (2023) 117133
2- C. Piffet, B. Vertruyen, F. Hatert, R. Cloots, F. Boschini, A. Mahmoud. Journal of Energy Chemistry 65 (2022) 210-218.
3- A. Aqil, C. Jérôme, F. Boschini, A. Mahmoud. Batteries and Supercaps 4 (2021) 374.
4- R. Essehli, K. Maher, M. R. Amin, A. Abouimrane, A. Mahmoud, N. Muralidharan, R. K. Petla, H. Ben Yahia, and I. Belharouak. ACS Applied Materials Interfaces 12 (2020) 41765–41775.
5- J. Bodart, N. Eshraghi, T. Carabin, B. Vertruyen, R. Cloots, F. Boschini and A. Mahmoud. Journal of Power Sources 480 (2020) 229057
Electrode Materials for Li/Na-ion Batteries: Improving Electrochemical Performance Through Carbon Addition During Synthesis
No full textLithium-ion batteries (LIBs) have outperformed other rechargeable battery systems since 1980 and advances in LIBs technology have improved living conditions around the globe. However, Li-ion batteries face many challenges and limitations. Na-ion batteries are considered to be an alternative to Li-ion batteries owing to the natural abundance of sodium. New electrode materials are required to increase the energy density of Li/Na-ion batteries. However, their electronic conductivity usually has to be improved through the preparation of composite powders ensuring intimate contact between the active material and conductive carbon. In this presentation, we report on the one-step synthesis of composite materials using spray-drying or hydrothermal synthesis routes, two techniques which are easily up-scalable[1-6].
In order to evidence the effect of the carbon on the microstructural and electrochemical properties of the prepared materials by a spray-drying [1-3] or hydrothermal methods [4-6]. The crystal and local structures were analyzed by combining XRD and 57Fe Mössbauer spectroscopy. The morphological properties were characterized by SEM and TEM (Figure 1). The carbon content was determined by TG/TDA and carbon analyzer. The electrochemical properties were studied by impedance spectroscopy and galvanostatic cycling in lithium and sodium cells. The reaction mechanism during cycling was investigated by combining operando X-ray diffraction and 57Fe Mössbauer spectroscopy.
References
1- A. Mahmoud, S. Caes, M. Brisbois, R.P. Hermann, L. Berardo, A. Schrijnemakers, C. Malherbe, G. Eppe, R. Cloots, B. Vertruyen, F. Boschini. J. Solid State Electrochemistry 22 (1) (2018) 103-112.
2- N. Eshraghi, S. Caes, A. Mahmoud, R. Cloots, B. Vertruyen, F. Boschini. Electrochimica Acta 228 (2017) 319-324.
3. B. Vertruyen, N.Eshraghi, C. Piffet, J. Bodart, A. Mahmoud, F. Boschini. Materials 11 (2018) 1076.
4- C. Karegeya, A. Mahmoud, R. Cloots, B. Vertruyen, F. Boschini. Electrochimica Acta 250 (2017) 49-58.
5. C. Karegeya, A. Mahmoud, F. Hatert, B. Vertruyen, R. Cloots, P-E. Lippens, F. Boschini. J. Power Sources 88 (2018) 57-64.
6. A. Mahmoud, C. Karegeya, M. T. Sougrati, J. Bodart, B. Vertruyen, R. Cloots, P-E. Lippens, F. Boschini. ACS Applied Materials and interfaces 10 (2018) 34202-34211
Development the iron- and vanadium-based electrode materials for rechargeable Li/Na-ion batteries
No full textLithium-ion batteries have been widely applied as a power source for portable and stationary energy storage systems. Na-ion batteries are considered to be an alternative to Li-ion batteries owing to the natural abundance of sodium. New electrode materials are required to increase the energy density of Li/Na-ion batteries. In this study, we report on the one-step synthesis of composite materials using spray-drying or hydrothermal synthesis routes, two techniques which offer easy scaling-up of production. The objective of this presentation is to show that the addition of the carbon sources during the synthesis leads to control the particles size and ensures intimate contact between the active material and conductive carbon that enhance the electrochemical performance [1-6].
In order to study the effect of the carbon on the structural, morphological and electrochemical properties of the prepared materials by a spray-drying [1-3] or hydrothermal methods [4-6]. The crystal and local structure were analyzed by XRD and 57Fe Mössbauer spectroscopy. The morphological properties were characterized by SEM and TEM. The carbon content was determined by TG/TDA and carbon analyzer. The electrochemical properties were studied by impedance spectroscopy and galvanostatic cycling in lithium cells. The mechanism of the first discharge-charge cycle was investigated by combining operando X-ray diffraction and 57Fe Mössbauer spectroscopy
References
1- A. Mahmoud, S. Caes, M. Brisbois, R.P. Hermann, L. Berardo, A. Schrijnemakers, C. Malherbe, G. Eppe, R. Cloots, B. Vertruyen, F. Boschini, J. Solid State Electrochemistry (2017) 1–10.
2- N. Eshraghi, S. Caes, A. Mahmoud, R. Cloots, B. Vertruyen, F. Boschini, Electrochimica Acta, 228 (2017) 319–324.
3. B. Vertruyen, N.Eshraghi, C. Piffet, J. Bodart, A. Mahmoud, F. Boschini. Materials 11 (2018) 1076.
4- C. Karegeya, A. Mahmoud, R. Cloots, B. Vertruyen, F. Boschini, , Electrochimica Acta 250 (2017) 49–58.
5. C. Karegeya, A. Mahmoud, F. Hatert, B. Vertruyen, R. Cloots, P-E. Lippens, F. Boschini. J. Power Sources. 388 (2018) 57-64.
6. A. Mahmoud, C. Karegeya, M. T. Sougrati, J. Bodart, B. Vertruyen, R. Cloots, P-E. Lippens, F. Boschini. ACS Applied Materials and interfaces, (2018) 10.1021/acsami.8b10663
Manuela Gallerani e Rita Casadei, Le latitudini della Pedagogia. Dialogo a due voci tra Occidente e Oriente. Loffredo Editore. University Press, Napoli, 2012.
No full textIl libro è suddiviso in due parti: la prima parte, scritta da M. Gallerani, si concentra sulla pedagogia occidentale. La Seconda parte invece, scritta da R. Casadei si concentra sulla dimensione educativa giapponese
- …
