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French version available in IDRC Digital Library: Kimaki jiko

The South African electricity supply industry (ESI) is dominated by a state-owned and vertically integrated utility, Eskom, which ranks seventh in the world in terms of size and electricity sales; 92% of electricity is generated from coal. Data is presented to provide a snapshot of the current situation (2002). The paper examines the rationale for reform and restructuring of the South African ESI.

A comprehensive model was developed to simulate gasification of pine sawdust in the presence of both air and steam. The proposed model was built upon the premise of an existing Aspen Plus-based biomass gasification model with select improvements. These include the addition of a temperature-dependent pyrolysis model, an updated hydrodynamic model, more extensive gasification kinetics and the inclusion of tar formation and reaction kinetics. The Aspen Plus process simulator was used in combination with a more extensive Fortran subroutine to appropriately model a Bubbling Fluidized Bed (“BFB”) gasifier. The validity of the model was compared on two fronts: Firstly, the accuracy of the model’s predictions in comparison with the actual experimental results; and secondly, the relative accuracy of the model prediction in comparison to the original base-model.

Dielectric and anelastic spectroscopies are complementary techniques and their combination allows valuable information to be obtained in the field of multifunctional materials. Whereas the dielectric spectroscopy measures the dielectric susceptibility ?(?,T) and it is sensitive to fluctuations of electric dipoles, the anelastic spectroscopy measures the elastic compliance or elastic susceptibility s(?,T) and it is sensitive to fluctuations of elastic dipoles. Both susceptibilities are complex, their immaginary part being due to the delayed response of the mobile defects coupled to the electric field/stress. The great advantage of using a combination of both techniques is that the anelastic measurements are insensitive to free charges, therefore it is possible to measure the dynamics of ions also in the presence of free charges. Two main types of investigations have been pursued by the combination of these techniques: the study of structural phase transitions and the study of microscopic mechanisms associated with the presence of defects, both important for the knowledge and development of multifunctional materials. We have applied this approach for different functional materials with perovskite framework: multiferroic, ferroelectric and relaxor ferroelectric ceramics, and organic-inorganic perovskite photovoltaics. Thanks to the combination of the two spectroscopies, it has been possible to probe more accurately the structural transitions involving the antiferrodisortive tilt modes of the octahedra in PZT [1] and NBT-BT [2]. It was also possible to evidence incipient phase separation in lead titanate-based multiferroics [3]. Moreover, since the elastic response is insensitive to free charges, it has been used to probe the piezoelectric response even in unpoled ceramics [4] and for the study of coexisting ferroelectric and metallic states [5]. The combination of the two techniques allowed also new features to be revealed on the reorientation dynamics of the organic molecules in MAPbI3 photovoltaic organic-inorganic perovskites and the hindrance of their ferroelectric order by coupling with the tilt modes [6]. 1. F. Cordero, F. Trequattrini, F. Craciun, C. Galassi, Phys. Rev. B, 87 (2013) 094108 2. F. Cordero, F. Craciun, F. Trequattrini, et al., Phys. Rev. B, 81 (2010) 144124 3. F. Craciun, F. Cordero, B. Vasile, et al., Phys. Chem. Chem. Phys., 20 (2018) 14652 4. F. Cordero, F. Craciun, F. Trequattrini, C. Galassi, Phys. Rev. B, 93 (2016) 174111 5. F. Cordero, F. Trequattrini, F. Craciun, et al., Phys. Rev. B, 99 (2019) 064106 6. F. Cordero, F. Craciun, F. Trequattrini, et al., J. Phys. Chem. Lett., 9 (2018) 4401

With an ever-growing population, global energy demand increases, thereby contributing to the depletion of fossil resources and their limited reserves. Thereby, to lessen the environmental damage caused by fossil fuels, there has been a surge of interest in developing and producing biofuels from renewable feedstocks, such as microbial lipids. Typically, they are derived via a biochemical process using liquid hydrolysates obtained from forestry residues as a substrate. However, microbial lipid production using hydrolysates presents numerous challenges, including the need for a strain that can accumulate high lipid titers, consume five-carbon sugars (C5), and tolerate inhibitory compounds (e.g., furans, phenols, and organic acids), among others. Out of several microorganisms, Rhodosporidium toruloides, an oleaginous yeast, could be a potential alternative to produce lipids. It is known to accumulate lipids up to 70% of its dry cell weight, use different carbon sources, and tolerate several inhibitory compounds. In this sense, the current thesis explores the ability of Rhodosporidium toruloides as a bio-factory to produce microbial lipids using C5 and C6 wood hydrolysates as a culture media. Different R. toruloides strains were screened, and R. toruloides-1588 was determined to have the highest lipid accumulation of 35%. Following the culture media, carbon to nitrogen ratio, use of lipid inducers, and sugar concentration optimization, the lipid accumulation increased from 35% to 57.14%, with 95% and 80% of glucose and xylose utilization in hydrolysates, respectively. Likewise, palmitic, stearic, and oleic fatty acids were the most prominently on the produced lipids. Finally, R. toruloides-1588 demonstrates the capacity to grow, accumulate lipids, and transform furfural into furfuryl alcohol and 2-furoic acid. The strain was also assessed for its ability to tolerate inhibitory compounds, such as 5-hydroxymethyl furfural, vanillin, syringaldehyde, levulinic acid, ferulic acid, acetic acid, vanillic acid, and ...

This Milestone, namely M3.3, is part of Task 3.3 “Downscaling of future climate projections at the case-study scale and their transfer to the Partners”. The aim of M3.3 is to outline the results of the climate change evaluation over the investigated pilot sites. For the future projections of the climate variables (precipitation and temperature), the data provided by EURO-CORDEX initiative under two emission scenarios (RCP4.5 and RCP8.5) are used. The main information on the pilot sites, available data, analyses and results are presented. The data are freely downloadable from the web repository https://doi.org/10.5281/zenodo.7247977. This project is part of the PRIMA Programme supported by the European Union's Horizon 2020 Research and Innovation Programme under Grant Agreement No 1923.

"A report prepared to review the wind power potential of Eastern Africa and assess its applicability for waterpumping" ; Photocopy ; The viability of wind power as a means of pumping water in Eastern Africa and Botswana is studied. Discusses the activities of several research groups and evaluates projects in terms of feasibility and implementation. Includes a brief state-of-the-art review of wind development programmes in Europe.

This work has been developed under the AGROinLOG Project, “Demonstration of innovative integrated biomass logistics centres for the Agro-industry sector in Europe”. An Integrated Biomass Logistics Center (IBLC), is based on the introduction of new production chains into existing agro-industries by using new biomass feedstock. The AGROinLOG Project has dedicated great attention to investigate the potential of cereal chaff as a valuable resource.Chaff is the fine fraction of the thrashing residues, not usually collected. Chaff is made up of glumes, seed husks, rachis and the tinner part of the cereal stems, whole and cracked kernels, as well as weed seeds.Currently there are several mechanical solutions available on the market for chaff recovery, and others are still at prototype stage, but theyare not so common and very often unknown to the farmers.So far, the literature reportsfew cases of chaff collection with the specific purpose of weed seeds removal, but it still lacks specificexperiments on these machinesintentionally used for biomass collection.For this reason, during the Project AGROinLOG a series of large field tests were performed using an independent scientific approach with different kind of chaff harvesting technologiesin France, Sweden and Italy from 2017 to 2019.The present study collects the results of these activities with the aim to fill that gap and provide deeper understanding in the possibility to enhance the current cereal harvesting method, in order to improve the quantity of biomass collected by including the chaff. Proceedings of the 29th European Biomass Conference and Exhibition, 26-29 April 2021, Online, pp. 62-68

The recent trend of increasing share of renewable energy sources (RES) in the generation mix has necessitated new operational and planning studies because of the high degree of uncertainty and variability of these sources. RES such as solar photovoltaic and wind generation are not dispatchable, and when there is excess energy supply during off-peak hours, RES curtailment is required to maintain the demand-supply balance. Furthermore, RES are intermittent resources which have introduced new challenges to the provision of ancillary services that are critical to maintaining the operational reliability of power systems. Energy storage systems (ESS) play a pivotal role in facilitating the integration of RES to mitigate the aforementioned issues. Therefore, there is a growing interest in recent years to examine the potential of ESS in the future electricity grids. This research focuses on developing market participation and investment planning frameworks for ESS considering different ownership structures. First, a novel stochastic planning framework is proposed to determine the optimal battery energy storage system (BESS) capacity and year of installation in an isolated microgrid using a novel representation of the BESS energy diagram. A decomposition-based approach is proposed to solve the problem of stochastic planning of BESS under uncertainty. The optimal decisions minimize the net present value of total expected costs over a multi-year horizon considering optimal BESS operation using a novel matrix representing BESS energy capacity degradation. The proposed approach is solved in two stages as mixed integer linear programming (MILP) problems; the optimal ratings of the BESS are determined in the first stage, while the optimal installation year is determined in the second stage. Extensive studies considering four types of BESS technologies for deterministic, Monte Carlo Simulations, and stochastic cases are presented to demonstrate the effectiveness of the proposed approach. The thesis further studies the ...