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Field evaluation of the attractiveness of zingerone and cuelure on the main <i>Dacus </i>(Diptera: Tephritidae) species in Mozambique
No full textTechnical Expertise Report n°exp-393, 5/11/2021 - Applicant: Gevelinzicht ingenieur-architecten, Bolwerkstraat 22, 2018 Antwerpen, 29/10/2021
No full textUrban ozone formation and sensitivities to volatile chemical products, cooking emissions, and NOx upwind of and within two Los Angeles Basin cities
Get PDFVolatile chemical products (VCPs) and other non-traditional anthropogenic sources, such as cooking, contribute substantially to the volatile organic compound (VOC) budget in urban areas, but their impact on ozone formation is less certain. This study employs Lagrangian box modeling and sensitivity analyses to evaluate ozone response to sector-specific VOC and nitrogen oxide (NOx) emissions in two Los Angeles (LA) Basin cities during the summer of 2021. The model simulated the photochemical processing and transport of temporally and spatially gridded emissions from the FIVE-VCP-NEI17NRT inventory and accurately simulates the variability and magnitude of O3, NOx, and speciated VOCs in Pasadena, CA. VOC sensitivity analyses show that anthropogenic VOCs (AVOC) enhance the mean daily maximum 8 h average ozone in Pasadena by 13 ppb, whereas biogenic VOCs (BVOCs) contribute 9.4 ppb. Of the ozone influenced by AVOCs, VCPs represent the largest fraction at 45 %, while cooking and fossil fuel VOCs are comparable at 26 % and 29 %, respectively. NOx sensitivity analyses along trajectory paths indicate that the photochemical regime of ozone varies spatially and temporally. The modeled ozone response is primarily NOx-saturated across the dense urban core and during peak ozone production in Pasadena. Lowering the inventory emissions of NOx by 25 % moves Pasadena to NOx-limited chemistry during afternoon hours and shrinks the spatial extent of NOx saturation towards downtown LA. Further sensitivity analyses show that using VOCs represented by a separate state inventory requires steeper NOx reductions to transition to NOx sensitivity, further suggesting that accurately representing VOC reactivity in inventories is critical to determining the effectiveness of future NOx reduction policies
Monitoring carbon stocks and tree diversity in the tropical forest landscape of Tshopo province, Democratic Republic of the Congo
Get PDFThe Kivu Citizen Observer network: creating and disseminating knowledge about natural hazard disasters to improve Disaster Risk Reduction in non-surveyed regions
No full textMark(et)ing Expertise : the Goldsmith-engraver in the Low Countries and the use of House-Marks
No full textThis article investigates the role of signatures, monograms, and house marks in the early Netherlandish print market
Evaluating present-day and future impacts of agricultural ammonia emissions on atmospheric chemistry and climate
Get PDFAgricultural practices are a major source of ammonia (NH3) in the atmosphere, which has implications for air quality, climate, and ecosystems. Due to the rising demand for food and feed production, ammonia emissions are expected to increase significantly by 2100 and would therefore impact atmospheric composition such as nitrate (NO3-) or sulfate (SO2-4) particles and affect biodiversity from enhanced deposition. Chemistry–climate models which integrate the key atmospheric physicochemical processes with the ammonia cycle represent a useful tool to investigate present-day and also future reduced nitrogen pathways and their impact on the global scale. Ammonia sources are, however, challenging to quantify because of their dependencies on environmental variables and agricultural practices and represent a crucial input for chemistry–climate models. In this study, we use the chemistry–climate model LMDZ–INCA (Laboratoire de Météorologie Dynamique–INteraction with Chemistry and Aerosols) with agricultural and natural soil ammonia emissions from a global land surface model ORCHIDEE (ORganising Carbon and Hydrology In Dynamic Ecosystems), together with the integrated module CAMEO (Calculation of AMmonia Emissions in ORCHIDEE), for the present-day and 2090–2100 period under two divergent Shared Socioeconomic Pathways (SSP5-8.5 and SSP4-3.4). Future agricultural emissions under the most increased level (SSP4-3.4) have been further exploited to evaluate the impact of enhanced ammonia emissions combined with future contrasting aerosol precursor emissions (SSP1-2.6 – low emissions; SSP3-7.0 – regionally contrasted emissions). We demonstrate that the CAMEO emission set enhances the spatial and temporal variability in the atmospheric ammonia in regions such as Africa, Latin America, and the US in comparison to the static reference inventory (Community Emissions Data System; CEDS) when assessed against satellite and surface network observations. The CAMEO simulation indicates higher ammonia emissions in Africa relative to other studies, which is corroborated by increased current levels of reduced nitrogen deposition (NHx), a finding that aligns with observations in west Africa. Future CAMEO emissions lead to an overall increase in the global NH3 burden ranging from 59 % to 235 %, while the NO3- burden increases by 57 %–114 %, depending on the scenario, even when global NOx emissions decrease. When considering the most divergent scenarios (SSP5-8.5 and SSP4-3.4) for agricultural ammonia emissions, the direct radiative forcing resulting from secondary inorganic aerosol changes ranges from −114 to −160 mW m−2. By combining a high level of NH3 emissions with decreased or contrasted future sulfate and nitrate emissions, the nitrate radiative effect can either overcompensate (net total sulfate and nitrate effect of −200 mW m−2) or be offset by the sulfate effect (net total sulfate and nitrate effect of +180 mWm-2). We also show that future oxidation of NH3 could lead to an increase in N2O atmospheric sources from 0.43 to 2.10 Tg N2O yr−1 compared to the present-day levels, representing 18 % of the future N2O anthropogenic emissions. Our results suggest that accounting for nitrate aerosol precursor emission levels but also for the ammonia oxidation pathway in future studies is particularly important to understand how ammonia will affect climate, air quality, and nitrogen deposition
Carbon and biodiversity restoration potential in an artificial savanna in the Democratic Republic of the Congo
Get PDFA large share of the global forest restoration potential is situated in unstable mesic African savannas, contributing about 23% to the global mismatch between potential and actual terrestrial carbon stocks. However, uncertainty on Central African forest recovery rates impedes science-informed implementation of forest restoration efforts. Here, we quantify the forest restoration success of 17 years of fire exclusion within a mesic artificial savanna patch in the Kongo Central province of the Democratic Republic of the Congo. Since 2005, the local community of the Manzonzi village has conserved an 88-ha artificial savanna with support from World Wildlife Fund. In 2010, we established 101 permanent plots (total area of 40.4 ha) and remeasured them (at the threshold of 10 cm DBH) in 2014 and 2022, by considering two species categories: savanna and forest specialists. Between 2010 and 2022, mean stem density switched from 122.3 ± 9.0 to 27.0 ± 3.8 tree/ha and from 45.8 ± 7.5 to 178.6 ± 10.1 tree/ha for savanna specialists (e.g. Hymenocardia acida and Maprounea africana), and forest specialists (e.g. Xylopia aethiopica and Albizia adianthifolia) respectively. We found that aboveground carbon (AGC) recovery of forest specialist after 17 years was on average 11.9 ± 0.2 Mg C ha−1. Using a model fitted to the data, we predicted that AGC stocks take 110 ± 3 years to recover to 90% of AGC stocks in old-growth forests. Applying this recovery trajectory, we show that unstable , artificial savannas across DRC, Congo, and Angola have a total carbon uptake potential of 13.5 ± 1.6 Gt C by 2100. Species richness recovered to 33.1% after 17 years and we predicted a 90% recovery at 57 ± 1 years. In contrast, the recovery of species composition was much slower, with an estimated 90% recovery after 125 ± 3 years. We conclude that carbon and biodiversity recovery trajectories are indispensable to developing policies promoting forest restoration in artificial African savannas. However, more long-term, in situ monitoring efforts are needed to quantify variation in carbon and diversity recovery owing to resource availability (rainfall and soil fertility), prior vegetation and land-use history, and surrounding forest cover
Géologie et ressources naturelles en Afrique centrale, impact sociétal et développement durable.
No full textPaint Composition and Delamination Concerns in Ole Schwalbe’s Portrait of a Painting III, 1962
No full textThis study investigates the preservation challenges associated with Ole Schwalbe's Portrait of a Painting III (1962). The painting, an example of minimalist abstract constructivism, suffers from severe paint delamination. Analytical techniques such as SEM-EDX, THM-GC/MS, micro-Raman spectroscopy and FTIR have been used to examine the paint composition and identify the causes of instability. The results suggest that incomplete curing processes and oxidative degradation in the thickly applied black paint has caused zinc soap accumulation in the underlying zinc white preparation layer. The volume reduction of the upper layers, combined with a swelling of the lower, has contributed to the degradation observed. This research provides insights into the conservation of post-war abstract artworks