Portail des publications scientifiques IMT Mines Alès
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Analyzing the Impact of Low-Rank Adaptation for Cross-Domain Few-Shot Object Detection in Aerial Images
No full textInternational audienceThis paper investigates the application of LowRank Adaptation (LoRA) to small models for cross-domainfew-shot object detection in aerial images. Originally designedfor large-scale models, LoRA helps mitigate overfitting, makingit a promising approach for resource-constrained settings. Weintegrate LoRA into DiffusionDet, and evaluate its performanceon the DOTA and DIOR datasets. Our results show thatLoRA applied after an initial fine-tuning slightly improvesperformance in low-shot settings (e.g., 1-shot and 5-shot),while full fine-tuning remains more effective in higher-shotconfigurations. These findings highlight LoRA’s potential forefficient adaptation in aerial object detection, encouragingfurther research into parameter-efficient fine-tuning strategiesfor few-shot learning. Our code is available here: https://github.com/HichTala/LoRA-DiffusionDe
Environmental Evaluation of the Mining Industry, Proposal of a New Method: Mining Environmental Impact Assessment Methodology (MEIAM)
No full textInternational audienceThe Mining Environmental Impact Assessment Methodology (MEIAM) is developed to allow predicting environmental and human health impacts on mining projects. It combines both the chronic and the accidental sources of impacts, and that at all phases of the life cycle of the project, including the prospection and the after closure of the mine. The method is designed to address all environmental problems: groundwater, surface water, soil, air, fauna and flora. A case study to test the feasibility of MEIAM and to compare its outputs to the usual approach has been carried out for the Afema gold mine located in Côte d’Ivoire. The case study was restricted to the groundwater. The results of this implementation were compared with those obtained by using the matrices method in the EIA study of this mining project. The two methods led to different conclusions. Unlike the EIA study, MEIAM identifies and evaluates many pollution scenarios. In the EIA study the potential groundwater pollution scenario involving soils leaching and, working face (open pit borders) were not considered. In addition, the exploration phase was not considered in the EIA study. The present work concluded that the impact of groundwater pollution is high at the operation and the closure phases, while previous study indicated an average impact (for the few considered scenarios). For these high impacts, some measures have been proposed to protect groundwater resources. MEIAM better assesses the impact of pollution by considering the intrinsic parameters (geology, climate, initial state of the environmental component) of the mine site, the nature of the potential pollutants and feedbacks. It may therefore be of considerable value in mining projects
Understanding the Role of Temperature on the Dissolution Process of Alkali-Activated Slag: A Path to Enhanced Reactivity at Low Temperatures
No full textInternational audienceAlkali-Activated Materials (AAMs), particularly Ground Granulated Blast Furnace Slag (GGBS)-basedAlkali-Activated Slag (AAS), have emerged as a promising green alternative to cement-based binders dueto their lower carbon footprint and satisfactory mechanical properties at ambient temperatures. Withgrowing global emphasis on carbon neutrality and sustainable infrastructure, the deployment of low-carbonalternatives like AAS in all climate zones is becoming increasingly critical. However, the limited reactivityof AAS at low temperatures (5 to 10°C), especially in early ages, remains a major barrier to its large-scaleapplication in colder regions. These temperature ranges, while not extreme, are very common in Europeand parts of Asia for several months of the year, making this issue particularly relevant for real-worldimplementation. Current solutions involve maintaining ambient temperatures on construction sites usingwarm sheds and electric blankets. These measures, although effective, are costly and energy-intensive,thereby negating the CO₂ reduction benefits of AAS. Recent studies have explored the possibility ofremediating the low early-age strength using calcium salts or silicate-based activators with a high silicatemodulus. These methods, while showing promise, often suffer from delayed setting times, and inadequatecompressive strength development in the 5–10°C range. As a result, they have not yet achieved satisfactoryperformance at early ages under low-temperature conditions. To achieve better results, there is a need todelve deeper into the impact of low temperatures on the fundamental mechanisms of AAS hydration—specifically, the dissolution-precipitation process. A better understanding of this stage is essential fordeveloping targeted solutions to the observed low reactivity. This study aims to investigate the role oftemperature during the dissolution phase of AAS hydration, the precursor to the precipitation reaction anda key determinant of early-age strength. Dissolution experiments (employing NaOH as an alkali activator)were conducted at 5°C, 20°C, and 40°C using a high liquid-to-solid ratio (500) to suppress precipitationand isolate the dissolution behaviour. Two complementary techniques were used to monitor dissolutionkinetics: pore solution conductivity measurements (over a 20-hour period) and continuous ICP-OESanalysis (over 120 minutes). The latter allowed real-time quantification of key ionic species such as Si, Ca,and Al. These solution-phase observations were supported by solid residue analysis using Scanning ElectronMicroscopy (SEM), Thermogravimetric Analysis (TGA), and X-Ray Diffraction (XRD) to detect anysecondary reaction products and unreacted phases. The results clearly show that dissolution is significantlyhindered at 5°C, which likely limits subsequent hydration and strength development. However, this adverseeffect can be mitigated by increasing the fineness of slag. Tests on coarse slag, fine slag (d50 = 10 μm), andultra-fine slag (d50 = 5 μm) revealed that higher specific surface area accelerates dissolution, even undercold conditions. In contrast, coarse slag achieved effective dissolution at elevated temperatures. Thesefindings suggest that optimizing slag fineness presents a practical and less energy-intensive route toimproving AAS performance in cold environments, thus unlocking its full potential in lowering the CO₂emissions of the construction industry. Building on these findings, ongoing research will explore alternativeactivation strategies to further enhance early-age AAS reactivity at low temperatures
Spatial analysis and mapping of malaria endemic-prone areas using environmental risk factors and spatial multi criteria decision analysis in the Northern Zone of Plateau State, Nigeria
No full textInternational audienceBackground & objectives: Compressive mapping and in-depth analysis of malaria vulnerability risk foci are important tools for strategic planning, vector surveillance, implementing necessary interventions, and managing scarce resources to combat the daunting challenges of malaria infections in Nigeria. Methods: The study utilized environmental risk factors and spatial multi-criteria decision analysis techniques to analyze and map the spatial variations in malaria-endemic prone areas within the Northern Zone of Plateau State. Results: Analysis of the criteria’s weights of environmental risk factors and the stratification of the malaria risk vulnerability revealed that high-risk areas covered a total of 4017.25 Km 2 , while low-risk areas covered 1294.83Km 2 , having a close resemblance to the corresponding ground conditions. The results showed that a significant 60% of the study areas were characterized by high risk of malaria transmission, particularly in most settlements around the Jos North, Jos South and Barkin Ladi Local Government Areas. The malaria risk map’s predictive abilities demonstrated a high level of accuracy, as indicated by the area under the curve score of 0.989. Furthermore, the risk map demonstrates a high-performance rate in identifying malaria hotspots, with a sensitivity of 98%, a proficiency rate of 54%, and a statistical significance confidence level ranging from 90% to 99% for identifying malaria hotspots and coldspots. Interpretation & conclusion: The malaria risk analysis and mapping within the endemic prone areas of the Northern Zone of Plateau State not only equips policymakers with effective tools for identifying malaria foci but also offers a deeper comprehension of the appropriate intervention measures to be implemented
Impact of Green‐Synthesized Zinc Oxide Nanoparticles (ZnO NPs) on the Biochemical and Histological Profiles of Cyprinus carpio
No full textInternational audienceThis study investigated the impact of varying concentrations, including 0.5 mg L −1 ( T 1 ), 1 mg L −1 ( T 2 ), and 2 mg L −1 ( T 3 ) of zinc oxide nanoparticles (ZnO NPs) on hematological, biochemical, and histological indices of Cyprinus carpio . As the use of ZnO NPs grows, there are rising concerns about their potential environmental impacts, particularly on aquatic ecosystems. When released into water bodies, these NPs can be ingested by aquatic organisms, leading to bioaccumulation and potential toxicity. Therefore, understanding their effects on aquatic species, like C. carpio , is crucial. Significant alterations in the erythrocyte count, hemoglobin (Hb), and hematocrit (Ht) levels were found. Compared to the control group, the number of lymphocytes, EOSO, monocytes, and platelets in the Zn NPs‐exposed groups dramatically increased. The biochemical analysis found considerable changes in blood total protein, albumin, globulin, and glucose levels. Histological examinations of the gills, intestines, and kidneys were conducted to assess structural or pathological changes. Treated fish showed progressive architectural distortions like necrosis (N), hyperplasia (HP), hypertrophy (HT), fusion of gill lamella (FGL), and proliferation of mucocytes (PM) in gills. Distension of the intercellular space (DIS), increased rate of the mucous cell (IMC), villous atrophy (VA), HP, and dysplasia (DP) were found in the intestines of ZnO NPs treated C. carpio . Tubular dilatation, tubular necrosis, severe congestion, hematopoietic tissue degradation, constricted lumen, glomerulopathy, and bowmans capsule dilution in kidneys of ZnO NPs treated C. carpio were noted. The findings from this study shed light on the biochemical and histological effects of ZnO NPs on C. carpio , contributing to a better understanding of the potential risks associated with NP exposure in aquatic environments. The results highlight the need to regulate the use of these NPs as well as their disposal in order to reduce the potential impact that they could have on aquatic ecosystems and public health
Enhancing Biodiversity‐Function Relationships in Field Retting: Towards Key Microbial Indicators for Retting Control
No full textInternational audienceHemp field retting is a bioprocess that facilitates fibre extraction by degrading pectin and other matrix components surrounding fibre bundles. However, traditional methods rely on empirical practices, often resulting in inconsistent fibre quality. This study investigates the biodiversity–function relationship in the hemp retting ecosystem to identify microbial and enzymatic indicators for improved process control. Over six weeks of field retting, we monitored bacterial and fungal community dynamics using high‐throughput sequencing and assessed enzymatic activity profiles. Our results revealed a sequential enzymatic pattern: pectinases (e.g., polygalacturonase) dominated early stages, followed by hemicellulases (β‐xylosidase, β‐galactosidase), and later cellulases. These enzymatic shifts were reflected in the changes in microbial community composition, with pectinolytic bacteria (e.g., Proteobacteria ) dominating the initial phases and cellulolytic fungi (e.g., Ascomycota ) becoming more prevalent later. Our results identified specific microbial taxa correlated with optimal retting, suggesting their potential as bioindicators for monitoring retting. Specifically, key bacterial genera such as Pseudomonas and Sphingomonas , and fungal genera like Cladosporium , were associated with distinct enzymatic profiles. Our findings offer new insights into the microbial ecology of retting, providing both microbial and enzymatic indicators that could inform the development of monitoring strategies for process control, ultimately contributing to more consistent hemp fibre production
Structural Build-Up of Cement Pastes: A Comprehensive Overview and Key Research Directions
No full textInternational audienceThe advancement of modern concretes, such as printable concrete, fluid concrete with adapted rheology, and ultra-high-performance concrete, has increased the importance of understanding structural build-up in cement-based materials. This process, which describes the time-dependent evolution of rheological properties, is a key factor to ensure the stability of concrete by influencing segregation, bleeding, formwork pressure, numerical modeling, and multi-layer casting. As a result, the structural build-up of cementitious materials has become a significant area of research in recent years. The structural build-up of cement based-materials results from both a reversible part (thixotropic behavior), driven by colloidal interactions, and an irreversible part, caused by cement hydration and the formation of C-S-H bridges. Various experimental techniques have been developed to investigate these processes, with various factors affecting the thixotropic behavior and overall structural build-up of cement suspensions. This review provides a comprehensive analysis of the current understanding of structural build-up in cement pastes. It covers measurement methods and key influencing factors, including the water-to-binder ratio (w/b), admixtures, temperature, and supplementary cementitious materials (SCMs). By consolidating the existing knowledge and identifying research gaps, this review aims to contribute to the development of sustainable, high-performance cement-based materials suitable for modern construction techniques
Type V: A sex-linked crossed resistance to three Cydia pomonella granulovirus isolates, with different levels of dominance
No full textInternational audienceThe codling moth (Cydia pomonella), is known to be resistant to many (bio)insecticides, including the Cydia pomonella granulovirus (CpGV). Of the multiple isolates available on the European market, two are already known to have selected resistance: Type I to CpGV-M and type II or III to group E (CpGV-S or -R5). In 2019, a monitoring program revealed three wild populations of insects with reduced susceptibility to the three main used virus isolates (CpGV-M, -R5 and -V15). In this context, our aim was to characterise this new type of resistance, referred to as Type V, and to determine its inheritance pattern and degree of dominance, and to investigate whether and how it differs from previously described resistance mechanisms.We collected a population previously identified as multiresistant from which several lines were isolated and selected during 13 generations with either CpGV-M, -R5 or no virus. Bioassays clearly showed high levels of resistance to CpGV-M, -R5 and -V15, as well as cross-resistance between the three isolates. Individual crossing experiments showed different inheritance modes for resistance to CpGV-M and CpGV-R in type V. Resistance to CpGV-M appeared dominant Z-linked as in type I, while it was more likely recessive, but still Z-linked for resistance to CpGV-R. Altogether, Type V is a novel type of resistance that cannot be overcome by CpGV-V15, and marked by a distinct inheritance pattern. Further research is needed to understand the relationship between resistance to each isolate, and adapt the future pest management strategies