Search results for: Olivier Fiquet

Authors: Rabaa Tlili Yaakoubi, Hind Nakouri, Olivier Blanpain

Abstract:

The current tools for real time management of sewer systems are based on two software tools: the software of weather forecast and the software of hydraulic simulation. The use of the first ones is an important cause of imprecision and uncertainty, the use of the second requires temporal important steps of decision because of their need in times of calculation. This way of proceeding fact that the obtained results are generally different from those waited. The major idea of the CARDIO project is to change the basic paradigm by approaching the problem by the "automatic" face rather than by that "hydrology". The objective is to make possible the realization of a large number of simulations at very short times (a few seconds) allowing to take place weather forecasts by using directly the real time meditative pluviometric data. The aim is to reach a system where the decision-making is realized from reliable data and where the correction of the error is permanent. A first model of control laws was realized and tested with different return-period rainfalls. The gains obtained in rejecting volume vary from 40 to 100%. The development of a new algorithm was then used to optimize calculation time and thus to overcome the subsequent combinatorial problem in our first approach. Finally, this new algorithm was tested with 16- year-rainfall series. The obtained gains are 60% of total volume rejected to the natural environment and of 80 % in the number of discharges.

Keywords: RTC, paradigm, optimization, automation

Procedia PDF Downloads 284

Authors: Min Yu, Olivier T. Picot, Theo Graves Saunders, Ivo Dlouhy, Amit Mahajan, Michael J. Reece

Abstract:

Graphene was successfully introduced into a polymer-derived silicon oxycarbide (SiOC) matrix by phase transfer of graphene oxide (GO) from an aqueous (GO dispersed in water) to an organic phase (copolymer as SiOC precursor in diethyl ether). With GO concentrations increasing up to 2 vol%, graphene-containing flakes self-assembled into a lamellar structure in the matrix leading to composite with the anisotropic property. Spark plasma sintering (SPS) was applied to densify the composites with four different GO concentrations (0, 0.5, 1 and 2 vol%) up to ~2.3 g/cm3. The fracture toughness of SiOC-2 vol% GO composites was significantly increased by ~91% (from 0.70 to 1.34 MPa·m¹/²), at the expense of a decrease in the flexural strength (from 85MPa to 55MPa), compared to SiOC-0 vol% GO composites. Moreover, the electrical conductivity in the perpendicular direction (σ┴=3×10⁻¹ S/cm) in SiOC-2 vol% GO composite was two orders of magnitude higher than the parallel direction (σ║=4.7×10⁻³ S/cm) owing to the self-assembled lamellar structure of graphene in the SiOC matrix. The composites exhibited increased electrical conductivity (σ┴) from 8.4×10⁻³ to 3×10⁻¹ S/cm, with the increasing GO content from 0.5 to 2 vol%. The SiOC-2 vol% GO composites further showed the better electrochemical performance of oxygen reduction reaction (ORR) than pure graphene, exhibiting a similar onset potential (~0.75V vs. RHE) and more positive half-wave potential (~0.6V vs. RHE).

Keywords: composite, fracture toughness, flexural strength, electrical conductivity, electrochemical performance

Procedia PDF Downloads 166

Authors: Malo Pocheau-Lesteven, Olivier Le Maître

Abstract:

Engineering and optimisation of complex systems is often achieved through multi-disciplinary analysis of the system, where each subsystem is modeled and interacts with other subsystems to model the complete system. The coherence of the output of the different sub-systems is achieved through the use of compatibility constraints, which enforce the coupling between the different subsystems. Due to the complexity of some sub-systems and the computational cost of evaluating their respective models, it is often necessary to build surrogate models of these subsystems to allow repeated evaluation these subsystems at a relatively low computational cost. In this paper, gaussian processes are used, as their probabilistic nature is leveraged to evaluate the likelihood of satisfying the compatibility constraints. This paper presents infilling strategies to build accurate surrogate models of the subsystems in areas where they are likely to meet the compatibility constraint. It is shown that these infilling strategies can reduce the computational cost of building surrogate models for a given level of accuracy. An application of these methods to velocity prediction programs used in offshore racing naval architecture further demonstrates these method's applicability in a real engineering context. Also, some examples of the application of uncertainty quantification to field of naval architecture are presented.

Keywords: infilling strategy, gaussian process, multi disciplinary analysis, velocity prediction program

Procedia PDF Downloads 157

Authors: Mbambu K. Shaloom, Biba Kalengo, Pierre Echard, Olivier Gilson, Tshiswaka Ngalula, Léonard Kabeya Mukeba Yakasham

Abstract:

In this 21st century, while design and eco-construction continue to be governed by considerations of functionality, safety, comfort and initial investment cost. Today, the principles of sustainable development lead us to think over longer time frames, to take into account new issues and the operating costs of green energy. DR Congo (sub-Saharan Africa) still suffers from the unusability of certain bio-sourced materials (such as bamboo, branches, etc.) and the lack of energy, i.e. 9% of the population has access to electricity and 21% of access to water. Ecoconstruction involves the energy performance of buildings which carry out a dynamic thermal simulation, which targets the different assumptions and conventional parameters (weather, occupancy, materials, thermal comfort, green energies, etc.). The objective of this article is to remedy the thermal, economic and technical artisanal problems in an aqueous environment in the city of Kinshasa. In order to establish a behavioral model to mitigate environmental impacts on architectural modifications and low-cost eco-construction through the approach of innovation and design thinking.

Keywords: thermal comfort, bio-sourced material, eco-architecture, eco-construction, squatting, design thinking

Procedia PDF Downloads 87

Authors: Olivier Mesly

Abstract:

This research presents a conceptual framework termed “Consumer Financial Spinning” (CFS) to analyze consumer behavior in the financial/economic markets. This phenomenon occurs when consumers of high-stakes financial products accumulate unsustainable debt, leading them to detach from their initial financial hierarchy of needs, wealth-related goals, and preferences regarding their household portfolio of assets. The daring actions of these consumers, forming a dark financial triangle, are characterized by three behaviors: overconfidence, the use of rationed rationality, and deceitfulness. We show that we can incorporate CFS into the traditional CAPM and Markovitz’ portfolio optimization models to create a framework that explains such market phenomena as the global financial crisis, highlighting the antecedents and consequences of ill-conceived speculation. Because this is a conceptual paper, there is no methodology with respect to ground studies. However, we apply modeling principles derived from the data percolation methodology, which contains tenets explicating how to structure concepts. A simulation test of the proposed framework is conducted; it demonstrates the conditions under which the relationship between expected returns and risk may deviate from linearity. The analysis and conceptual findings are particularly relevant both theoretically and pragmatically as they shed light on the psychological conditions that drive intense speculation, which can lead to market turmoil. Armed with such understanding, regulators are better equipped to propose solutions before the economic problems become out of control.

Keywords: consumer financial spinning, rationality, deceitfulness, overconfidence, CAPM

Procedia PDF Downloads 48

Authors: Sandra Tapin-Lingua, Katia Ruel, Jean-Paul Joseleau, Daouia Messaoudi, Olivier Fahy, Michel Petit-Conil

Abstract:

The preservative efficacy of organic biocides is strongly related to their capacity of penetration and retention within wood tissues. The specific detection of the pyrethroid insecticide is currently obtained after extraction followed by chemical analysis by chromatography techniques. However visualizing the insecticide molecule within the wood structure requires specific probes together with microscopy techniques. Therefore, the aim of the present work was to apply a new methodology based on antibody-antigen recognition and electronic microscopy to visualize directly pyrethroids in the wood material. A polyclonal antibody directed against cypermethrin was developed and implement it on Pinus sylvestris wood samples coated with technical cypermethrin. The antibody was tested on impregnated wood and the specific recognition of the insecticide was visualized in transmission electron microscopy (TEM). The immunogold-TEM assay evidenced the capacity of the synthetic biocide to penetrate in the wood. The depth of penetration was measured on sections taken at increasing distances from the coated surface of the wood. Such results correlated with chemical analyzes carried out by GC-ECD after extraction. In addition, the immuno-TEM investigation allowed visualizing, for the first time at the ultrastructure scale of resolution, that cypermethrin was able to diffuse within the secondary wood cell walls.

Keywords: cypermethrin, insecticide, wood penetration, wood retention, immuno-transmission electron microscopy, polyclonal antibody

Procedia PDF Downloads 413

Authors: Mennatallah M. Hussein, Olivier de Weck

Abstract:

The advancement of space exploration demands a robust space launch services program capable of reliably propelling payloads into orbit. Despite rigorous testing and quality assurance, launch failures still occur, leading to significant financial losses and jeopardizing mission objectives. Traditional failure prediction methods often lack the sophistication to account for multi-mode failure scenarios, as well as the predictive capability in complex dynamic systems. Traditional approaches also rely on expert judgment, leading to variability in risk prioritization and mitigation strategies. Hence, there is a pressing need for robust approaches that enhance launch vehicle reliability from lift-off until it reaches its parking orbit through comprehensive simulation techniques. In this study, the developed model proposes a multi-mode launch vehicle simulation framework for predicting failure scenarios when incorporating new technologies, such as new propulsion systems or advanced staging separation mechanisms in the launch system. To this end, the model combined a 6-DOF system dynamics with comprehensive data analysis to simulate multiple failure modes impacting launch performance. The simulator utilizes high-fidelity physics-based simulations to capture the complex interactions between different subsystems and environmental conditions.

Keywords: launch vehicle, failure prediction, propulsion anomalies, rocket launch simulation, rocket dynamics

Procedia PDF Downloads 31

Authors: Philippe Dillien, Patrice Forget, Harald Engel, Olivier Cornu, Marc De Kock, Jean Cyr Yombi

Abstract:

Introduction: Hip fracture precedes commonly death in elderly people. Identification of high-risk patients may contribute to target patients in whom optimal management, resource allocation and trials efficiency is needed. The aim of this study is to construct a predictive score of mortality after hip fracture on the basis of the objective prognostic factors available: Neutrophil-to-lymphocyte ratio (NLR), age, and sex. C-Reactive Protein (CRP), is also considered as an alternative to the NLR. Patients and methods: After the IRB approval, we analyzed our prospective database including 286 consecutive patients with hip fracture. A score was constructed combining age (1 point per decade above 74 years), sex (1 point for males), and NLR at postoperative day+5 (1 point if >5). A receiver-operating curve (ROC) curve analysis was performed. Results: From the 286 patients included, 235 were analyzed (72 males and 163 females, 30.6%/69.4%), with a median age of 84 (range: 65 to 102) years, mean NLR values of 6.47+/-6.07. At one year, 82/280 patients died (29.3%). Graphical analysis and log-rank test confirm a highly statistically significant difference (P<0.001). Performance analysis shows an AUC of 0.72 [95%CI 0.65-0.79]. CRP shows no advantage on NLR. Conclusion: We have developed a score based on age, sex and the NLR to predict the risk of mortality at one year in elderly patients after surgery for a hip fracture. After external validation, it may be included in clinical practice as in clinical research to stratify the risk of postoperative mortality.

Keywords: neutrophil-to-lymphocyte ratio, hip fracture, postoperative mortality, medical and health sciences

Procedia PDF Downloads 413

Authors: Hafiza Javaria Ashraf, Xinghong Wang, Zhanghong Shi, Youming Hou

Abstract:

Insect’s innate immunity depends on a variety of defense responses for the recognition of invading pathogens. Pathogen recognition involves particular proteins known as pattern recognition receptors (PRRs). These PRRs interact with pathogen-associated molecular patterns (PAMPs) present on the surface of pathogens to distinguish between self and non-self. C-type lectins (CTLs) belong to a superfamily of PPRs which involved in insect immunity and defense mechanism. Rhynchophorus ferrugineus Olivier is a devastating pest of Palm cultivations in China. Although studies on R. ferrugineus immune mechanism and host defense have conducted, however, the role of CTL in immune responses of R. ferrugineus remains elusive. Here, we report RfCTL, which is a secreted protein containing a single-CRD domain. The open reading frame (ORF) of CTL is 226 bp, which encodes a putative protein of 168 amino acids. Transcript expression analysis revealed that RfCTL highly expressed in immune-related tissues, i.e., hemolymph and fat body. The abundance of RfCTL in the gut and fat body dramatically increased upon Staphylococcus aureus and Escherichia coli bacterial challenges, suggesting a role in defense against gram-positive and gram-negative bacterial infection. Taken together, we inferred that RfCTL might be involved in the immune defense of R. ferrugineus and established a solid foundation for future studies on R. ferrugineus CTL domain proteins for better understanding of insect immunity.

Keywords: biological invasion, c-type lectin, insect immunity, Rhynchophorus ferrugineus Oliver

Procedia PDF Downloads 157

Authors: Olivier Chaigneau, Damianos Oikonomidis, Marie-Cecile Delmas

Abstract:

GAMBAS (Galileo Advanced features for the Maritime domain: Breakthrough Applications for Safety and security) is a project funded by the European Space Program Agency (EUSPA) aiming at identifying the search-and-rescue and ship security alert system needs for maritime users (including operators and fishing stakeholders) and developing operational concepts to answer these needs. The general objective of the GAMBAS project is to support the deployment of Galileo exclusive features in the maritime domain in order to improve safety and security at sea, detection of illegal activities and associated surveillance means, resilience to natural and human-induced emergency situations, and develop, integrate, demonstrate, standardize and disseminate these new associated capabilities. The project aims to demonstrate: improvement of the SAR (Search And Rescue) and SSAS (Ship Security Alert System) detection and response to maritime distress through the integration of new features into the beacon for SSAS in terms of cost optimization, user-friendly aspects, integration of Galileo and OS NMA (Open Service Navigation Message Authentication) reception for improved authenticated localization performance and reliability, and at sea triggering capabilities, optimization of the responsiveness of RCCs (Rescue Co-ordination Centre) towards the distress situations affecting vessels, the adaptation of the MCCs (Mission Control Center) and MEOLUT (Medium Earth Orbit Local User Terminal) to the data distribution of SSAS alerts.

Keywords: Galileo new advanced features, maritime, safety, security

Procedia PDF Downloads 93

Authors: Olivier Delage, Hassan Bencherif, Alain Bourdier

Abstract:

Signal decomposition approaches represent an important step in time series analysis, providing useful knowledge and insight into the data and underlying dynamics characteristics while also facilitating tasks such as noise removal and feature extraction. As most of observational time series are nonlinear and nonstationary, resulting of several physical processes interaction at different time scales, experimental time series have fluctuations at all time scales and requires the development of specific signal decomposition techniques. Most commonly used techniques are data driven, enabling to obtain well-behaved signal components without making any prior-assumptions on input data. Among the most popular time series decomposition techniques, most cited in the literature, are the empirical mode decomposition and its variants, the empirical wavelet transform and singular spectrum analysis. With increasing popularity and utility of these methods in wide ranging applications, it is imperative to gain a good understanding and insight into the operation of these algorithms. In this work, we describe all of the techniques mentioned above as well as their ability to denoise signals, to capture trends, to identify components corresponding to the physical processes involved in the evolution of the observed system and deduce the dimensionality of the underlying dynamics. Results obtained with all of these methods on experimental total ozone columns and rainfall time series will be discussed and compared

Keywords: denoising, empirical mode decomposition, singular spectrum analysis, time series, underlying dynamics, wavelet analysis

Procedia PDF Downloads 118

Authors: Renata Checiches, Thierry Coche, Nicolas F. Delahaye, Albert Linder, Fernando Ulloa Montoya, Olivier Gruselle, Karen Langfeld, An de Creus, Bart Spiessens, Vincent G. Brichard, Jamila Louahed, Frédéric F. Lehmann

Abstract:

Background: The RNA-expression levels of cancer-testis antigens MAGE A3 and PRAME were determined in resected tissue from patients with primary non-small-cell lung cancer (NSCLC) and related to clinical outcome. EGFR, KRAS and BRAF mutation status was determined in a subset to investigate associations with MAGE A3 and PRAME expression. Methods: We conducted a single-centre, uncontrolled, retrospective study of 1260 tissue-bank samples from stage IA-III resected NSCLC. The prognostic value of antigen expression (qRT-PCR) was determined by hazard-ratio and Kaplan-Meier curves. Results: Thirty-seven percent (314/844) of tumours expressed MAGE-A3, 66% (723/1092) expressed PRAME and 31% (239/839) expressed both. Respective frequencies in squamous-cell tumours and adenocarcinomas were 43%/30% for MAGE A3 and 80%/44% for PRAME. No correlation with stage, tumour size or patient age was found. Overall, no prognostic value was identified for either antigen. A trend to poorer overall survival was associated with MAGE-A3 in stage IIIB and with PRAME in stage IB. EGFR and KRAS mutations were found in 10.1% (28/311) and 33.8% (97/311) of tumours, respectively. EGFR (but not KRAS) mutation status was negatively associated with PRAME expression. Conclusion: No clear prognostic value for either PRAME or MAGE A3 was observed in the overall population, although some observed trends may warrant further investigation.

Keywords: MAGE A3, PRAME, cancer-testis gene, NSCLC, survival, EGFR

Procedia PDF Downloads 382

Authors: Dicko Ali Hamadi, Tong-Yette Nicolas, Gilles Benjamin, Faure Francois, Palombi Olivier

Abstract:

A novel hybrid model of the lumbar spine, allowing fast static and dynamic simulations of the disc pressure and the spine mobility, is introduced in this work. Our contribution is to combine rigid bodies, deformable finite elements, articular constraints, and springs into a unique model of the spine. Each vertebra is represented by a rigid body controlling a surface mesh to model contacts on the facet joints and the spinous process. The discs are modeled using a heterogeneous tetrahedral finite element model. The facet joints are represented as elastic joints with six degrees of freedom, while the ligaments are modeled using non-linear one-dimensional elastic elements. The challenge we tackle is to make these different models efficiently interact while respecting the principles of Anatomy and Mechanics. The mobility, the intradiscal pressure, the facet joint force and the instantaneous center of rotation of the lumbar spine are validated against the experimental and theoretical results of the literature on flexion, extension, lateral bending as well as axial rotation. Our hybrid model greatly simplifies the modeling task and dramatically accelerates the simulation of pressure within the discs, as well as the evaluation of the range of motion and the instantaneous centers of rotation, without penalizing precision. These results suggest that for some types of biomechanical simulations, simplified models allow far easier modeling and faster simulations compared to usual full-FEM approaches without any loss of accuracy.

Keywords: hybrid, modeling, fast simulation, lumbar spine

Procedia PDF Downloads 306

Authors: Marek Pawlikowski, Krzysztof Jankowski, Konstanty Skalski, Anna Makuch

Abstract:

Nanoindentation or depth-sensing indentation (DSI) technique has proven to be very useful to measure mechanical properties of various tissues at a micro-scale. Bone tissue, both trabecular and cortical one, is one of the most commonly tested tissues by means of DSI. Most often such tests on bone samples are carried out to compare the mechanical properties of lamellar and interlamellar bone, osteonal bone as well as compact and cancellous bone. In the paper, a relation between stress and strain for human trabecular bone is presented. The relation is based on the results of nanoindentation tests. The formulation of a constitutive model for human trabecular bone is based on nanoindentation tests. In the study, the approach proposed by Olivier-Pharr is adapted. The tests were carried out on samples of trabecular tissue extracted from human femoral heads. The heads were harvested during surgeries of artificial hip joint implantation. Before samples preparation, the heads were kept in 95% alcohol in temperature 4 Celsius degrees. The cubic samples cut out of the heads were stored in the same conditions. The dimensions of the specimens were 25 mm x 25 mm x 20 mm. The number of 20 samples have been tested. The age range of donors was between 56 and 83 years old. The tests were conducted with the indenter spherical tip of the diameter 0.200 mm. The maximum load was P = 500 mN and the loading rate 500 mN/min. The data obtained from the DSI tests allows one only to determine bone behoviour in terms of nanoindentation force vs. nanoindentation depth. However, it is more interesting and useful to know the characteristics of trabecular bone in the stress-strain domain. This allows one to simulate trabecular bone behaviour in a more realistic way. The stress-strain curves obtained in the study show relation between the age and the mechanical behaviour of trabecular bone. It was also observed that the bone matrix of trabecular tissue indicates an ability of energy absorption.

Keywords: constitutive model, mechanical behaviour, nanoindentation, trabecular bone

Procedia PDF Downloads 221

Authors: Victor Prevost, Solene Landerneau, Michel Duhamel, Joel Sternheimer, Olivier Gallet, Pedro Ferrandiz, Marwa Mokni

Abstract:

The search for homologous proteins is one of the ongoing challenges in biology and bioinformatics. Traditionally, a pair of proteins is thought to be homologous when they originate from the same ancestral protein. In such a case, their sequences share similarities, and advanced scientific research effort is spent to investigate this question. On this basis, we propose the Protein-Wave Alignment Tool (”P-WAT”) developed within the framework of the France Relance 2030 plan. Our work takes into consideration the mass-related wave aspect of protein biosynthesis, by associating specific frequencies to each amino acid according to its mass. Amino acids are then regrouped within their mass category. This way, our algorithm produces specific alignments in addition to those obtained with a common amino acid coding system. For this purpose, we develop the ”P-WAT” original algorithm, able to address large protein databases, with different attributes such as species, protein names, etc. that allow us to align user’s requests with a set of specific protein sequences. The primary intent of this algorithm is to achieve efficient alignments, in this specific conceptual frame, by minimizing execution costs and information loss. Our algorithm identifies sequence similarities by searching for matches of sub-sequences of different sizes, referred to as primers. Our algorithm relies on Boolean operations upon a dot plot matrix to identify primer amino acids common to both proteins which are likely to be part of a significant alignment of peptides. From those primers, dynamic programming-like traceback operations generate alignments and alignment scores based on an adjusted PAM250 matrix.

Keywords: protein, alignment, homologous, Genodic

Procedia PDF Downloads 113

Authors: Luleka Dlamini, Olivier Crespo, Jos van Dam

Abstract:

Accurately estimating crop growth and yield is pivotal for timely sustainable agricultural management and ensuring food security. Crop models and remote sensing can complement each other and form a robust analysis tool to improve crop growth and yield estimations when combined. This study thus aims to systematically evaluate how research that exclusively focuses on assimilating RS data into crop models varies among countries, crops, data assimilation methods, and farming conditions. A strict search string was applied in the Scopus and Web of Science databases, and 497 potential publications were obtained. After screening for relevance with predefined inclusion/exclusion criteria, 123 publications were considered in the final review. Results indicate that over 81% of the studies were conducted in countries associated with high socio-economic and technological advancement, mainly China, the United States of America, France, Germany, and Italy. Many of these studies integrated MODIS or Landsat data into WOFOST to improve crop growth and yield estimation of staple crops at the field and regional scales. Most studies use recalibration or updating methods alongside various algorithms to assimilate remotely sensed leaf area index into crop models. However, these methods cannot account for the uncertainties in remote sensing observations and the crop model itself. l. Over 85% of the studies were based on commercial and irrigated farming systems. Despite a great global interest in data assimilation into crop models, limited research has been conducted in resource- and data-limited regions like Africa. We foresee a great potential for such application in those conditions. Hence facilitating and expanding the use of such an approach, from which developing farming communities could benefit.

Keywords: crop models, remote sensing, data assimilation, crop yield estimation

Procedia PDF Downloads 131

Authors: Luleka Dlamini, Olivier Crespo, Jos van Dam

Abstract:

Accurately estimating crop growth and yield is pivotal for timely sustainable agricultural management and ensuring food security. Crop models and remote sensing can complement each other and form a robust analysis tool to improve crop growth and yield estimations when combined. This study thus aims to systematically evaluate how research that exclusively focuses on assimilating RS data into crop models varies among countries, crops, data assimilation methods, and farming conditions. A strict search string was applied in the Scopus and Web of Science databases, and 497 potential publications were obtained. After screening for relevance with predefined inclusion/exclusion criteria, 123 publications were considered in the final review. Results indicate that over 81% of the studies were conducted in countries associated with high socio-economic and technological advancement, mainly China, the United States of America, France, Germany, and Italy. Many of these studies integrated MODIS or Landsat data into WOFOST to improve crop growth and yield estimation of staple crops at the field and regional scales. Most studies use recalibration or updating methods alongside various algorithms to assimilate remotely sensed leaf area index into crop models. However, these methods cannot account for the uncertainties in remote sensing observations and the crop model itself. l. Over 85% of the studies were based on commercial and irrigated farming systems. Despite a great global interest in data assimilation into crop models, limited research has been conducted in resource- and data-limited regions like Africa. We foresee a great potential for such application in those conditions. Hence facilitating and expanding the use of such an approach, from which developing farming communities could benefit.

Keywords: crop models, remote sensing, data assimilation, crop yield estimation

Procedia PDF Downloads 82

Authors: Fils Olivier Kamanzi

Abstract:

This research Paper shows that materials CFRP were used to rehabilitate 9 Beams and retrofitting of 9 Beams with size (125x250x2300) mm each for M50 grade of concrete with 20% of Volume of Cement replaced by GGBS as a mineral Admixture. Superplasticizer (ForscoConplast SP430) used to reduce the water-cement ratio and maintaining good workability of fresh concrete (Slump test 57mm). Concrete Mix ratio 1:1.56:2.66 with a water-cement ratio of 0.31(ACI codebooks). A sample of 6cubes sized (150X150X150) mm, 6cylinders sized (150ФX300H) mm and 6Prisms sized (100X100X500) mm were cast, cured, and tested for 7,14&28days by compressive, tensile and flexure test; finally, mix design reaches the compressive strength of 59.84N/mm2. 21 Beams were cast and cured for up to 28 days, 3Beams were tested by a two-point loading machine as Control beams. 9 Beams were distressed in flexure by adopting failure up to final Yielding point under two-point loading conditions by taking 90% off Ultimate load. Three sets, each composed of three distressed beams, were rehabilitated by using CFRP sheets, one, two & three layers, respectively, and after being retested up to failure mode. Another three sets were freshly retrofitted also by using CFRP sheets one, two & three layers, respectively, and being tested by a two-point load method of compression strength testing machine. The aim of this study is to determine the flexural Strength & behaviors of repaired and retrofitted Beams by CFRP sheets for gaining good strength and considering economic aspects. The results show that rehabilitated beams increase its strength 47 %, 78 % & 89 %, respectively, to thickness of CFRP sheets and 41%, 51 %& 68 %, respectively too, for retrofitted Beams. The conclusion is that three layers of CFRP sheets are the best applicable in repairing and retrofitting the bonded beams method.

Keywords: retrofitting, rehabilitation, cfrp, rcc beam, flexural strength and behaviors, ggbs, and epoxy resin

Procedia PDF Downloads 108

Authors: Keltoum Bouherine, Olivier Leroy

Abstract:

The present work is dedicated to study a three–dimensional (3D) self-consistent fluid simulation of microwave discharges of argon plasma in PECVD reactor. The model solves the Maxwell’s equations, continuity equations for charged species and the electron energy balance equation, coupled with Poisson’s equation, and Navier-Stokes equations by finite element method, using COMSOL Multiphysics software. In this study, the simulations yield the profiles of plasma components as well as the charge densities and electron temperature, the electric field, the gas velocity, and gas temperature. The results show that the microwave plasma reactor is outside of local thermodynamic equilibrium.The present work is dedicated to study a three–dimensional (3D) self-consistent fluid simulation of microwave discharges of argon plasma in PECVD reactor. The model solves the Maxwell’s equations, continuity equations for charged species and the electron energy balance equation, coupled with Poisson’s equation, and Navier-Stokes equations by finite element method, using COMSOL Multiphysics software. In this study, the simulations yield the profiles of plasma components as well as the charge densities and electron temperature, the electric field, the gas velocity, and gas temperature. The results show that the microwave plasma reactor is outside of local thermodynamic equilibrium.

Keywords: electron density, electric field, microwave plasma reactor, gas velocity, non-equilibrium plasma

Procedia PDF Downloads 331

Authors: Donia Fredj, Marie Parmentier, Florence Archet, Olivier Margeat, Sadok Ben Dkhil, Jorg Ackerman

Abstract:

Transparent conductive electrodes (TCEs) or transparent electrodes (TEs) are a crucial part of many electronic and optoelectronic devices such as touch panels, liquid crystal displays (LCDs), organic light-emitting diodes (OLEDs), solar cells, and transparent heaters. The indium tin oxide (ITO) electrode is the most widely utilized transparent electrode due to its excellent optoelectrical properties. However, the drawbacks of ITO, such as the high cost of this material, scarcity of indium, and the fragile nature, limit the application in large-scale flexible electronic devices. Importantly, flexibility is becoming more and more attractive since flexible electrodes have the potential to open new applications which require transparent electrodes to be flexible, cheap, and compatible with large-scale manufacturing methods. So far, several materials as alternatives to ITO have been developed, including metal nanowires, conjugated polymers, carbon nanotubes, graphene, etc., which have been extensively investigated for use as flexible and low-cost electrodes. Among them, silver nanowires (AgNW) are one of the promising alternatives to ITO thanks to their excellent properties, high electrical conductivity as well as desirable light transmittance. In recent years, inkjet printing became a promising technique for large-scale printed flexible and stretchable electronics. However, inkjet printing of AgNWs still presents many challenges. In this study, a synthesis of stable AgNW that could compete with ITO was developed. This material was printed by inkjet technology directly on a flexible substrate. Additionally, we analyzed the surface microstructure, optical and electrical properties of the printed AgNW layers. Our further research focused on the study of all inkjet-printed organic modules with high efficiency.

Keywords: transparent electrodes, silver nanowires, inkjet printing, formulation of stable inks

Procedia PDF Downloads 222

Authors: Gebreslassie Gebru, Gurja Belay, Minister Birhanie, Mulalem Zenebe, Tadelle Dessie, Adriana Vallejo-Trujillo, Olivier Hanotte

Abstract:

Livestock must adapt to changing environmental conditions, which can result in either phenotypic plasticity or irreversible phenotypic change. In this study, we combine Ecological Niche Modelling (ENM) and Phenotypic Distribution Modelling (PDM) to provide a comprehensive framework for understanding the ecological and phenotypic characteristics of indigenous chicken (Gallus gallus domesticus) ecotypes. This approach helped us to classify these ecotypes, differentiate their phenotypic traits, and identify associations between environmental variables and adaptive traits. We measured 297 adult indigenous chickens from various agro-ecologies, including 208 females and 89 males. A subset of the 22 measured traits was selected using stepwise selection, resulting in seven traits for each sex. Using ENM, we identified four agro-ecologies potentially harbouring distinct phenotypes of indigenous Tigray chickens. However, PDM classified these chickens into three phenotypical ecotypes. Chickens grouped in ecotype-1 and ecotype-3 exhibited superior adaptive traits compared to those in ecotype-2, with significant variance observed. This high variance suggests a broader range of trait expression within these ecotypes, indicating greater adaptation capacity and potentially more diverse genetic characteristics. Several environmental variables, such as soil clay content, forest cover, and mean temperature of the wettest quarter, were strongly associated with most phenotypic traits. This suggests that these environmental factors play a role in shaping the observed phenotypic variations. By integrating ENM and PDM, this study enhances our understanding of indigenous chickens' ecological and phenotypic diversity. It also provides valuable insights into their conservation and management in response to environmental changes.

Keywords: adaptive traits, agro-ecology, appendage, climate, environment, imagej, morphology, phenotypic variation

Procedia PDF Downloads 33

Authors: Marie Fouet, Olivier Maire, Cécile Masse, Hugues Blanchet, Salomé Coignard, Nicolas Lavesque, Guillaume Bernard

Abstract:

Exacerbated by global change, extreme climatic events such as atmospheric and marine heat waves may interact with the spread of non-indigenous species and their associated impacts on marine ecosystems. Since the 1970’s, the introduction of non-indigenous species due to oyster exchanges has been numerous. Among them, the Asian date mussel Arcuatula senhousia has colonized a large number of ecosystems worldwide (e.g., California, New Zealand, Italy). In these places, A.senhousia led to important habitat modifications in the benthic compartment through physical, biological, and biogeochemical effects associated with the development of dense mussel populations. In Arcachon Bay (France), a coastal lagoon of the French Atlantic and hotspot of oyster farming, abundances of A. senhousia recently increased, following a lag time of ca. 20 years since the first record of the species in 2002. Here, we addressed the potential effects of the interaction between A. senhousia invasion and heatwave intensity on ecosystem functioning within an intertidal mudflat. More precisely, two realistic intensities (“High” and “Severe”) of combined marine and atmospheric heatwaves have been simulated in an experimental tidal mesocosm system onto which naturally varying densities of A. senhousia and associated benthic communities were exposed in sediment cores collected in situ. Following a six-day exposure, community-scale responses were assessed by measuring benthic metabolism (oxygen and nutrient fluxes) in each core. Results show that besides significantly enhanced benthic metabolism with increasing heatwave intensity, mussel density clearly mediated the magnitude of the community-scale response, thereby highlighting the importance of understanding the interactive effects of environmental stressors co-occurring with non-indigenous species and their dependencies for a better assessment of their impacts.

Keywords: arcuatula senhousia, benthic habitat, ecosystem functioning, heatwaves, metabolism

Procedia PDF Downloads 68

Authors: Muhammad Mamoon-Ur-Rashid, Gul Rehman

Abstract:

Entomopathogenic fungi are considered effective bio-control agents for the management of a range of insect pests including red palm weevil. The research studies were conducted under laboratory and field conditions against 5th and 6th instars larvae and adults of [Rhynchophorus ferrugineus (Olivier)] at the faculty of Agriculture, Gomal University Dera Ismail Khan (KPK) Pakistan. The 5th instar larvae were used under field conditions whereas, the 6th instar larvae and newly emerged adults were used under lab conditions. Conidial suspensions were used at five different concentrations of 1×10⁴, 1×10⁵, 1×10⁶, 1×10⁷ and 1×10⁸, conidia per ml. The data were recorded on the mortality, total larval duration, weight of larvae, pre-pupal and pupal durations, percent pupal formation, pupal weight, percent adult emergence, and adult longevity (♂ and ♀) of red palm weevil. The B. bassiana had varying degrees of pathogenicity against different developmental stages of red palm weevil. The maximum larval duration (113.40 days) was noted when 5th instar larvae were treated with the maximum concentration (1 × 10⁸) of B. bassiana, whereas; the minimum total larval duration of 87.20 days was recorded on the lowest concentration (1 × 10⁴) of B. bassiana. The maximum pre-pual and pupal durations were noted at the maximum concentration. The maximum life span of adult male and females were noted at the lowest concentration, whereas; the minimum values were noted at the maximum concentration. The earliest mortality of red palm weevil was observed 1-day after treatment at higher concentrations of 1 × 10⁷ and 1 × 10⁸, whereas; it was recorded 3 and 4 days after treatment at lower concentrations of 1 × 10⁵ and 1 × 10⁴. At 10 days after treatment, the entomopathogenic fungus caused > 80% cumulative mortality of 5th and 6th instar larvae and adult weevils at the maximum concentrations which were more than double than those recorded at the lowest concentration. Overall, the 5th instar larvae of red palm weevils were most susceptible to the fungus compared to the 6th instar larvae and adult weevils. Based on current findings, it is suggested that entomopathogenic fungi could be used for the safer management of red palm weevil.

Keywords: entomopathogenic nematodes, mortality, red palm weevil, sub-lethal effects

Procedia PDF Downloads 92

Authors: Hoai Nam Huynh, Edouard Rivière-Lorphèvre, Olivier Verlinden

Abstract:

Manufacturing technologies are becoming continuously more diversified over the years. The increasing use of robots for various applications such as assembling, painting, welding has also affected the field of machining. Machining robots can deal with larger workspaces than conventional machine-tools at a lower cost and thus represent a very promising alternative for machining applications. Furthermore, their inherent structure ensures them a great flexibility of motion to reach any location on the workpiece with the desired orientation. Nevertheless, machining robots suffer from a lack of stiffness at their joints restricting their use to applications involving low cutting forces especially finishing operations. Vibratory instabilities may also happen while machining and deteriorate the precision leading to scrap parts. Some researchers are therefore concerned with the identification of optimal parameters in robotic machining. This paper continues the development of a virtual robotic machining simulator in order to find optimized cutting parameters in terms of depth of cut or feed per tooth for example. The simulation environment combines an in-house milling routine (DyStaMill) achieving the computation of cutting forces and material removal with an in-house multibody library (EasyDyn) which is used to build a dynamic model of a 3-DOF planar robot with flexible links. The position of the robot end-effector submitted to milling forces is controlled through an inverse kinematics scheme while controlling the position of its joints separately. Each joint is actuated through a servomotor for which the transfer function has been computed in order to tune the corresponding controller. The output results feature the evolution of the cutting forces when the robot structure is deformable or not and the tracking errors of the end-effector. Illustrations of the resulting machined surfaces are also presented. The consideration of the links flexibility has highlighted an increase of the cutting forces magnitude. This proof of concept will aim to enrich the database of results in robotic machining for potential improvements in production.

Keywords: control, milling, multibody, robotic, simulation

Procedia PDF Downloads 249

Authors: Paolo Ragazzi, Olivier Peillon, Paul Fauris, Mathias Simon, Raul Navarro, Juan Carlos Martin, Oriol Casasayas, Laura Pacheco, Albert Perez-Bellmunt

Abstract:

Introduction: The use of stretching techniques in the sports world is frequent and widely used for its many effects. One of the main benefits is the gain in flexibility, range of motion and facilitation of the sporting performance. Recently the use of Roller-Foam (RF) has spread in sports practice both at elite and recreational level for its benefits being similar to those observed in stretching. The objective of the following study is to compare the results of the Roller-Foam with the proprioceptive neuromuscular facilitation stretching (PNF) (one of the stretchings with more evidence) on the hamstring muscles. Study design: The design of the study is a single-blind, randomized controlled trial and the participants are 40 healthy volunteers. Intervention: The subjects are distributed randomly in one of the following groups; stretching (PNF) intervention group: 4 repetitions of PNF stretching (5seconds of contraction, 5 second of relaxation, 20 second stretch), Roller-Foam intervention group: 2 minutes of Roller-Foam was realized on the hamstring muscles. Main outcome measures: hamstring muscles flexibility was assessed at the beginning, during (30’’ of intervention) and the end of the session by using the Modified Sit and Reach test (MSR). Results: The baseline results data given in both groups are comparable to each other. The PNF group obtained an increase in flexibility of 3,1 cm at 30 seconds (first series) and of 5,1 cm at 2 minutes (the last of all series). The RF group obtained a 0,6 cm difference at 30 seconds and 2,4 cm after 2 minutes of application of roller foam. The results were statistically significant when comparing intragroups but not intergroups. Conclusions: Despite the fact that the use of roller foam is spreading in the sports and rehabilitation field, the results of the present study suggest that the gain of flexibility on the hamstrings is greater if PNF type stretches are used instead of RF. These results may be due to the fact that the use of roller foam intervened more in the fascial tissue, while the stretches intervene more in the myotendinous unit. Future studies are needed, increasing the sample number and diversifying the types of stretching.

Keywords: hamstring muscle, stretching, neuromuscular facilitation stretching, roller foam

Procedia PDF Downloads 187

Authors: Raimoana Frogier, Luc Girard, Pierre Bauduin, Diane Rebiscoul, Olivier Diat

Abstract:

Nano-ions (NIs) are ionic species or clusters of nanometric size. Their low charge density and the delocalization of their charges give special properties to some of NIs belonging to chemical classes of polyoxometalates (POMs) or boron clusters. They have the particularity of interacting non-covalently with neutral hydrated surface or interfaces such as assemblies of surface-active molecules (micelles, vesicles, lyotropic liquid crystals), foam bubbles or emulsion droplets. This makes possible to classify those NIs in the Hofmeister series as superchaotropic ions. The mechanism of adsorption is complex, linked to the simultaneous dehydration of the ion and the molecule or supramolecular assembly with which it can interact, all with an enthalpic gain on the free energy of the system. This interaction process is reversible and is sufficiently pronounced to induce changes in molecular and supramolecular shape or conformation, phase transitions in the liquid phase, all at sub-millimolar ionic concentrations. This new property of some NIs opens up new possibilities for applications in fields as varied as biochemistry for solubilization, recovery of metals of interest by foams in the form of NIs... In order to better understand the physico-chemical mechanisms at the origin of this interaction, we use silicon wafers functionalized by non-ionic oligomers (polyethylene glycol chains or PEG) to study in situ by X-ray reflectivity this interaction of NIs with the grafted chains. This study carried out at ESRF (European Synchrotron Radiation Facility) and has shown that the adsorption of the NIs, such as POMs, has a very fast kinetics. Moreover the distribution of the NIs in the grafted PEG chain layer was quantify. These results are very encouraging and confirm what has been observed on soft interfaces such as micelles or foams. The possibility to play on the density, length and chemical nature of the grafted chains makes this system an ideal tool to provide kinetic and thermodynamic information to decipher the complex mechanisms at the origin of this adsorption.

Keywords: adsorption, nano-ions, solid-liquid interface, superchaotropicity

Procedia PDF Downloads 67

Authors: Baptiste Vallet-Simond, Léopold V. B. Diop, Olivier Isnard

Abstract:

The antiferromagnetic itinerant-electron compound LaFe₁₂B₆ occupies a special place among rare-earth iron-rich intermetallic; it presents exotic magnetic and physical properties. The unusual amplitude-modulated spin configuration defined by a propagation vector k = (¼, ¼, ¼), remarkably weak Fe magnetic moment (0.43 μB) in the antiferromagnetic ground state, especially low magnetic ordering temperature TN = 36 K for an Fe-rich phase, a multicritical point in the complex magnetic phase diagram, both normal and inverse magnetocaloric effects, and huge hydrostatic pressure effects can be highlighted as the most relevant. Both antiferromagnetic (AFM) and paramagnetic (PM) states can be transformed into the ferromagnetic (FM) state via a field-induced first-order metamagnetic transition. Of particular interest is the low-temperature magnetization process. This process is discontinuous and evolves unexpected huge metamagnetic transitions consisting of a succession of steep magnetization jumps separated by plateaus, giving rise to an unusual avalanche-like behavior. The metamagnetic transition is accompanied by giant magnetoresistance and large magnetostriction. In the present work, we report on the intrinsic magnetic properties of the La₁₋ₓPrₓFe₁₂B₆ series of compounds exhibiting sharp metamagnetic transitions. The study of the structural, magnetic, magneto-transport, and magnetostrictive properties of the La₁₋ₓPrₓFe₁₂B₆ system was performed by combining a wide variety of measurement techniques. Magnetic measurements were performed up to µ0H = 10 T. It was found that the proportion of Pr had a strong influence on the magnetic properties of this series of compounds. At x=0.05, the ground state at 2K is that of an antiferromagnet, but the critical transition field Hc has been lowered from Hc = 6T at x = 0 to Hc = 2.5 Tat x=0.05. And starting from x=0.10, the ground state of this series of compounds is a coexistence of AFM and FM parts. At x=0.30, the AFM order has completely vanished, and only the FM part is left. However, we still observe meta-magnetic transitions at higher temperatures (above 100 K for x=0.30) from the paramagnetic (P) state to a forced FM state. And, of course, such transitions are accompanied by strong magneto-caloric, magnetostrictive, and magnetoresistance effects. The Curie temperatures for the probed compositions going from x=0.05 to x=0.30 were spread over the temperature range of 40 K up to 100 K.

Keywords: metamagnetism, RMB intermetallic, magneto-transport effect, metamagnetic transitions

Procedia PDF Downloads 69

Authors: Mazyar Yosofi, Olivier Kerbrat, Pascal Mognol

Abstract:

Life cycle assessment of additive manufacturing processes has evolved significantly since these past years. A lot of existing studies mainly focused on energy consumption. Nowadays, new methodologies of life cycle inventory acquisition came through the literature and help manufacturers to take into account all the input and output flows during the manufacturing step of the life cycle of products. Indeed, the environmental analysis of the phenomena that occur during the manufacturing step of additive manufacturing processes is going to be well known. Now it becomes possible to count and measure accurately all the inventory data during the manufacturing step. Optimization of the environmental performances of processes can now be considered. Environmental performance improvement can be made by varying process parameters. However, a lot of these parameters (such as manufacturing speed, the power of the energy source, quantity of support materials) affect directly the mechanical properties, surface finish and the dimensional accuracy of a functional part. This study aims to improve the environmental performance of an additive manufacturing process without deterioration of the part quality. For that purpose, the authors have developed a generic method that has been applied on multiple parts made by additive manufacturing processes. First, a complete analysis of the process parameters is made in order to identify which parameters affect only the environmental performances of the process. Then, multiple parts are manufactured by varying the identified parameters. The aim of the second step is to find the optimum value of the parameters that decrease significantly the environmental impact of the process and keep the part quality as desired. Finally, a comparison between the part made by initials parameters and changed parameters is made. In this study, the major finding claims by authors is to reduce the environmental impact of an additive manufacturing process while respecting the three quality criterion of parts, mechanical properties, dimensional accuracy and surface roughness. Now that additive manufacturing processes can be seen as mature from a technical point of view, environmental improvement of these processes can be considered while respecting the part properties. The first part of this study presents the methodology applied to multiple academic parts. Then, the validity of the methodology is demonstrated on functional parts.

Keywords: additive manufacturing, environmental impact, environmental improvement, mechanical properties

Procedia PDF Downloads 288

Authors: Steeve Mercier, Joan Netten, Olivier Massé

Abstract:

The traditional lack of success of most Canadian students in the regular French program in attaining the ability to communicate spontaneously led to the conceptualization of a modified program. This program, called Intensive French, introduced and evaluated as an experiment in several school districts, formed the basis for the creation of a more effective approach for the development of skills in a second/foreign language and literacy: the Neurolinguistic Approach (NLA).The NLA expresses the major change in the understanding of how communication skills are developed: learning to communicate spontaneously in a second language depends on the reuse of structures in a variety of cognitive situations to express authentic messages rather than on knowledge of the way a language functions. Put differently, it prioritises the acquisition of implicit competence over the learning of grammatical knowledge. This is achieved by the adoption of a literacy-based approach and an increase in intensity of instruction.Besides having strong support empirically from numerous experiments, the NLA has sound theoretical foundation, as it conforms to research in neurolinguistics. The five pedagogical principles that define the approach will be explained, as well as the differences between the NLA and the paradigm on which most current resources and teaching strategies are based. It is now 25 years since the original research occurred. The use of the NLA, as it will be shown, has expanded widely. With some adaptations, it is used for other languages and in other milieus. In Canada, classes are offered in mandarin, Ukrainian, Spanish and Arabic, amongst others. It has also been used in several indigenous communities, such as to restore the use of Mohawk, Cri and Dene. Its use has expanded throughout the world, as in China, Japan, France, Germany, Belgium, Poland, Russia, as well as Mexico. The Intensive French program originally focussed on students in grades 5 or 6 (ages 10 -12); nowadays, the programs based on the approach include adults, particularly immigrants entering new countries. With the increasing interest in inclusion and cultural diversity, there is a demand for language learning amongst pre-school and primary children that can be successfully addressed by the NLA. Other current experiments target trilingual schools and work with Inuit communities of Nunavik in the province of Quebec.

Keywords: neuroeducation, neurolinguistic approach, literacy, second language acquisition, plurilingualism, foreign language teaching and learning

Procedia PDF Downloads 73

Authors: Philippe Judlin, Olivier Morel

Abstract:

Background: In France, the resident curriculum (RC) in Obstetrics and Gynecology (OBGYN) takes five years. In the course of the last 15 years, this RC has undergone major changes, characterized mainly by successive reductions of work hours. The program used to comprise long and frequent shifts, huge workload, poor supervision and erratic theoretical teaching. A decade ago, the French Ministry of Heath recommended a limitation of shift duration up to 24 hours and a minimum of 11 hours off duty between shifts. Last year, in order to comply with European Union directives, new recommendations have further limited residents’ work hours to 48 hours per week. Methods: Assessment of the residency program adjustments recently made to accommodate the recommendations while improving the training quality in resorting to new methods. Results: The challenge facing program directors was to provide an all-encompassing curriculum to OBGYN residents despite fewer work hours. Program has been dramatically redesigned, and several measures have been put in place: -The resident rotation system has been redesigned. Residents used to make 6-month rotations between 10-12 Departments of OBGYN or Surgery. Fewer Departments, those providing the best teaching, have been kept in the new RC. -Extensive inhouse supervision has been implemented for all kinds of clinical activities. Effectual supervision of residents has proved to be an effective tool to improve the quality of training. -The tutorship system, with academic members individually overseeing residents during their curriculum, has been perfected. It allows a better follow-up of residents’ progresses during the 5-year program. -The set up of an extensive program of lectures encompassing all maters in Obstetrics & Gynecology. These mandatory lectures are available online in a dedicated website. Therefore, face-to-face lectures have been limited in order to fit in the 48-hour limit. -The use of simulation has been significantly increased in obstetrics, materno-fetal medicine and surgery (stressing especially laparoscopic training). -Residents’ feedback has been taken into account in the setup of the new RC. Conclusion: This extensive overhaul of the Obstetrics and Gynecology RC has been in place since last year only. Nevertheless, the new program seems to adequately take into account the new recommendations while providing a better and more consistent teaching to the OBGYN residents.

Keywords: education, laparoscopy, residency, simulation

Procedia PDF Downloads 186