De Laval Research Articles

Nanoparticles-induced heterogeneous condensation and geometry optimizations to enhance liquefaction efficiency and mitigate exergy loss in a novel hydrogen liquefaction two-phase expander

Hydrogen liquefaction methods primarily rely on various refrigeration cycles and nanoparticles are integrated into process to enhance the liquid hydrogen production yield by modifying material properties. Besides, the nanoparticles can induce the heterogeneous condensation in a novel hydrogen liquefaction transonic two-phase expander(TTPE). The TTPE is modeled as a De Laval nozzle for simplification and numerical technology is applied to improve the efficiency and minimize the exergy loss of hydrogen liquefaction by focusing on non-equilibrium condensation. For the first time, a mathematical model is established for a heterogeneous non-equilibrium condensing flow with hydrogen liquefaction incorporating the effect of nanoparticle. By introducing nanoparticles with boundary conditions set at a concentration of 10181/kg and a 10 nm radius, the efficiency of hydrogen liquefaction can be maximally enhanced by 4.29 %. Additional, by optimizing the geometrical structure of the de Laval nozzle, efficiency is improved by 2.93 % and 9.30 %, respectively, with further potential enhancements. Detailed analyses for TTPE are conducted of hydrogen liquefaction flow losses, thermal efficiency and total exergy loss under different flow conditions. Precise control of nanoparticle concentration and size, along with the regulation of intake compression and expansion state are necessary to enhance the feasibility of the liquefaction process. Finally, we discuss future research directions aimed at comprehensively enhancing the liquid hydrogen yield and reducing total energy consumption losses through effective and achievable strategies.

Continuous/smooth transonic solutions to the quasi-one-dimensional steady relativistic Euler equations

This paper establishes the existence and uniqueness of continuous/smooth Meyer type transonic solutions to the quasi-one-dimensional steady isentropic relativistic Euler equations. We use the high-order Taylor’s expansion of the velocity near the sonic point to overcome the difficulties of applying the implicit function theorem caused by the sonic degeneracy. It is verified that the flow in the De Laval nozzle accelerates from subsonic upstream and continuously/smoothly pass through the sonic surface at the throat and then becomes supersonic downstream. Moreover, the flow may have a zero or positive acceleration at the sonic surface, which depends on the geometric property of the nozzle at the throat.

CFD Analysis of De Laval Nozzle of a Hybrid Rocket Engine

: The study gives a general overview of the CFD-simulated gas flow via the nozzle of a De Laval rocket engine. In CFD software, the mesh is generated using the nozzle’s geometry. In this work, CFD methods are used to compare a number of factors with those derived from classical theory, such as pressure, velocity, temperature, and arear ratios. The results of computational modelling of CFD simulation are comparable to those found from theoretical calculations.

Supersonic jet noise and screech tone suppression using cross-wire

This experimental investigation is aimed at assessing how the introduction of a cross-wire at the exit of a CD nozzle influences the performance of a supersonic nozzle. The study focuses on cold air jets generated by De Laval nozzles equipped with cross-wires and baseline configurations, particularly at design Mach numbers of 1.5 and 1.75. The investigation involves collecting measurements from the noise field emitted by the cross-wire nozzle with a 2% obstruction at the exit. This passive control approach effectively reduces the occurrence of screech tones in both over-expanded and under-expanded conditions in the azimuthal plane at appropriate operating pressures. Various acoustic parameters, including sound pressure levels (SPL), Strouhal numbers, and the overall sound pressure level spectra (OASPL) are recorded. Schlieren imaging captures images of shock cell patterns, illustrating the impact of shock-associated noise. In comparison to a baseline nozzle, the results demonstrate that a CD nozzle equipped with a cross-wire proves to be a proficient screech tone suppressor, leading to an average reduction of up to 5 dB in OASPL in under-expanded and over-expanded scenarios.

Laser ionization scheme development for in-gas-jet spectroscopy studies of Th+

The in-gas laser ionization and spectroscopy (IGLIS) technique has been a cornerstone in the study of heavy elements. The addition of a convergent–divergent (de Laval) nozzle to perform laser ionization in a cold hypersonic gas jet greatly improves the achievable resolution. Recent efforts have focused on preparing the in-gas-jet method for the study of the low-lying 229Th isomer. Tailor-made recoil sources of 233U are installed inside a fast extraction gas cell to provide the (isomeric) thorium ions. A level search above the second ionization potential (IP) uncovered several auto-ionizing states, greatly improving the laser ionization efficiency of singly charged thorium ions.

Effect of zero penetration angle chevrons in supersonic jet noise and screech tone mitigation

Abstract An experimental study is conducted to determine the effect of chevrons with zero penetration angles at the CD nozzle exit on an emitted noise field. The implication of passive control is to reduce the blockage of the nozzle exit area with minimal engine thrust penalty. The cold air jets issued at design Mach numbers 1.5 and 1.75 from the De Laval nozzles of the circular section were investigated. This passive control eliminates screech tones at the over and ideally expanded conditions at 60° and 90° in the azimuth plane. The acoustic data measurements have also been observed for the chosen jet Mach numbers. The schlieren images reveal the shock cell pattern to eliminate the effect of shock-associated noise levels at supersonic jets. The results show that 10 chevrons with no penetration act as an effective eliminator of screech tone and noise suppression average ∆OASPL value up to 3 dB at Mach number 1.75.

CONVERGENT AND DIVERGENT ANGLES OF A SOLID-FUEL ROCKET NOZZLE AND ITS INFLUENCES ON THE MOTOR’S THRUST CURVE

The main goal of this work is to investigate how the angles of a convergent-divergent rocket nozzle influence the thrust curve of a solid-propulsion rocket. The work has been conducted within an academic rocketry team. As there is not clear reasoning on how to define these angles, the present research provides insights on how these geometrical parameters influence the performance of a rocket motor. A 2D-axisymmetric CFD domain is considered, comprising the fluid domain inside and outside the nozzle, to give room for the shock waves to happen and also accommodate the flow. The study comprises a baseline geometry and twelve modified designs, varying the convergent and the divergent angles of the nozzle. Since the convergent diameter must match the chamber diameter, it is fixed. For the divergent diameter, there is no such restriction; therefore, there are two possibilities: a divergent section with the same divergent diameter or with the same length as the baseline. The benchmark thrust curve is generated with a MATLAB code based on solid-fuel modeling and the De Laval theory. The curve is divided into six steady-state simulations, using boundary conditions of mass flow, pressure and temperature at the inlet and pressure and temperature at the outlet. The baseline geometry is simulated in Ansys Fluent and normalized by the MATLAB benchmark. A mesh study selects which mesh and turbulence model to use based on this normalization. The modified geometries are then compared to the baseline. The main quantity of interest is the thrust but quantities such as static pressure and average velocity at the nozzle exit aid the understanding of the changes in thrust.

Considering the Revolution

Considering the Revolution

Marie Guyart de l’Incarnation (1599–1672): le singulier parcours d’une ursuline missionnaire de Tours à Québec. Par Vincent Grégoire

In this slim volume, Vincent Grégoire undertakes to tell the story of Marie de l’Incarnation, renowned seventeenth-century mystic and founder of the Ursulines in French North America, as a ‘femme forte’ who surmounted obstacles both social and religious to become ‘la première missionnaire française en Amérique du nord’ (p. 14). Organized around the theme of obstacles, Grégoire’s book advances an interpretation of Marie de l’Incarnation as an active woman, an agent determined not to shrink before challenges but to overcome them. Adversity, argues Grégoire, was Marie’s daily bread, but ‘l’obstacle a fait Marie, n’ayant pu la défaire’ (p. 23). Following an introductory chapter in which he locates Marie and the Ursulines within the context of post-Tridentine Catholicism and early modern missionary movements, Grégoire proceeds to interrogate five different sorts of obstacles that gave shape to Marie’s religious vocation, each explored in its own chapter: demonic temptation; the perilous transatlantic journey of 1639; her maternal obligations towards the son she abandoned for religious life; cultural and linguistic barriers to teaching in New France; and conflicts with her male ecclesiastical superiors. Throughout, Grégoire gives due attention to Marie’s agency, her determination in the face of challenges, her persistence in surmounting them, and her creativity in refiguring them as opportunities to suffer in imitation of Christ. Given the ways in which Marie (as Grégoire affirms in the chapter on ‘Le Fils sacrifié’) interpreted her own life as one lived in subordination to the uncompromising will of God, one does wonder whether Marie would recognize the portrait constructed here — not that it matters to the validity of Grégoire’s interpretation. Readers both new to Marie de l’Incarnation and familiar with her will find much in Grégoire’s study of interest, including a provocative analysis of Marie’s live sense of demonic presence (which is often elided in studies of this Ursuline mystic) and a thorough analysis of her conflicts with Jesuit Father Vimont and Bishop François de Laval over the rules governing the Ursulines of Quebec. Unsurprisingly, given the brevity of the study, Grégoire passes over some aspects of Marie’s biography too quickly and leaves open and unresolved some promising lines of enquiry. For instance, he tantalizingly notes (as have many before him) that, once in New France, Marie no longer experienced demonic assaults and her mystical experiences waned in intensity, while at the same time acknowledging that for Marie, and others of her time, New France was considered ‘une terre essentiellement sous l’influence du diable’ (p. 49) and the Iroquois believed to be instruments of the devil. ­Exactly how — and to what degree — Marie (and her French, Catholic counterparts in New France) assimilated Indigenous Americans to the devil is worth more analysis than Grégoire gives it here, but perhaps one of the yields of a book like this is to stimulate future research.

Features of Ice-forming Aerosol Generation during the Combustion of Pyrotechnic Composition in the Path of the De Laval Nozzle

Features of Ice-forming Aerosol Generation during the Combustion of Pyrotechnic Composition in the Path of the De Laval Nozzle

A Study on Concepts De-Laval Nozzle using CFD Tool

A device that is used to control the characteristics of fluid is known as a nozzle. Its primary function is to increase the fluid's rate of motion. A traditional De-Laval nozzle will have three distinct parts: a throat, a converging section, and a diverging part. This paper will attempt to detail the bulk of the nozzle concepts developed by De Laval. This paper provides a comprehensive analysis of the nozzle's operational philosophy. In addition, theoretical flow analysis is carried out at a number of locations along the length of the nozzle. The dynamic changes in flow parameters such as pressure, temperature, velocity, and density may be seen with the use of computational fluid dynamics (CFD). The use of CFD is also employed in the simulation of shockwaves.

Attribuer un sens: la diversité des pratiques langagières et les représentations sociales éd. par Kristin Reinke

Reviewed by: Attribuer un sens: la diversité des pratiques langagières et les représentations sociales éd. par Kristin Reinke Amanda Dalola Reinke, Kristin, éd. Attribuer un sens: la diversité des pratiques langagières et les représentations sociales. PU de Laval, 2020. ISBN 978-2-7637-4884-9. Pp. 320. This volume investigates how the sociohistorical—political and cultural—contexts of Francophone North America have influenced the social representations of French-speaking communities, and how these representations have impacted present-day linguistic practices and perceptions of them. With an introduction and ten articles, the collection orders itself according to functional objective. The first five chapters explore the construct of a standard French variety in light of localized variation found in specialized contexts: diatopic phonetic variation in televised interviews, lexical variation in an online dictionary, (morpho)syntactic variation in SMS, age and first language-induced typographical variation in computer-mediated communication, and variation in film dubbing practices in Québec for Québécois audiences. While the first unit of the volume celebrates linguistic diversity via micro-sociolinguistic analyses of practice, the second half discusses the broader social meanings attributed to the cultural diversity of language practices in heterogeneous communities where French is just one of speakers' many possible codes. An investigation of young immigrant Francophones in Montréal, for instance, revealed that first-generation users retained the phonetic features of their first language when speaking French, while subsequent generations did not. Meanwhile, Franco-Ontarian teens who seemed to sample freely from French and English resumptive discourse markers when speaking French—(ça) fait que, donc, alors, so—were found to index their linguistic identity through their rates of use of two variants in particular: so and (ça) fait que. Those who identified as French-English bilinguals used higher rates of so, while those who identified as Francophone instead used higher rates of (ça) fait que. Other chapters explore minority Francophone communities in different locales—Ontario, Alberta, Haiti—to demonstrate that the sociolinguistic identity of a speaker, taken together with the unique identity of their local community, and the regularity and meaningfulness of their repeated interactions with other Francophones in it, are just as significant at predicting patterns of sociolinguistic variation as the often cited phenomenon of language contact. This message contributes to the larger objective of the work, which is not only to represent North American Frenches in plural, contemporary, and nuanced contexts, but to do so veraciously, such that readers are disabused of common misconceptions surrounding language use and variation and the sociocultural mechanisms that motivate them. This text is a useful addition to any curriculum showcasing themes of French (socio)linguistics, language and identity, and/or language variation in digital media. Although the magnitude of its message is greatest when enjoyed together, each of the volume's ten chapters is impressive enough to be read on its own. A celebration of sociolinguistic diversity [End Page 266] in varieties of North American French, this volume more than earns its title for encouraging readers to consider the multifaceted importance of attributing meaning to every level of language and society. [End Page 267] Amanda Dalola University of South Carolina Copyright © 2022 American Association of Teachers of French

Time-Resolved Imaging of Femtosecond Laser-Induced Plasma Expansion in a Nitrogen Microjet

We report on the study of ultrafast laser-induced plasma expansion dynamics in a gas microjet. To this purpose, we focused femtosecond laser pulses on a nitrogen jet produced through a homemade De Laval micronozzle. The laser excitation led to plasma generation with a characteristic spectral line emission at 391 nm. By following the emitted signal with a detection system based on an intensified charge-coupled device (ICCD) we captured the two-dimensional spatial evolution of the photo-excited nitrogen ions with a temporal resolution on the nanosecond time scale. We fabricated the micronozzle on a fused silica substrate by femtosecond laser micromachining. This technique enabled high accuracy and three-dimensional capabilities, thus, providing an ideal platform for developing glass-based microfluidic structures for application to plasma physics and ultrafast spectroscopy.

Geographical Knowledge as Power: The Role of the Society of Jesus and the Society of Foreign Missions of Paris in the Early Exploration of Louisiana

The Society of Jesus and the Society of Foreign Missions of Paris played prominent roles in the early exploration of French Louisiana. The two societies competed over territorial jurisdiction since the presence of their missionaries provided privileged access to the latest geographical data. In times of exploration and colonial territorial expansion, geographical data proved to be an important lever of power, and French missionaries were one of the principal agents of acquiring and disseminating knowledge. We follow the role of the two mentioned missionary societies through the eyes of the Jesuit Father Paul du Ru, the priest of the Society of Foreign Missions of Paris, Francois Le Maire, and two Jesuit travelers, Antoine de Laval and François-Xavier Charlevoix. Their journals, travel narratives, and maps offer an early testimony to Louisiana’s rich history and cultural encounters between European settlers and native nations. This article is based on original research.

Safety of COVID-19 vaccination in patients with polyethylene glycol allergy: A case series

Safety of COVID-19 vaccination in patients with polyethylene glycol allergy: A case series

Hypersonic nozzle for laser-spectroscopy studies at 17 K characterized by resonance-ionization-spectroscopy-based flow mapping

The in-gas-jet laser spectroscopy method relies on the production of uniform and low-temperature gas jets to fully resolve the atomic hyperfine structure and efficiently determine fundamental nuclear properties of short-lived isotopes from, e.g., the hardly accessible actinide and transactinide elements. In this article we present the studies devoted to designing, producing, and characterizing the flow properties of a convergent-divergent (de Laval) hypersonic nozzle with a superior performance for laser spectroscopy applications. A novel flow mapping technique, based on resonance ionization spectroscopy (RIS), has been employed to characterize the local flow properties of an argon gas jet formed by this nozzle, revealing a 61.5-mm long, highly collimated atomic jet at a uniform low temperature of 16.6(5) K [Mach 8.11(12)] that will enable laser spectroscopy experiments on heavy-exotic nuclei with an unprecedented spectral resolution and a high efficiency. These results have been compared with those obtained by planar laser induced fluorescence spectroscopy (PLIFS) studies and show a good agreement between the two techniques and a significant improvement in efficiency of the RIS mapping method with respect to PLIFS. The data are compared to state-of-the-art fluid-dynamics calculations that were carried out to obtain the nozzle contour and simulate its performance, as well as to explain the observation of a possible onset of argon nucleation.

Symmetric and asymmetric shocked gas jets for laser-plasma experiments.

Shocks in supersonic flows offer both high density and sharp density gradients that are used, for instance, for gradient injection in laser-plasma accelerators. We report on a parametric study of oblique shocks created by inserting a straight axisymmetric section at the end of a supersonic "de Laval" nozzle. The effect of different parameters, such as the throat diameter and straight section length on the shock position and density, is studied through computational fluid dynamics (CFD) simulations. Experimental characterizations of a shocked nozzle are compared to CFD simulations and found to be in good agreement. We then introduce a newly designed asymmetric shocked gas jet, where the straight section is only present on one lateral side of the nozzle, thus providing a gas profile well adapted for density transition injection. In this case, full-3D fluid simulations and experimental measurements are compared and show excellent agreement.

PROCESSES AND TECHNOLOGIES OF COLD GAS DYNAMIC SPRAYING OF AGRICULTURAL EQUIPMENT

The article is devoted to the technology of cold gas-dynamic spraying - a relatively new technology for creating functional coatings in which narrowed-expanding nozzles (De Laval nozzles) are used, in which solid powders are sprayed at or close to supersonic speed in the direction of the substrate, where they plastically deform and adhere. Cold gas dynamic spraying is an innovative process that has received widespread scientific interest and industrial applications in the automotive, aerospace and biotechnology industries in recent years. Spraying various powder materials in this way provides protection against corrosion and can increase the mechanical strength and wear resistance of details. With that method it is possible to create functional coatings with different thermal conductivities and electrical conductivities, which can be used as insulation materials, conducting and isolation surface layers of parts, coatings for controlling gaps, restoring and repairing details. The article discusses modern developments in the field of experimental analysis of technologies and processes of cold gas-dynamic spraying, the systems of cold gas-dynamic spraying and coating formation are determined and the parameters and principles of the process are described. The installation for spraying surfaces developed at VNAU is presented and researches and the analysis of possibility of use of a method of a cold gas-dynamic spraying for restoration of details of autotractor equipment of agricultural purpose are carried out.

A Phase II Trial of Eltrombopag in Chronic Myelomonocytic Leukemia (CMML) with Thrombocytopenia

Context: Thrombocytopenia is a frequent complication in CMML associated with worse prognosis (Itzykson JCO 2013, Patnaik Leukemia 2013). Thrombopoietin (TPO) protects HSCs from DNA damage (de Laval Cell Stem Cell 2013). The TPO analog eltrombopag (ELT) has shown efficacy in MDS (Oliva Lancet Hematol 2017). The limited data on ELT in CMML is restricted to a small cohort (n=7) with high risk features, where 4 pts had disease progression during ELT (Ramadan Clin Lymphoma Myeloma Leuk 2016). We report interim results of a multicenter phase 2 trial investigating the efficacy, toxicity and biomarkers of ELT in 25 CMML with platelets (PLT) < 50 x109/L (NCT02323178).Methods: Key inclusion criteria were: WHO 2008 defined HMA-naive CMML, PLT < 50 x109/L, marrow blasts ≤ 5%, IPSS low/int-1 in MD-CMML, and in MP-CMML no or 1 severity criteria (Hb < 10 g/dL, ANC > 16 x109/L, abnormal karyotype, extramedullary disease) ,spleen size < 16 cm. ELT was started at 100 mg/d with escalating doses to 300 mg/d. Platelet Response (HI-P) was evaluated at 12 weeks, according to IWG 2006 criteria, and responders could continue treatment. Gene mutations were analyzed by NGS at inclusion. DNA repair was explored by counting gH2AX foci in CD34+ cells obtained at inclusion, evaluation and study exit.Results: We report on the first 19 evaluable pts (median age 79y, M/F 15/4), all CMML-1 by WHO 2008, including 14 MD-CMML and 5 MP-CMML, with a low/int-1/int-2 CPSS (Such Blood 2013) in 61%, 33% and 6% of pts respectively (resp). Median PLT count was 29 x109/L (IQR 19 - 43.5) and 10 (53%) pts had PLT transfusion dependency (PLT-TD). TET2, RUNX1, ASXL1, SRSF2, PHF6, and RAS pathway mutations were present in 17, 10, 6, 7, 4 and 7 of 18 pts sequenced, resp.The median maximal dose of ELT received was 200 mg/d (IQR: 150 - 300 mg/d). Clinical grade ≥3 toxicities, all cardiovascular or pulmonary, were noted in 5 pts in the first 12 weeks, and biological grade ≥3 toxicities in 6 pts, without grade ≥3 ALT/AST elevation. Six (32%) pts went off study before week 12 because of lack of efficacy (n=2), presence of in circulating blasts (n=1), progression to CMML-2 (n=1), pancreatic cancer (n=1) and patient decision (n=1). All were considered non-responders. At 12 weeks, 12 (63%, 95%CI: 38 - 84) pts had achieved HI-P, including 3/5 MP-CMML and 9/14 MD-CMML (p=1). Responses were obtained in 7/10 pts with baseline PLT-TD and 5/9 pts without PLT-TD (p=0.65). The mutational profile of responders was comparable to that of non-responders except that none of the 4 PHF6mut pts responded (p=0.01). Responders at 12 weeks were receiving a median of 125 mg/d of ELT, compared to 225 mg/d in non-responders.Responders received ELT for a median of 21 weeks (IQR 15 - 38). With a median follow-up of 18 months (95%CI: 16.8 - NR), 11 of the responders discontinued ELT because of loss of efficacy (n=2), patient decision (n=1), death from unrelated causes (n=2), liver toxicity (n=2), renal failure (n=1) and disease progression (n=3). Median response duration was 8 months (95%CI: 5 - NR), with one pt still on treatment with a response lasting more than 14 months. The 12-month cumulative incidence of AML was 19% (95%CI: 4 - 41%) and 12-month progression-free and overall survival (OS) were 41% (95%CI: 23 - 73) and 65% (95%CI: 45-92%). By comparison, in the 21 CMML pts with PLT < 50 x109/L and ≤5% BM blasts from our previous CMML cohort (Itzykson JCO 2013), none of whom received ELT, the 12-month estimates for cumulative incidence of AML and OS were 10% (95%CI 0 - 23%) and 71% (95%CI 47 - 86%), resp. An updated analysis including all 25 pts will be presented.At protocol screening, a higher number of gH2AX foci were seen in CMML bone marrow CD34+ cells (n=14) compared to age-matched controls (n=5, p<0.01), reflecting higher levels of baseline DNA damage. However, in the 5 pts for whom serial bone marrow samples were obtained during ELT, gH2AX foci were reduced in CD34+ cells from all 5 pts, suggesting that in vivo exposure to ELT protected CMML stem/progenitor cells from DNA damage.Conclusion: Our interim results suggest that ELT is manageable in CMML pts with no excess of marrow blasts and thrombocytopenia and results in a high response rate, with no obvious increase in disease progression, though prolonged responses seem infrequent. ELT could potentially protect CMML stem/progenitor cells from DNA damage. Larger pt numbers and longer follow-up are however required to determine precisely the role of ELT in thrombocytopenic CMML pts. DisclosuresItzykson:Janssen: Research Funding; Novartis: Research Funding. Fenaux:Astex: Honoraria, Research Funding; Astex: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Amgen: Honoraria, Research Funding.

Rapid Quantification of Sars-Cov-2 Antibodies with a Portable Surface Plasmon Resonance Biosensor

The development of rapid, accurate and affordable diagnostic tests is essential for screening the population in order to properly manage and control the spread of the COVID-19 pandemic caused by the novel coronavirus (SARS-CoV-2). Current diagnostic techniques rely on tests which are time-consuming, must be performed in a specialized laboratory, and are limited in terms of sensitivity and specificity to active infection. Therefore, they don’t provide any information on previous exposure to the virus.Optical biosensors have the potential to overcome the current limitations in diagnostic techniques for COVID-19. My research project aims to develop a new rapid and precise analytical method using surface plasmon resonance (SPR) to detect anti-SARS-CoV-2 antibodies directly in crude sample. The SPR biosensor used in this project is based on the Kretschmann configuration. When the polarized light travels from the higher refractive index medium to the lower refractive index medium, the total internal reflection occurs. This leads to the formation of evanescent waves which are responsible for the excitation of the surface plasmons. Changes in the refractive index of the sample solution vary the resonance wavelength. Therefore, the adsorption-desorption activities on the surface of the sensor can be analyzed by tracking the wavelength location of the SPR band over time. The SPR technique allows real-time and label-free detection of molecular interactions. It is also very sensitive, can reduce test time to minutes, and can be used at the point of care for infectious diseases. Serological test involves the direct quantification of antibodies by exposing them to the virus protein immobilized on the surface of the sensor. Antibodies to SARS-CoV-2 are produced by the immune system within days or even weeks after viral infection and remain at an elevated level for months. Many research works in the development and evaluation of coronavirus vaccines require antibody testing for characterization of the affinity and kinetics of the immune response during vaccine development. Therefore, the development of a robust method by using SPR for performing serological tests is necessary. In this project, the various analytical parameters are optimized in order to increase the specific interactions between SARS-CoV-2 proteins and human antibodies and to decrease the non-specific adsorptions of other proteins to ensure a sensitive and specific test. Different COVID-19 proteins, such as the Nucleocapsid, the S1 domain of the Spike, the RBD domain of the Spike and the complete Spike were immobilized on the gold surface functionalized with the peptides 3-MPA-LHDLHD-OH to detect animal antibodies raised against each protein in the buffer and human serum. In each case, the immobilization conditions, such as concentration, chemistry and pH were optimized and detection limits were calculated for each antibody of animal origin. Although the direct detection of antibodies worked well, the use of a secondary antibody improved the results significantly in human serum. The validation of tests with animal antibodies made it possible to move on to the next step, which consists in using this detection method with a first cohort of clinical samples provided by the Centre hospitalier de l’Université de Laval (CHUL) to validate my research work in a clinical setting.