Agnès Duri

Charlène Fabre

Patrice Buche

Claire Mayer

for welcoming me and giving me their enthusiasm and support throughout this internship. I thank you for never ceasing to show confidence in my work and my abilities. This has been a new and different experience for me, working for the first time outside my home country. I have learned so much, and I have grown and acquired new knowledge and professional experience.

I'm very thankful to INRAE for the opportunity they gave me to participate in this interesting project. Furthermore, thanks to the UMR IATE and everyone working there, for welcoming me and helping me. Likewise, I would like to thank Christophe Fernandez et Julien Couteaux from IM2 in Bordeaux for their valuable and essential support in the realization of my internship.

Thanks to Agnès, for always encouraging me to do my best and having the best availability to help. Thanks to Charlène, for dedicating her time to training me with all the types of equipment and measuring devices that I used throughout the internship. Thanks to Patrice, for his

Introduction

Intending to preserve knowledge and create more accessible and verified information, the Joint Research Unit for Agropolymer Engineering and Emerging Technologies (UMR IATE) proposed the conception of knowledge books (LDC, Livres des Connaissances). An LDC is an electronic hypermedia tool accessible online that gathers information to understand and learn about a specific concept or subject.

The main objective of this internship is to design a prototype of "PowderLib" whose main component is an LDC, related to the production and the characterization of vegetal powders, following an open science approach. That means that Data Papers, which contain experimental data and protocols made by the researchers in UMR IATE are directly accessible from the LDC. These vegetal powders come from agricultural and wood by-products. They can gain value thanks to dry fractionation processes; the ultra-fine powders obtained have shown promising functionalities in energy and material applications. In UMR IATE, much research in milling, separation, and drying processes has been conducted in the past years, with the aim of further understanding the relationship between the processes and the raw materials. Since these unitary operations consume a lot of energy to obtain the targeted particle size (~15-50 µm) (Figure 1), it is imperative to find new solutions to obtain the same result with a lower carbon footprint. Also, the characterization of these powders is an important variable in the studies, considering the impact their physical and biochemical properties have on the procedures. This internship is a knowledge engineering project, willing to spread the information to anyone who can be interested in the production of vegetal powders. Four main target groups were identified as potential users of Powderlib; 1) students of master's degrees or engineering, 2) data scientists, 3) company engineers, and 4) experts in the domain of powders. PowderLib's tools could be useful in many sectors that process powders, including agri-food, pharmaceuticals, composite materials, and biomass energy valorization. A series of interviews with future users were conducted to ensure that the LDC will answer their needs.

Since the objective is to provide information allowing a better understanding of the processes, the interface will be visual and easy to understand. Also, to address requirements expressed by experts in the domain of powders, a few decision trees will be developed with the Capex software tool which is the second component of PowderLib. These decision trees will help in solving powder-quality problems. The navigation between the knowledge book and decision trees facilitates information interlinking. Finally, PowderLib will be written in English to position it in an international scope.

A series of experiments of dry fractionation were conducted with the aim of better understanding the procedures done at UMR. The resulting powders will be characterized by loss of weight, humidity, and particle size and then stored to be used later on in the project Granothèque. This project collects scientific information about vegetal powders. The complete analysis of the results will not be performed throughout this internship.

The internship is foreseen to be conducted from the 21st of March to the 26th of August, this report shows only the progress done until the date of defense. The planning of the internship is shown in Appendix 1. The report is divided into 4 main sections, the state of the art, the methodology followed, results based on use-cases, and conclusions.

Structure of the host laboratory

The Joint Research Unit for Agropolymer Engineering and Emerging Technologies (UMR IATE 1208) in Montpellier brings together agents from INRAE (l'Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement), the University of Montpellier, and l'Institut Agro Montpellier. It includes about 90 permanent and 60 non-permanent staff divided into 10 teams (see Appendix 2). This unit studies the processing and exploitation of renewable resources from the forestry and agricultural sectors. Their main expertise is biochemistry, physical chemistry, process engineering, biotechnology, and numerical and computational modeling.

My internship is at the interface of 3 research teams, in which I work in collective to create the project of PowederLib. The PhyProDiv team (Physics of Processes and Divided Materials of Plant Origin) is interested in the controlled generation of plant biomass particles and the characterization of the physical and mechanical behavior within powders, dense suspensions, or filled composites from an experimental and numerical approach. The ICO team (Ingénierie des Connaissances) conceptualizes and develops methods and tools to create knowledge engineering projects, to support collective decision-making in agri-food systems. And the PLANET platform works in the comprehension and studying of the procedures of dry fractionation.

Four contributors participated in the supervision of the internship. Agnès DURI (PhyProDiv) for the characterization of powders and the realization of videos of the experimental protocols. Patrice BUCHE (ICO) is the co-creator of Capex, one of the software used during my internship. Claire MAYER (PhyProDiv) and Charlène FABRE (PLANET) for the milling and separation part. In addition, Christophe FERNANDEZ and Julien COUTEAUX from the I2M team in Bordeaux participated by giving us the training on the informatics programs, especially in the software MakeBook. The project was financed by DataSusFood, a project funded by the French Agency for Research in which ICO is involved.

State of the art

Vegetal powder research

The vegetal powder world includes any powder coming from an organic source. But in the PLANET platform, the lignocellulosic biomass (LB) is the main raw material used in their research. LB is composed of cellulose (~20-60% ), hemicelluloses (~10-40%), and lignin (~10-40%) (Mayer-Laigle, C., Blanc, N., et al, 2018). Some examples of LB used in the research are wheat straw, wood, flax fiber, hemp fiber, and hemp hurds.

Usually, this biomass is considered as a waste, but it has been shown to be a great alternative to petroleum-based products. Some of the high-tech applications can be the production of bioethanol and composite material. But in order to exploit all the potential of LB, it is necessary to reduce its size to an ultra-fine powder (Mayer-Laigle C., Rajaonarivony, R., et al, 2018). To accomplish that goal it is necessary to undertake extensive milling itineraries that take even hours to achieve the targeted particle size.

The research is based mainly on finding solutions to reduce the time and energy consumption of the procedures of milling, drying, and separation. The present conditions of these procedures affect the overall profitability of the final product (Mayer-Laigle C., Rajaonarivony, R., et al, 2018). This can be done by analyzing physicochemical characteristics of the raw materials, type of mechanical stress, the operational parameters, and the type of drying technique (Mayer-Laigle, C., Blanc, N., et al, 2018).

Also, the study of the physicochemical characteristics and rheological properties of the raw materials is a key step to fully understand the phenomena occurring during fragmentation processes. Some examples of the analyses performed are particle size distribution, shape, specific surface area, and powder agglomeration (Rajaonarivony, K., et al., 2019). This type of valuable information coming from the research done at IATE, presented in the form of data papers, is the one that we are most interested in showing in the LDC because it can constitute a guide for the users.

LDC DOCaMEx as a guide and the Data Papers

DOCaMEx is a tool composed of two software components: an LDC generated with the Make Book tool created by the I2M team (Suciu et al., 2021) and Capex, a decision software tool created by the ICO team (Buche et al., 2019). DOCaMEx has been applied in the field of AOP French cheeses and its objective was to reduce the loss or distortion of the know-how of this domain.

The structure of an LDC follows a specific organization, relying on two main types of documents: conceptual maps (Cmaps) and knowledge sheets (FC). The conceptual maps graphically represent a set of concepts and the semantic relationships between them. The knowledge sheets provide more detail about the concept by using text and multimedia content such as images, sound, videos, equations, etc.

The data papers published by the PLANET platform are a key element of PowderLib: Milling itineraries dataset for a collection of crop and wood by-products and granulometric properties of the resulting powders (Fabre, C., Buche, P., et al., 2020) and Biocomposites from poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and lignocellulosic fillers: Processes stored in data warehouse structured by an ontology (Munch, M., Buche, P., et at.,2022). The data paper by Fabre, C., Buche, P., et al., 2020 shows the milling steps, the equipment used, its operating parameters, and the granulometric properties (D10, D50, D90, span, and specific surface area) of the 19 by-products processed. The data paper by Munch, M., Buche, P., et at.,2022 presents 88 formulations to create biocomposites of mixed PHBV and LB powders. It includes the steps and the observations measured (crystallization, melting temperature of biocomposites, water vapor permeability, and mechanical properties.

Methodology

The multidisciplinary methodology which has been designed and followed in this internship is shown in Figure 2. I started with the identification of users that could be interested in PowderLib, and the realization of interviews to determine the possible use cases.

Then, I was formed in the different procedures, methods, and informatics programs that gave me the tools to better understand and conduct this project.

For the conception of PowderLib, I implemented an iterative process in the realization of the software's inter-connected components: conceptual maps (Cmaps), knowledge sheets (FC), decision trees (Capex), and the glossary.

The step of content verification with supervisors was followed all along the internship during weekly meetings.

The validation of the content through use-cases will show if the users are able to solve a specific problem or situation.

The evaluation with cognitive load tests will not be discussed in this report because this step is scheduled after the date of the defense.

Identification and interviews with future users

The main objective of PowderLib is to create a tool for people who are interested in learning about vegetal powders or finding a solution to problems in powder production. The first task was to identify these users and to visualize roughly in which scenario they can take advantage of this new LDC. The users can be divided into two main categories: the experts of the domain and the non-experts.

The experts in the domain are researchers who could be very interested in finding new articles. The non-experts could be master's degree students, data scientists, and company engineers. The master's degree students can use the website as a reliable resource of information for university classes. The data scientist can have access to the data sets and also to essential information to comprehend the variables of the data paper. The company engineer can use the information to solve different problems in their production line.

So in order to be able to answer the precise needs of the users, a series of interviews were scheduled. This will help to know the perspectives and expectations of the users on the tool developed. This exercise helped settle the type of information and how it will be presented on the platform. The list of interviewees and the topics discussed are presented in Table 1. The interview was first composed of a brief presentation of the LDC and the purpose of PowderLib. With the aim of giving the interviewee information to visualize and imagine the extent the project can have. After the presentation of the project, a series of questions were posed to the interviewee to initiate a further discussion about what they considered relevant to include. For example, some questions were:

• What is your opinion about the main topics selected for the home page of PowderLib?

• Is there any topic you would consider adding or modifying? If yes, please specify.

• What is your opinion on the design and presentation of the graphic content?

• Do you find the concept of Cmaps, FCs, and decision trees easy to understand?

• Is it convenient for you that PowderLib is a website?

Training and experimentation at UMR IATE

With the objective of better understanding the procedures of drying, milling, separation, and powder characterization, I performed a series of experiments. It is a fundamental part of the internship because it helps to correctly understand the principles and the mechanism of the types of equipment. By conducting these experiments it was much easier to imagine the different scenarios that the users could encounter and the potential problems they could have. All the milling procedures were done according to the specification of the PLANET platform.

The raw materials used were rice husk, hemp core, and pine bark, by-products from agriculture and the wood industry. All the raw materials were already pre-milled (size <5cm) and most of the time a drying treatment in an oven was applied, at 60ºC between 12 and 48h. Except for the pine bark which was sun-dried prior to oven-dried.

For the coarse milling, the knife mill Retsch SM300 (Appendix 3) was used. The product passes into the milling chamber where there are double counter knives. In this setup, shear forces and cutting are the main milling mechanisms. For each experiment, a grid of 2 mm was used and fixed to a velocity of 3000 rpm.

For the intermediate milling, the Alpine UPZ100 station (Appendix 4) was used with the hammer configuration. In this case, impact and shear are the main milling mechanisms. This mill needs to be fed with a product with a particle size below 2mm. The ground powders obtained had a particle size of approximately 0.3 mm.

Additionally, two ball mills were used to achieve a much finer particle size: the SWECO (Appendix 5) and the FEMAG (Appendix 6). Both use compression and attrition as the main milling mechanisms. The SWECO uses ceramic pellets as grinding media made with 2 different geometrical shapes (50 %/W spheres and 50 %/W cylinders). The motor produces a vibrational movement that favors the distribution of the product over the entire mass of the media and allows a maximum surface contact (FABRE, C, et al, 2017). The FEMAG is a costume-made device designed by the Planet platform. It uses sphere-shaped stainless steel media. The FEMAG works by rotation of a tank which leads to the motion of the media. This mill can achieve particle sizes up to 2 µm.

During and after all the experimentations, the ground powders were characterized. Particle size, moisture content, and weight are measured (Appendix 7). The particle size measurement was performed with the laser particle size analyzer (LD 13 320 XR Beckman Coulter, Appendix 8), which determines the particle size distribution by laser diffraction. Some advantages of using this device are a wide range of analysis (from some mm to nm), the speed of measurement, and more detailed results in comparison to the sieves method (FABRE, C., & MARAVAL, G., 2021). The moisture content was measured with an infrared scale (Precisa XM60, Appendix 9), known as the "rapid" test.

Finally, for each device used, a video was recorded with an explanation of its principles and functionalities. These videos will be added to the LDC in the next steps scheduled after the defense of the internship.

Training on informatics programs

With the help of the I2M team in Bordeaux who designed Make Book software and the ICO team who designed Capex, we received training regarding the different computer programs needed to create the content of PowderLib. The required software are FreePlan, Capex, Cmap Tool, and Make Book.

Freeplan and Capex are used to create the decision trees. Freeplan is a mind mapping software that helps to create the draft file of a decision tree. In the draft file, the text is associated with nodes that create the link between the different ideas, this procedure creates the branches of the decision tree. When the information in the Freeplane document is correct, the document must be converted into a Markdown (MD) file. Then the MD file can be uploaded to Capex. Capex is the online platform that transforms the MD file into the final decision tree that will be visualized by the users.

Concerning the LDC, for the design and creation of Cmaps, one of the most important steps was to determine which modeling software was the most practical and efficient. The decision was made between PowerPoint, Canva, and Cmap Tool. In Table 2, we can see the pros and cons of these options.

Creation of Cmaps

The Cmaps developed for this LDC were created by reusing and extending existing templates, such as Figure 4. These templates were provided by the I2M team, in a document including an explanation of the methodology to correctly create a Cmap. As said before, the principle of a Cmap is to use graphics to organize and represent the information. But depending on the domain, it is possible to have a certain freedom to arrange or change the semantic concepts. Nevertheless, it must follow an objective and be consistent according to the targeted audience (Team I2M, 2021). In this stage, we start to define standard terms that will become keywords defined in a glossary (see section 4.4.4). Also, the information displayed in the Cmaps must be concise and clear, to avoid disorientation and possible cognitive load on the user (Team I2M, 2021).

The steps to create a Cmap are 1. Choose the main concept 2. Write all the sub-concepts that can describe it 3. Organize sub-concepts into categories 4. Define the relevant relationships to relate the main concept to the sub-concepts 5. Carry out the bibliographic research on the selected topic 6. Make a verification of the Cmap with the supervisors Even though PowerPoint is not going to be the final software to produce the SVG image, it was very useful to make the draft and visualize all the Cmaps in one document. So, the Ppt document will serve as a basis when the project is continued by someone else after the end of my internship (Appendix 10). Indeed all the information for the conception of additional Cmaps is gathered there. Additionally, the ppt was used as a tool to exchange with the supervisors. So the steps to edit a Cmap were to modify the base document in Ppt, modify it in CmapTool, redownload it as SVG, and re-uploaded to MakeBook. This series of steps guaranteed a better organization but with the downside of being very time-consuming. This is because sometimes the corrections appear gradually and some Cmaps could need an edition or correction frequently. For example, some Cmaps were edited and re-uploaded up to 15 different times.

Creation of FCs

The process to create an FC is a little bit different, it is the only type of document that is directly created in MakeBook. This means that the presentation format will be the same for every FC and generated by the software. The FCs are a more detailed explanation of a certain topic, so it is possible to develop a more complex idea. It can be accompanied by images, equations, sounds, or videos. Just as the Cmaps, the FCs need constant editing.

Creation of decision trees

As mentioned before, the decision trees were firstly done in Freeplane. The methodology was to select a problem/default, for example, "obtaining a particle size too large compared to the targeted one". So based on the issue, meetings with Charlene FABRE were scheduled to brainstorm and gather all the possible causes and the solutions to this defect. After having finished the decision tree, the MD document is uploaded to Capex. It is possible to link the decision trees of the Capex site to the elements (FCs or Cmaps) of the MakeBook site. This creates a direct relationship between the two components of PowderLib and the user can navigate between the two websites.

In the decision tree in Capex, the user can navigate between the different possible scenarios until it arrives at a "corrective action" (Figure 5) or a "compensatory action" (Figure 6). Corrective actions will show a "long-term" solution to the problem and a compensatory action will show the "instant" reaction to have in these situations just to solve it in that particular moment of a given experiment.

Figure 5. Logo of a corrective action Figure 6. Logo of a compensatory action

Creation of the glossary

A glossary was made to help with the standardization of terminology and the ease of understanding of the terms. A selection of keywords was chosen to be defined in English since it is the main language, but the glossary also provides a translation in French and Spanish.

A bibliographic research was conducted to obtain the definitions and the search engine Web of Science was used to get access to scientific papers. The research of the terms wasn't easy, because each definition could be different depending on the context and the field. So it takes not only the time to find a definition, but also to verify if it is the correct one in the context of vegetal powders.

I directly translate into French and Spanish with the support of online software: Reverso and Deepl. Likewise, if relevant, some synonyms could be added to some definitions. A CSV document in Open Office was created as the editing software for the glossary. This type of format helps to preserve the accents used in French and Spanish, unlike Excel which tends to distort the characters.

The final terms will also be used in other projects, such as an ontology of biorefinery. The definitions will help to enrich the existing terms. This BIOREFINERY ontology is available in INRAE dataverse (https://doi.org/10.15454/X2MOWO, version 2.0) and Agroportal (http://agroportal.lirmm.fr/ontologies/BIOREFINERY, version 2.1). It permits vocabulary standardization in order to minimize ambiguities in the datasets published in data papers.

Evaluation of the prototype

Evaluation of use-cases

In order to evaluate if PowderLib does answer the needs of the users, it is necessary to establish use-cases. These use-cases are scenarios in which we guess a question that a user may ask and try to see if the information does lead to a valid answer. We propose 3 use-cases presented in the results section.

Evaluation tests

The final step and maybe one of the most important is the evaluation with users. This part of the internship will be developed starting the second week of July. This will be done by performing a series of interviews with a questionnaire. The results of the questionnaires will indicate the level of comprehension/retention of the information, the cognitive load, and the disorientation. The steps identify for this task are

Results

The access to the prototype of the PowderLib website is available at the next link, https://icotest.iate.inra.fr/powderlib_portail/ (user: testPowderLib, password: secret). In the portal (Figure 7), there is access to both the LDC and Capex.

A total of 14 Cmaps, 12 FCs, 2 audios, 2 Capex decision trees, and the information of 2 data papers were integrated into the site until the date of the defense. In this report, only some of the Cmaps, FCs, and decision trees will be shown according to the 3 use cases priorly defined.

Home page

As mentioned before, one of the first steps was to create the home page (Figure 9). The design, organization, and main topics were based on the homepage of DOCaMEx (section 3.2). The choice of the sub-topics was a complex reflection because the vegetal powder covers a large field. This reflection process and the final selection of sub-topics were coordinated by the supervisors and guided by the resulting discussion with some interviewees. Because PowderLib deals with the production of vegetal powders, the processes considered to be explained are drying, milling, and separation. The differentiation between a process and a phenomenon was based on the fact that the processes correspond to unit operations in which several phenomena can occur alone or in combination. In addition, phenomena can be induced by the process or on the contrary unwanted. Each phenomenon will be related to one or several processes. At this stage, we selected 6 phenomena: absorption/ desorption (involved in drying), comminution, agglomeration (involved in milling), triboelectric effect, cohesion, and flowing (involved in milling and separation).

The characterization topic is one of the most important ones. A lot of brainstorming and re-structuring was done because it is a complex and vast section. Finally, after several iterative steps, this topic was divided into 3 groups: 1) The intrinsic properties of the powder correspond to the properties measured when there is no interaction between the particles. This category gathers morphology, affinity with water, biochemical, and matter structure properties.

2) The bulk properties of the particles are the result of the combination of several intrinsic properties and/or interactions between particles. This category regroups rheology, mechanical, hydro-textural, and electrostatic properties.

3) The scale of the process gathers properties resulting from the interaction between particles/particles and particles/processes. The other topics included in PowderLib are displayed on the home page but the Cmaps cannot be all completed during this internship. The raw materials were placed into topics according to the way they are obtained. For the manufacturing topic, the sub-topics are quality, performance indicators, regulation/ guidelines, and defaults. The products and applications can be extensive, but we focus here on the main application developed by the UMR IATE in the past years: materials, green chemistry, energy, and food feed. The open science approach of PowderLib gives the users access to the data papers produced by the Planet platform. Figure 10. shows the resulting Cmap of one of the data papers. Thanks to MakeBook it is possible to define a hyperlink to the DOI, marked with the HTTP (green circle) symbol as shown in Figure 10. so the user has direct access to the article. In this use case, the user wants to know the variables measured in the data paper. So in the Cmap, we can easily find this information: particle size distribution and specific surface area. Furthermore, since it is possible to link a Cmap with other Cmaps or FCs to enrich the topic (red circle in Figure 10), the Cmap of this data paper is directly linked with the FC of particle size analysis (Appendix 12). With this utility, the user is able to learn about this variable. According to the interviewee Melanie MUNCH, this is an important feature that will help the data scientist to comprehend the data set that he/she will analyze. The design of the Cmaps patterns associated with data papers is an original contribution of my internship which provides a rapid overview of the data paper's content.

Use-case: Data Scientist and data papers

Use-case: student

Situation: A university student needs to find information about the milling procedure.

Question: What are the parameters we can control for a milling machine? What is comminution? When the student enters PowderLib, he/she can open the Cmap of milling, shown in Figure 11. The reading sense of the Cmaps always starts from the top to the bottom. For example, "Milling" "is controlled by" "milling parameters". "Milling" "has as default" "undesired agglomeration of particles", etc. The most important and basic information about the milling process is shown in the Cmap. In order to enter more in detail about a certain sub-topic in the Cmap, the user can navigate between the different hyperlinks. For example, next to the text of "milling parameters" he/she can find the logo of the FC as shown in Figure 11. Once he/she clicks on the link, the FC of milling parameters (Figure 12) will open in a pop-up window. In this FC, he/she will find the answer to their first question: speed of rotation, vibration, shear forces, and feed rate. Some other features of an FC are in the bottom part of Figure 12: the author of the FC, the groups or LDC that is related to that FC, the keywords, and the bibliographic references. Finally, to solve the second question he/she can easily access the glossary through the menu "Glossary" on the left of the website (Appendix 13). There, a list of all the definitions is displayed and he/she will find the definition to comminution (Figure 13). The glossary has 30 keywords, and their definitions are being uploaded to the MakeBook platform. The format used in the CSV document to define each keyword is shown in Appendix 14:

Use-case: expert of domain

Situation: A researcher is having problems with the step of coarse milling, the particle size is not getting reduced as it should. Question: How can I achieve the targeted particle size in coarse milling? A total of two Capex decision trees were done. Each decision tree will represent a different type of problem and the possible variations it can have. The user can navigate between the possible causes until it finds the one that fits their situation. At the end of each sequence, the user will arrive at a corrective action or a compensatory action.

For example, Figure 14 shows the decision tree for the defect: "Particles too large in comparison to the expected median particle size {coarse grinding, SM100, SM300}", the user can select between the first two decisions 1) mill setting not suitable, 2) the engine consumes too much energy. If the user selects option 1, another series of options will appear and if the user selects "feed rate too high" the corrective/ compensatory actions will appear.

In this case, one of the corrective actions is to check the noise of the mill (green circle). Two recordings were made to help the user identify the difference between a good motor sound and the sound of a forced motor. This is a perfect example of how Capex and the LDC can be interrelated, the sounds are uploaded through MakeBook (to the LDC) and by doing a simple coding technique, the sounds can be linked to the decision tree. The access to the recordings is shown in Figure 14 in the green circle as two blue squares. With this information, the user can find the solution to their coarse milling problem.

Figure 14. Example of the decision tree "Particles too large in comparison to the expected median particle size {coarse grinding, SM100, SM300}"

Conclusion

The main objective was to create a prototype of PowderLib. The conception of an LDC can take several years, because of the amount of information that is necessary to cover. So within the time established for the internship, the resulting prototype is on a good track. Having the websites of the LDC and of Capex is a very tangible result of this objective.

The experimentations with the processes were very interesting. It helped me to gather ideas and to better understand the processes and the know-how of the UMR IATE. There were some minor drawbacks during the experimentations but mainly all of them were accomplished adequately. Finally, the data gathered in this step of the internship will be treated in the Granotheque project which gathers in particular all the data on the powder characterization. Also, the interviews helped a lot to correctly ground the ideas. Knowing what the users expected of PowderLib was essential. I feel that the result would not be the same without this feedback.

As mentioned before, the results shown are just a partial outcome of the internship. There are still a few Cmaps, the evaluation with users, and some powder characterizations that are scheduled to be done in the remaining 2 months of the internship.

The experience at UMR IATE has been very enriching, it was the first time I had the opportunity to work in a research laboratory, especially outside of my home country. This has given me a lot of new skills and knowledge. I am learning a lot about how research is done, the stakes, and the compromise. I appreciate the opportunity to be involved in a realization of a project like this and to collaborate with my supervisors and all the professionals who were involved with the project. With my supervisors, I feel my opinions and contributions are heard and appreciated. I have greatly valued what I have learned from them. I feel like I am working with my capabilities of responsibility and organization, as this was the most challenging part for me. Also, this internship helped me tremendously with my French and English skills. As well as complimenting my knowledge in the powders field, as I already had experience, this internship gave me a wider perspective.

In the future, I see myself still working on projects involved with the improvement of the environment, but not necessarily in the research field. I feel drawn to working more directly in the industry. I look forward to the day PowderLib will be finally ready to be shared with the world. Résumé : PowderLib est un nouvel outil logiciel proposé pour aider à la diffusion de la recherche scientifique dans le domaine de la production et de la caractérisation des poudres végétales avec une approche de science ouverte. PowderLib est composé de deux logiciels : un livre de connaissances (LDC) et le système Capex. Un LDC, qui est un portail électronique avec des contenus hypermédia, a pour objectif de diffuser les connaissances relatives à une filière ou à une discipline. Capex est un système générique d'aide à la décision facilitant un choix technologique afin d'atteindre une certaine qualité de produit ou de résoudre un défaut dans un processus de transformation. Aujourd'hui, l'intérêt pour les poudres végétales augmente très significativement, avec de nombreux domaines d'application (par exemple, le bioéthanol ou les biomatériaux). Toutefois, le processus d'obtention de ces poudres (séchage, broyage, et séparation) peut présenter des défauts, l'information contenue dans PowderLib pourra aider à les résoudre.

List of Tables

List of Figures

Pendant ce stage, l'objectif était de créer un prototype de PowderLib. Afin d'acquérir les compétences nécessaires pour cela, une série de formations sur les procédures de broyage, de caractérisation des poudres, et de logiciels informatiques a été effectuée. Ensuite, le contenu de PowderLib a été créé en s'appuyant sur des entretiens avec des utilisateurs ciblés, en définissant des cas d'utilisation, en créant des cartes conceptuelles, des fiches de connaissances et en concevant des arbres de décision avec des experts du domaine pour résoudre des problèmes de production. Le prototype PowderLib enfin été évalué pour 3 cas d'utilisation.

Mots clés : Poudres végétales, livre de connaissances, fractionnement par voie sèche, caractérisation des poudres, arbre de décision.

Figure 1 .

 1 Figure 1. Exemplification of how the energy consumption increases in relation to the particle size reduction (Mayer-Laigle C., Rajaonarivony, R., et al, 2018).

Figure 2 .

 2 Figure 2. Workflow of the internship

Figure 3 .

 3 Figure 3. Different types of possible documents to upload/create in MakeBook

Figure 4 .

 4 Figure 4. Template of a Cmap from DOCaMEx (Team I2M, 2021).

1 .

 1 Presentation of the instructions and the tool PowderLib, 2. Fill in the information sheet, 3. Single choice pre-test, 4. Free navigation on the website (20 min), 5. Cognitive load and disorientation test (Appendix 11), 6. Scenario-based navigation (20 min), 7. Single choice post-test, a second time, 8. Cognitive load and disorientation test, a second time, 9. Review questionnaire, 10. Optional questions.

Figure 7 .

 7 Figure 7. The main page of the portal PowderLib

Figure 8 .

 8 Figure 8. PowderLib logo

Figure 9 .

 9 Figure 9. Home page of PowderLib

  Situation: A data scientist enters PowderLib to find more information about a data paper. Question: How and what are the variables measured?

Figure 10 .

 10 Figure 10. Example of a Cmap of the data paper Milling itineraries

Figure 11 .

 11 Figure 11. Cmap of milling

Figure 12 .

 12 Figure 12. FC of "milling parameters"

Figure 13 .

 13 Figure 13. The pop-up window for the definition of Comminution

Figure 1 .Figure 10 .Figure 11 .

 11011 Figure 1. Exemplification of how the energy consumption increases in relation to the particle size reduction (Mayer-Laigle C., Rajaonarivony, R., et al, 2018) 4

Table 1 .

 1 List of interviewees

	Interviewee	Type of user	Main topic discussed
	Melanie MUNCH	Data scientist	What information is important for a data scientist to find in PowderLib to
			conduct an analysis of a data paper.
	Magali WEBER and	Domain expert	Glossary: methodology to find scientific definitions.
	Caroline BANDU
	Leslie LHOMOND	Domain expert	Agroalimentary point of view: durum wheat example.

Thierry RUIZ Domain expert

Organization and selection of the most important characterization methods.

Luis CASTAÑO Enterprise engineer

Possible defects and problems encountered through the milling, drying, and separation procedures.

Table 2 .

 2 Comparison of different modeling software.The final decision was mainly based on the possibility to transform the final image into a scalable vector graphic (SVG). The SVG format is preferable because it uses vectors to produce the image and this helps retain a better quality of the artwork. Indeed, a simple portable network graphic format (PNG) under 900 pixels can get distorted if PowderLib is viewed on a phone or a tablet. So with this in mind, PowerPoint and the free version of Canva were dismissed. Afterward, even if the paying version of Canva has a much wider design selection, it was not retained as an option because of its price. In conclusion, Cmap Tool is the knowledge modeling toolkit that was selected to create the design of the Cmaps. In the beginning, Cmap Tool was difficult to understand and maneuver, but it became a little bit easier with time. Lastly, the platform that allows putting together all the different inputs is MakeBook. This platform generates the HTML pages of the website. Figure3. shows the different types of documents that can be uploaded and the logos used for each hyperlink. It has editing tools that are very easy to use:

	Software	Facility to use	Design options	Price	SVG option
	PowerPoint	+ + +	+ +	Free with the INRAE account	No
	Free Canva	+ + +	+ + +	Free	No
	Paying Canva	+ + +	+ + + +	119,99 US$ / year (5 users)	Yes
	Cmap Tool	+ +	+ +	Free	Yes

Table Title PageTable 1 .

 Title1 List of interviewees 8

Table 2 .

 2 Comparison of different modeling software 10

Acknowledgments

Summary

Bibliography

Glossary

__________________________________________________________________________

Production and characterization of vegetable powders in an open science approach

Abstract: PowderLib is a new software tool proposed to help with the dissemination of scientific research in the field of production and characterization of vegetal powders with an open science approach. PowderLib is composed of two software components: a knowledge book (LDC) and the Capex system. An LDC is an electronic portal with hypermedia contents and has the objective of spreading knowledge of a specific industry or discipline. Capex is a generic decision support system that helps to choose the right technological action in order to reach a certain product quality or to solve a default in a transformation process. Nowadays innovation in the area of vegetal powders is increasing, with many applications of interest (eg. bioethanol or biomaterials). The process of obtaining such powders (drying, milling, and separation) can present problems, the information in PowderLib will help to solve these issues.

During this internship, the objective was to create a prototype of PowderLib. In order to acquire the necessary skills for this, a series of training on milling procedures, powder characterization, and informatics software were performed. Then the content of PowderLib was created by performing interviews with targeted users, defining use-cases, creating conceptual maps, knowledge sheets, and designing decision trees with domain experts to solve production problems. The final result was the creation and assessment of a prototype of PowderLib which was evaluated by 3 use-cases.

Keywords: Vegetal powders, knowledge book, dry fractionation, powder characterization, decision trees.

Master 1 Ingénierie pour l'éco-Conception des Aliments (ICOA)


Pascal Antoine
email: pascal.antoine@univ-lille.fr

Eva Andreotti

Anne Congard

Positive psychology intervention for couples: A pilot study

In this randomized study, a multicomponent, theory-driven, autonomous self-help positive psychology intervention (PPI) for couples was examined. This intervention was not designed for distressed couples but rather to address autonomous couples with a good initial level of functioning who, nonetheless, wished to improve it. The objective was to assess the efficacy of the PPI on satisfaction with life, affective life, communication patterns, and dyadic adjustment in each member of the dyad. The 4week PPI encompassed dyadic and individual daily activities. Thirty-eight couples were assigned to an intervention group (n = 20 couples) or a waiting list control (WLC) group (n = 18 couples). Assessments were conducted prior to and after the PPI, with an immediate post-test and a follow-up. Ninety-two percent of the PPI was completed by the participants. Linear mixed models revealed improvements in posi-tive emotions, communication patterns of mutuality, and dyadic adjustment from the pretest to the immediate post-test in the intervention group compared with the WLC group. Effects of dyadic adjustment were maintained from pretest to 1-month follow-up in the intervention group. This pilot study suggests that the realization of intentional dyadic activities presents an interesting approach to contribute to individ-ual positive emotions and dyadic functioning. KE YWOR DS couple, emotions, dyadic adjustment, dyadic approach, self-help, well-being 1

INTRODUCTION

Couple therapy has seen growing interest among couples, clinicians, and researchers over the last several decades [START_REF] Gurman | The theory and practice of couple therapy: History, contemporary models, and a framework for comparative analysis[END_REF]. Gener-ally, the aim of this therapy is to correct dysfunctional communication and reinforce problem-solving skills, which become impaired in crisis contexts, and ensure marital success. Some of the most recent works have targeted the enhancement of coping [START_REF] Bodenmann | The couples coping enhance-ment training (CCET): A new approach to prevention of marital dis-tress based upon stress and coping[END_REF] or have emphasized the acceptance of partners' differences to resolve distress in couples [START_REF] Dimidjian | Integrative behavioral couple therapy[END_REF]; for a review see [START_REF] Gurman | The theory and practice of couple therapy: History, contemporary models, and a framework for comparative analysis[END_REF].

Integrative and pragmatic by nature, these therapeutic interventions emphasize the couple's resources, but the dysfunctions remain the target. Well-being as a primary target for couple interventions, on the basis of the positive psychology approach, remains an understudied field of research [START_REF] Kauffman | Finding and fostering the positive in relationships: Positive interventions in couples therapy[END_REF]. This lack of research is surprising considering the significant impact of well-being-based positive psychology interven-tions at the individual level [START_REF] Bolier | Positive psychology interventions: A meta-analysis of randomized controlled studies[END_REF].

1.1

Dysfunction and distress, a usual target for couple therapies Couple distress has become a major focus in recent decades, with a large body of research highlighting the factors and processes that could promote or impair a healthy romantic relationship [START_REF] Lebow | Research on the treatment of couple distress[END_REF]. Several types of interven-tions targeting impaired dyadic interactions, negative communication patterns, and marital dissatisfaction have been deployed. Some inter-ventions have adopted a preventive basis of couple distress (e.g., on the basis of stress and coping, Bodenmann, Hilpert, Nussbeck, & Brad-bury, 2014;[START_REF] Bodenmann | The couples coping enhance-ment training (CCET): A new approach to prevention of marital dis-tress based upon stress and coping[END_REF], or on the basis of imago relationship therapy, [START_REF] Schmidt | Evaluating the impact of the "getting the love you want" couples workshop on relational satisfaction and communication patterns[END_REF], and others have adopted a remediation basis of couple distress (e.g., behaviourally based couple therapy, [START_REF] Baucom | Behaviorally-based couple therapies reduce emo-tional arousal during couple conflict[END_REF], integrative behavioural cou-ple therapy, [START_REF] Christensen | Integrative behavioral couple ther-apy[END_REF], or emotion-focused therapy, [START_REF] Johnson | Creating connection: The practice of emotionally focused marital therapy[END_REF]; see [START_REF] Lebow | Research on the treatment of couple distress[END_REF] for a review). Whereas couple distress appeared as the main target of several couple interventions, for couples beyond the threshold of distressed relationships, a shift towards well-being promotion would be of interest, especially because some fields of research in psychology consider and support well-being as their primary goal.

Well-being matters in couple life

Subjective well-being is represented by the combination of satisfac-tion with life (the cognitive component), a low frequency of experiencing negative affectivity, and a high frequency of experiencing positive affectivity (the affective component; [START_REF] Diener | Subjective well-being: The science of happiness and a proposal for a national index[END_REF][START_REF] Lucas | Subjective well-being[END_REF]. Positive emotions are important because they activate an urge to explore, to be creative, to be kind, and to create social connections-in short, they broaden one's thought and action repertoire (Broaden-andbuild model;[START_REF] Fredrickson | The role of positive emotions in positive psychol-ogy: The broaden-and-build theory of positive emotions[END_REF]. In this way, numerous resources can be built and stored (e.g., knowledge and skills, sense of oneself, optimism, and social bonds) and may even cre-ate an upward spiral towards more fulfilling positive emotions [START_REF] Fredrickson | Positive emotions broaden and build[END_REF]. Thus, by experiencing positive emotions, one can access a world of opportunities, including enduring congruent social bonds [START_REF] Fredrickson | Positive emotions broaden and build[END_REF].

Well-being and positive emotions represent fundamental resources of human beings [START_REF] Fredrickson | Positive emotions broaden and build[END_REF][START_REF] Hilpert | Improving personal happiness through couple intervention: A random-ized controlled trial of a self-directed couple enhancement program[END_REF]. They are more than a protective factor for individual mental health [START_REF] Kobau | Mental health promotion in public health: Perspectives and strategies from positive psychology[END_REF][START_REF] Layous | Positive activities as protective factors against mental health conditions[END_REF], as they also appear to have several positive effects on general health and social aspects, such as relationships and support [START_REF] Chida | Positive psychological well-being and mor-tality: A quantitative review of prospective observational studies[END_REF][START_REF] Lyubomirsky | The benefits of frequent pos-itive affect: Does happiness Lead to success[END_REF][START_REF] Steptoe | Positive affect and psychobiological processes relevant to health[END_REF][START_REF] Steptoe | Positive affect and health-related neuroendocrine, cardiovascular, and inflammatory processes[END_REF]. Happy people, or people who frequently experience positive affect, tend to experience more satisfying interpersonal relationships, especially committed romantic ones, and to possess more social and conflict resolution skills [START_REF] Hilpert | Improving personal happiness through couple intervention: A random-ized controlled trial of a self-directed couple enhancement program[END_REF][START_REF] Lyubomirsky | The benefits of frequent pos-itive affect: Does happiness Lead to success[END_REF][START_REF] Myers | The funds, friends, and faith of happy people[END_REF]. The promotion of health and well-being (e.g., life satisfaction and momentary happiness) has been found to benefit from satisfying romantic bonds and conjugal quality [START_REF] Carr | Happy marriage, happy life? Marital quality and subjective well-being in later life[END_REF][START_REF] Headey | Top-down versus bottom-up theories of subjective well-being[END_REF][START_REF] Kiecolt-Glaser | Lovesick: How couples' rela-tionships influence health[END_REF][START_REF] Robles | Marital quality and health: A meta-analytic review[END_REF]. High con-jugal quality involves satisfaction with the relationship, positive atti-tudes towards the partner, and few hostile and negative behaviours [START_REF] Robles | Marital quality and health: A meta-analytic review[END_REF]). People's sense of feeling understood, cared for, and validated by their partners, otherwise called perceived partner responsiveness, is a significant predictor of health (Kiecolt-Glaser & Wil-son, 2017). Furthermore, social sharing of emotions between romantic partners deepens and is likely to enhance an upward spiral of positive interactions within the relationship, which can be nurtured by positive emotions and savouring [START_REF] Camgoz | The role of savoring in work-family conflict[END_REF][START_REF] Gable | Good news! Capitalizing on positive events in an interpersonal context[END_REF]. The qual-ity of the relationship with the intimate partner seems to be a key fac-tor in the enhancement and maintenance of happiness at the individual level [START_REF] Hilpert | Improving personal happiness through couple intervention: A random-ized controlled trial of a self-directed couple enhancement program[END_REF]. Married people seem more likely than others to display full life aspects, that is, a life filled with meaning, pleasure, and engagement, with significant levels of life satisfaction and positive emotions (Peterson, Park, & Seligman, 2005). Finally, marital adjustment and life satisfaction bidirectionally influence each other [START_REF] Be | Prospective associa-tions between marital adjustment and life satisfaction: Marital adjust-ment and life satisfaction[END_REF].

Couple positive psychology intervention

The positive psychology field suggests that intentional activities influ-ence well-being at the individual level and increase happiness with lasting changes [START_REF] Bolier | Positive psychology interventions: A meta-analysis of randomized controlled studies[END_REF][START_REF] Donaldson | Happiness, excellence, and optimal human functioning revisited: Examining the peer-reviewed literature linked to positive psychology[END_REF][START_REF] Mitchell | Positive psychology and the internet: A mental health opportunity[END_REF][START_REF] Seligman | Positive psy-chology progress: Empirical validation of interventions[END_REF][START_REF] Sin | Enhancing well-being and alleviating depressive symptoms with positive psychology interventions: A practice-friendly meta-analysis[END_REF]. Positive social bonds are fundamental for the growth of personal happiness (Reis & Gable, 2003), and happiness can become a dyadic quest [START_REF] Hilpert | Improving personal happiness through couple intervention: A random-ized controlled trial of a self-directed couple enhancement program[END_REF] for specific activities that promote couples' positive attributes (e.g., [START_REF] Algoe | Positive psychology in context: Effects of expressing gratitude in ongoing relationships depend on percep-tions of enactor responsiveness[END_REF][START_REF] Coulter | Effects of an intervention designed to enhance romantic relationship excitement: A randomized-control trial[END_REF].

There are already a few couple interventions on the basis of the positive psychology approach. For example, one study examined the injection of gratitude into romantic relationships and underlined that it promoted positive emotions [START_REF] Algoe | Positive psychology in context: Effects of expressing gratitude in ongoing relationships depend on percep-tions of enactor responsiveness[END_REF]. Moreover, when partners were perceived as being particularly responsive when expressing gratitude, improvements in daily subjective well-being were found-such as decreases in negative emotions and improve-ments in satisfaction with life and positive emotions [START_REF] Algoe | Positive psychology in context: Effects of expressing gratitude in ongoing relationships depend on percep-tions of enactor responsiveness[END_REF]. Furthermore, if one partner experienced gratitude, relational growth was nurtured by an upward spiral for each partner in the relationship, adding adaptive value for both partners, as suggested by the find-remind-and-bind theory [START_REF] Algoe | Find, remind, and bind: The functions of gratitude in everyday relationships: Gratitude in relationships[END_REF][START_REF] Algoe | Positive psychology in context: Effects of expressing gratitude in ongoing relationships depend on percep-tions of enactor responsiveness[END_REF]. Another intervention intended to enhance committedrelationship excitement, with activities practiced for 90 min a week, also led to positive affectivity and relationship satisfaction, with follow-up data showing effect maintenance [START_REF] Coulter | Effects of an intervention designed to enhance romantic relationship excitement: A randomized-control trial[END_REF].

In another study, training on the basis of active-constructive responses (i.e., enthusiastic and supportive responses to the partner's good news) created a positive impact with successful capitalization (i.e., social sharing of positive experiences) of positive events by the partner [START_REF] Gable | What do you do when things go right? The intrapersonal and interpersonal benefits of sharing positive events[END_REF][START_REF] Woods | I'm so excited for you!" How an enthusiastic responding intervention enhances close relationships[END_REF]. This training also led to improvements in rela-tionship well-being, especially in the perceived relationship satisfac-tion of the partners and the receipt of gratitude [START_REF] Woods | I'm so excited for you!" How an enthusiastic responding intervention enhances close relationships[END_REF].

It is noticeable that these existing couple positive psychology interventions (CPPIs) are singlecomponent interventions. This struc-ture is rather surprising given that multicomponent interventions may be more effective than single-component interventions [START_REF] Sin | Enhancing well-being and alleviating depressive symptoms with positive psychology interventions: A practice-friendly meta-analysis[END_REF]. Moreover, multicomponent interventions could allow participants to find activities that are consistent with their own aspirations, as defined in the self-concordance motivation model [START_REF] Sheldon | Goal striving, need satisfaction, and longitudinal well-being: The self-concordance model[END_REF][START_REF] Sheldon | Achieving sustainable gains in happiness: Change your actions, not your circumstances*[END_REF] and the person-activity fit model [START_REF] Lyubomirsky | How do simple positive activities increase well-being?[END_REF][START_REF] Schueller | The science of self-help: Translating positive psychology research into increased individual happiness[END_REF]. Moreover, because the longest interventions show bet-ter outcomes than shorter ones [START_REF] Sin | Enhancing well-being and alleviating depressive symptoms with positive psychology interventions: A practice-friendly meta-analysis[END_REF], we chose to conduct a 4-week intervention. Therefore, the current study intro-duces a multicomponent intervention addressing couples wishing to improve their well-being.

Couple+: A new CPPI

Cultivating well-being and strengths within a dyadic approach repre-sents a meaningful and promising preventive step in addressing con-flicts that occur in daily life and promoting relationship quality and stability [START_REF] Bradford | It takes two? An explora-tion of processes and outcomes in a two-session couple intervention[END_REF]. Many couples seek novel alternatives to obtain advice or assistance rather than more typical clinical sessions [START_REF] Doss | Mari-tal therapy, retreats, and books: The who, what, when, and why of relationship help-seeking[END_REF], where engagement and retention can be a challenge [START_REF] Lebow | Research on the treatment of couple distress[END_REF]. Couple+ intervention was designed as an easily accessible self-help programme. This type of CPPI was meant to overcome noticeable drawbacks of one-to-one interventions (e.g., dissemination, financial and time costs, and organization for childcare; [START_REF] Bradford | It takes two? An explora-tion of processes and outcomes in a two-session couple intervention[END_REF][START_REF] Halford | Best practice in couple relationship education[END_REF]Halford, Markman, & Stan-ley, 2008). Moreover, because a variety of interventions have previ-ously been found to provide benefits, this CPPI was innovatively based on a multicomponent approach [START_REF] Parks | Putting positive psychology into practice via self-help[END_REF][START_REF] Thompson | Gender differences in the person-activity fit for positive psychology interventions[END_REF]. This theory-driven preventive CPPI was based on [START_REF] Kauffman | Finding and fostering the positive in relationships: Positive interventions in couples therapy[END_REF] assumption that CPPIs are feasible and of interest for encouraging romantic relationship development, maintenance, and functioning. Couple+ intervention followed the [START_REF] Seligman | Flourish: A visionary new understanding of happiness and well-being[END_REF] interventional model, which identifies five major components that cul-tivate well-being: positive emotions, engagement in life (global involvement in one's commitments), meaning (developing the belief that one belongs to something larger than oneself), accomplishments (achieving something for its own sake), and positive relationships. This intervention was not designed for distressed couples but rather to address autonomous couples with a good initial level of functioning who, nonetheless, wished to improve it. Couple+ offered a way to nurture positive emotions, strengths, and attuned communi-cation patterns within the couple through intentional daily activities for 4 weeks. The aim was to cultivate resources that might improve the quality and stability of couples' romance and to prevent any issues from arising [START_REF] Atkinson | Mindfulness training and the cultivation of secure, satisfying couple relationships[END_REF][START_REF] Bradford | It takes two? An explora-tion of processes and outcomes in a two-session couple intervention[END_REF]. Therefore, this pilot CPPI targeted several constructs that have been found to nur-ture a healthy and flourishing intimate relationship (i.e., "positive rela-tionships"): individual satisfaction, shared moments, kindness and gratitude (i.e., "positive emotions"), active and constructive communi-cation (i.e., "meaning"), and identification and use of the partners' and the couple's strengths (i.e., "engagement"; [START_REF] Fincham | Of memes and marriage: Toward a positive relationship science[END_REF][START_REF] Moore | What is "healthy marriage"?: Defining the concept[END_REF][START_REF] Seligman | Flourish: A visionary new understanding of happiness and well-being[END_REF], with a weekly touch of mindful-ness to cultivate the relationship [START_REF] Atkinson | Mindfulness training and the cultivation of secure, satisfying couple relationships[END_REF]. More information about Couple+ is available in Table 2.

Hypothesis

The study is a randomized control trial including couples who have no major dysfunctions separated into two groups: an intervention group and a control group on the waiting list.

Hypothesis 1 On the basis of assumptions by [START_REF] Algoe | Positive psychology in context: Effects of expressing gratitude in ongoing relationships depend on percep-tions of enactor responsiveness[END_REF] and [START_REF] Coulter | Effects of an intervention designed to enhance romantic relationship excitement: A randomized-control trial[END_REF], we hypothesize that cou-ples in the intervention group will show benefits in subjective wellbeing compared with couples from the waiting list control (WLC) group. That is, we expect improvements in satisfaction with life and positive emotion and a decrease in negative emotion in couples from the intervention group compared with couples from the WLC group.

Hypothesis 2 As social sharing of emotions between romantic partners seems to deepen and enhance positive interactions within the relationship [START_REF] Camgoz | The role of savoring in work-family conflict[END_REF][START_REF] Gable | Good news! Capitalizing on positive events in an interpersonal context[END_REF], we expect that couples in the intervention group will show benefits in dyadic vari-ables such as communication pattern improvements and dyadic functioning compared with couples from the WLC group.

Hypothesis 3 Finally, we will explore whether the effects observed in the intervention group couples last beyond a 1-month follow-up. On the basis of assumptions by [START_REF] Coulter | Effects of an intervention designed to enhance romantic relationship excitement: A randomized-control trial[END_REF], we expect lasting changes in positive emotions in the intervention group couples.

METHOD

Participants

Ninety-eight individuals (a total of 49 heterosexual couples) were rec-ruited from the French population in 2015 by Lille University psychol-ogy students. The recruitment pool included students' social networks (i.e., relatives, online, or leisure networks). On the basis of the individ-uals' declarations, the exclusion criteria were Axis I disorders of the Diagnostic and Statistical Manual of Mental Disorders IV-TR, people receiving therapy, and deafness. To be included in the study, partici-pants had to be older than 18 years old and in a committed relation-ship for more than a year. No remuneration was provided. The participants' characteristics are displayed in Table 1. A flow diagram of the participants (Figure 1) represents each stage of the study.

Procedure

This study was approved by the Ethical Committee of the University of Lille Human and Social Sciences.

Information about the study was provided, and all the participants included in the study gave their writ-ten informed consent. Groups were balanced and controlled through a stratified randomization according to the participants' age and [START_REF] Atkinson | Mindfulness training and the cultivation of secure, satisfying couple relationships[END_REF] number of children. Baseline questionnaires were completed individu-ally and confidentially by the participants in the intervention and WLC groups at the same time. Then the intervention group participants began the 4-week CPPI, which was mailed to them with detailed instructions and the investigators' contact details. Post-test question-naires were completed immediately at the end of the CPPI. The WLC group participants completed the same questionnaires. The interven-tion group participants were invited to complete a follow-up ques-tionnaire 1 month later.

PPI overview

This programme stemmed from a literature review of PPIs that was adapted for couples from a French population. Every participant received an activity diary that could be completed individually. The activities were mostly conceived as dyadic, but some were individual activities. Individual activities could be similar or complementary for the two partners (i.e., if one exercise of the day invited one member of the dyad to share a good event with his or her partner, then the partner was invited to learn how to respond in a constructive and active way). The activities depended on mutual openness and self-awareness. They were intended to take less than 20 min per day. The participants were invited to engage nonjudgementally with each other during the course of the activities. The content for each week of the CPPI for couples is illustrated in Table 2.

2.4

Measures Questionnaires were always administered in the same order across groups and times. The intervention group couples received three mea-surement times: pretest, post-test, and follow-up at 1 month, whereas the WLC group received two measurement times: pretest and post-test. The WLC group couples received access to the Couple+ after completing the immediate post-test questionnaire.

Sociodemographic variables

A questionnaire allowed us to collect information about the partici-pants' age, sex, family, education, and professional status.

Satisfaction with Life Scale

This 5-item scale evaluated the respondents' overall satisfaction with life on a 7-point scale ranging from 1 (strongly disagree) to 7 (strongly agree). The overall scores varied from 5 to 35 [START_REF] Diener | The Satisfac-tion With Life Scale[END_REF]. Cronbach's alpha in the French student popu-lation and elderly individuals was .80 and .84, respectively (French version by [START_REF] Blais | L'échelle de satisfaction de vie: Validation canadiennefrançaise du "satisfaction with life scale[END_REF], and .87 in the current study.

Emotional Valence Measure

This scale, on the basis of the Diener model of subjective well-being [START_REF] Diener | The personality structure of affect[END_REF], included 23 items representing 23 emotions. Respondents indicated the frequency they experienced each emotion on a 7-point scale from never to several times a day. Two second-order factors identified positive or negative valence. The internal consistencies established among French health care professionals were .92 and .81 for the negative and positive affectivity scales, respectively [START_REF] Antoine | Évaluer le bien-être subjectif: La place des émotions dans les psychothérapies positives [Measuring subjective well-being: Place of the emotions in positive psychotherapies[END_REF], and were .91 and .88, respectively, in the current study.

Communication Patterns Questionnaire

This scale addressed the interaction strategies a couple used when conflict arose in the relationship, during relationship issues, and after a discussion of a relationship issue using 35 items rated on a 9point scale ranging from not at all to a lot. Four factors were represented: coercion (with notions of blame, threat, physical, and verbal aggres-sion), mutuality (highlighting mutual discussion, understanding, and lack of avoidance), destructive process (patterns of demand-with-drawal, pressure-resist, and criticize-defend) and post-conflict dis-tress (guilt, feeling hurt, and withdrawal from the situation; [START_REF] Noller | The validity of the communication patterns questionnaire[END_REF]. On the basis of [START_REF] Christensen | Dysfunctional interaction patterns in couples[END_REF] instrument, Noller and White (1990) validated a 4-factor model with internal consisten-cies of .86, .88, .79, and .73, respectively. [START_REF] Lecocq | Attitude face aux conflits et ajustement dyadique: Validité du « Communication Pattern Questionnaire » [Atti-tude to conflict and dyadic adjustment: Validity of the "Communica-tion Pattern Questionnaire[END_REF] validated a French version with a total internal consistency of .72. In this study, internal consistencies were .75 for mutuality, .75 for coer-cion, .73 for post-conflict distress, and .84 for destructive process. The overall scale's internal consistency was .84.

Dyadic Adjustment Scale

The Dyadic Adjustment Scale (DAS)-16 is a French adaptation and factorial revision [START_REF] Antoine | Échelle d'ajustement dyadique: Intérêts cliniques d'une révision et validation d'une version abrégée [Dyadic adjustment scale: Clinical interests of a revision and validation of an abbreviated version[END_REF] of the DAS [START_REF] Spanier | Measuring dyadic adjustment: New scales for assessing the quality of marriage and similar dyads[END_REF]. This revised scale assessed two dimensions, the degree of agreement in a couple and the quality of the dyadic interac-tions, which were represented by 16 items in the French version. An overall score reflected the quality of the dyadic adjustment. Answers were given on 6-point Likert scales. First, the respondents were asked about their degree of agreement with each other in several domains (from never agree to always agree). Second, they indicated to what extent the items matched their current experience (from never to always). Finally, they shared their degree of happiness within the rela-tionship (from extremely unhappy to extremely happy). The validation of the DAS-16 found internal consistencies of .89 and .75 for the degree of agreement and quality of interactions dimensions, respec-tively [START_REF] Antoine | Échelle d'ajustement dyadique: Intérêts cliniques d'une révision et validation d'une version abrégée [Dyadic adjustment scale: Clinical interests of a revision and validation of an abbreviated version[END_REF]. In this study, internal consistency of .78 was found for degree of agreement, .72 for quality of dyadic interaction, and .82 for dyadic adjustment.

Compliance with the intervention

Compliance with the intervention measures allowed us to note the number of positive psychology activities completed during the CPPI. Compliance was measured on a self-report sheet that was returned along with the immediate post-test questionnaires.

Statistical analyses

Statistical analyses were conducted with Jamovi 0.8.6.0 for Windows. Chi-squared and between-group t-test baseline analyses were used to assess baseline and sociodemographic variables between the two groups. Mann-Whitney analyses were used to perform attrition anal-ysis due to the small sample size and to the violation of the normality assumption. The data were analysed using a linear mixed model, allowing us to study the hierarchical structure of the data and interactions [START_REF] Faraway | Extending the linear model with R: Generalized linear, mixed effects and nonparametric regression models[END_REF]. Longitudinal couple data are nested because repeated measures are nested within a person and persons are nested within cou-ples, which are then nested within an intervention. The linear mixed model provides an analysis and description of the variables that change with time by couple controlling for subject influence. Repeated-measure analyses of variance were conducted to study changes in the intervention group at the three measurement times (pretest, immediate post-test, and follow-up). We were therefore able to obtain information about the main effect of time in the intervention group. Bonferroni post hoc tests were conducted for significant out-comes to capture the pairwise significance testing. Cohen's d was used to assess Bonferroni post hoc test effect sizes. The Bonferroni post hoc test was selected because of its robustness, even when the sphericity assumption was violated (Field, 2009, p. 472). The assump-tion of sphericity was tested with Mauchly's test.

RESULTS

Path of participants

This CPPI appeared acceptable and feasible for couples who could implement it in their daily life. The intervention group participants completed 92.2% of the CPPI on average (SD = 9.0), ranging from 70.4% to 100%.

The flow diagram (Figure 1) displays participants' attrition and provides associated reasons.

In the intervention group, attrition rates were 12.5% at the imme-diate post-test and 35.4% at follow-up, whereas in the WLC group, the attrition rate was 28% at the immediate post-test. Analyses rev-ealed several differences in demographic variables and the pretest questionnaires between the nine persons from the intervention group who did not return the follow-up questionnaires (subgroup NC) and the participants who returned them (subgroup C). Significant differ-ences were noted between the two subgroups in the type of activity (χ2 [1] = 7.662, p = .022), with more students and employed partici-pants in subgroup C than in subgroup NC. Differences were also found for baseline satisfaction with life (higher level in subgroup C

Preliminary analyses

Equivalency between the groups at pretest was assessed with chi-square and between-group t-tests. The analyses identified no differ-ences, except in terms of years of schooling. The intervention group participants had studied significantly more years after primary school (M = 9.07, SD = 3.4) than the WLC group participants (M = 7.27, SD = 3.4, t [74] = 2.248, and p = .02).

Main analyses

The efficacy of the intervention was studied with linear mixed model analyses, and pretest scores were controlled to do so. The differences between subjects and couples were controlled for each variable before and after the intervention. The group and time interactions are shown in Table 3.

Hypothesis 1 The hypothesis that couples in the intervention group would show benefits in subjective well-being compared with cou-ples from the WLC group was not entirely supported. The analyses showed improvements in positive emotions but not in satisfaction with life and a decrease in negative emotions in couples from the intervention group compared with couples from the WLC group. Hypothesis 2 The results only partially supported the hypothesis that couples in the intervention group would show benefits in commu-nication and dyadic variables. Indeed, analyses supported the fact that communication patterns of mutuality, quality of interaction, and dyadic adjustment improved in the intervention group com-pared with the WLC group. However, no group by time interac-tions was found for coercion, post-conflict distress, destructive process, and degree of agreement.

Hypothesis 3 The prediction that improvements in the intervention group would persist for 4 weeks after the end of the intervention was supported for quality of interaction and overall dyadic adjustment with moderate effect sizes (see Table 4 for the effect of time and Table 5 for Bonferroni post hoc comparison). The effects of time for positive emotions and mutuality were not confirmed by Bonferroni post hoc comparisons.

DISCUSSION

This randomized study examined the impact of a multicomponent, theory-driven, autonomous selfhelp CPPI on individual well-being and dyadic variables. Over this 4-week self-help intervention, the attrition level was 12.5% at an immediate post-test and 35.4% at follow-up. Individuals completed more than 70.4% of the activities. These elements thus underlined this intervention's feasibility, in line with [START_REF] Kauffman | Finding and fostering the positive in relationships: Positive interventions in couples therapy[END_REF] assumption. The current find-ing revealed that the implementation of intentional activities in cou-ples' daily lives produced immediate changes from the pretest to the post-test for some positive indicators (i.e., positive emotion, mutuality communication pattern, quality of interaction, and dyadic adjustment). The improvement in positive emotion was consistent with [START_REF] Coulter | Effects of an intervention designed to enhance romantic relationship excitement: A randomized-control trial[END_REF] 4-week single-component intervention and with [START_REF] Algoe | Positive psychology in context: Effects of expressing gratitude in ongoing relationships depend on percep-tions of enactor responsiveness[END_REF] 28-day single-component gratitude intervention. In the current study, couples in the intervention group showed improvements in dyadic variables (i.e., quality of interaction and dyadic adjustment) and in mutuality communication patterns over the course of the intervention compared with those in the control condition. Such observations are in line with the fact that social shar-ing of emotions between romantic partners, involving savouring and capitalization processes, may improve positive interactions within the couple [START_REF] Camgoz | The role of savoring in work-family conflict[END_REF][START_REF] Gable | Good news! Capitalizing on positive events in an interpersonal context[END_REF]. Moreover, the addition of a short weekly mindfulness practice might have added another tool to foster communication improvement [START_REF] Atkinson | Mindfulness training and the cultivation of secure, satisfying couple relationships[END_REF].

A deferred impact of the intervention was highlighted in the intervention group, from pretest to the 4-week follow-up for dyadic adjustment and quality of the interaction. This maintenance is in line with that of another type of activity encompassed by the CPPI, encouraging sharing, savouring, and capitalizing, which invited partici-pants to appreciate shared activities (i.e., create and schedule positive moments with my partner and how to respond in an active and con-structive way to my partner; [START_REF] Bryant | Understanding the pro-cesses that regulate positive emotional experience: Unsolved prob-lems and future directions for theory and research on savoring[END_REF]Cam-goz, 2014;[START_REF] Gable | Will you be there for me when things go right? Supportive responses to positive event dis-closures[END_REF][START_REF] Quoidbach | Posi-tive emotion regulation and well-being: Comparing the impact of eight savoring and dampening strategies[END_REF]. These CPPI activities aimed to expand the participants' focus on all aspects of their ongoing romantic relationship and to increase their positive interactions [START_REF] Kauffman | Finding and fostering the positive in relationships: Positive interventions in couples therapy[END_REF]. Immediate improvements in positive emotions from pretest to post-test test could have contributed to enriching the bounding resources developed over the course of the CPPI, as under-lined by its immediate effects on dyadic adjustment and mutuality pat-terns of communication.

In contrast to our assumption, we did not notice a decrease in negative emotion in couples in the intervention group compared with couples from the WLC group. We noticed no improvement in "negative" communication patterns such as coercion, post-conflict distress, and destructive processes. This finding can be explained by the fact that participants were coming from a community sample with no ini-tial major dyadic dysfunctions. It is also possible that Couple+, by emphasizing the development of positive interactions, could only act on this side and neglected to address the difficulties experienced at the individual or dyadic levels. Moreover, the limited duration may not have allowed the benefits on the positive side to have a cascading impact on the difficulties experienced. Regarding the maintenance of the effects at 1 month, the results did not show long-term improve-ments in positive emotion, in contrast to our assumption and [START_REF] Coulter | Effects of an intervention designed to enhance romantic relationship excitement: A randomized-control trial[END_REF] work. This result is surprising considering the current literature, including that on individual single-component inter-ventions such as Seligman et al.'s (2005) study from which some of the content of our intervention was adapted (i.e., acknowledge and share positive emotions with my partner, write and share a gratitude letter, and use character strengths). Indeed, Seligman et al. found that for these individual activities, effects were maintained at 1-month follow-up on a global happiness level. Several factors may explain these results.

The multicomponent nature of Couple+ may have resulted in a dilution of some of these effects and a loss of power. It would be interesting to compare the efficiency and indications of single-component versus multicomponent programmes. In addition, it is possible that the self-administered nature of the intervention was more conducive to the development of positive interactions than to the regulation of negative interactions, for which a programme admin-istered and mediated by a face-to-face therapist would be necessary. To address couples' distress, we recommend a group workshop facilitated by a therapist to strengthen the effectiveness of the programme and to use a single aspect to address specific issues. More broadly, we can question the relative power of these two types of interventions, particularly in couple therapy. This study had several limitations, such as its small sample size, which did not allow us to compute dyadic analysis, and the lack of screening for relationship issues before the intervention. The results should be interpreted with caution due to power-related issues. Dif-ferences between participants who did or did not fully complete the intervention by returning all the data may weigh in favour of system-atic attrition, which would limit the generalizability of the results of the current study. Indeed, participants who chose not to complete the intervention were less satisfied with their life, showed more coercion, more post-conflict distress, more destructive processes, and a lower degree of agreement than couples who completed the intervention. Conceived as a proof of concept and, therefore, conducted with a small sample, the data do not allow for more detailed analyses that would be necessary to identify the couples that benefited the most from the intervention or to identify the moderating factors of the intervention's impact. Moreover, this pilot study relied on participants' selfreports to assess the number of activities completed, and self-report measures are subject to social desirability bias. Another limita-tion is the lack of measurement of couple-enhancement activities attempted by the WLC group to determine the proportion of potential uncontrolled activities that might have affected the analyses and results. Instead of a WLC group, an active control group might have been more appropriate [START_REF] Algoe | Positive psychology in context: Effects of expressing gratitude in ongoing relationships depend on percep-tions of enactor responsiveness[END_REF]. Finally, a follow-up at 4 weeks for the WLC group participants would have been useful to compare both groups.

Overall, this pilot study suggests that injecting intentional dyadic activities into daily life for 4 weeks seems to present a promising approach for increasing positive emotions on a short-term basis and improving dyadic functioning. Future recruitment processes should ensure that the trial excludes couples who display relationship issues (e.g., ongoing affairs or interpersonal violence) and should select cou-ples with a longer shared life experience. To enhance the quality of the findings, a replication of this study with a larger sample appears crucial due to power-related implications. Moreover, the time course of the CPPI could be expanded (e.g., [START_REF] Antoine | Individual dif-ferences in the effects of a positive psychology intervention: Applied psychology[END_REF] and utilizing a design that would better allow us to understand the CPPI impact temporal entanglement. Future research might also look for specific patterns of change according to baseline characteristics to better adjust interventions to people's needs and expectations. For instance, according to [START_REF] Bryant | Understanding the pro-cesses that regulate positive emotional experience: Unsolved prob-lems and future directions for theory and research on savoring[END_REF], women may be prone to engage in more sharing with others and behavioural expression when encountering positive events than men. Moreover, as partners mutually influence each other, if one partner in the dyadic interaction changes his or her own behaviour due to specific tasks that create more change for her or him, it is likely that the dynamic system will shift and induce changes in the other partner [START_REF] Hilpert | Improving personal happiness through couple intervention: A random-ized controlled trial of a self-directed couple enhancement program[END_REF]. Finally, it is necessary to be cautious and not overly prone towards "positivity" within interventions designed for couples. A review established that positive valence does not always produce favourable outcomes depending on the context [START_REF] Mcnulty | Beyond positive psychology? Toward a contextual view of psychological processes and well-being[END_REF]. Additionally, a remediation intervention found that for a small portion of couples, excessively improving women's positive communi-cation skills could lead to a larger decline in relationship satisfaction across 5 years [START_REF] Baucom | Long-term prediction of marital quality following a relationship educa-tion program: Being positive in a constructive way[END_REF]. This finding highlights the fact that it is important to pay attention to the outcomes of such interventions and to take a differential approach [START_REF] Woodworth | Happy days: Positive psychology interventions effects on affect in an N-of-1 trial[END_REF]. Thus, all changes within the couple, even positive ones, could be a potential source of destabilization and readjustment. Future studies could also capture within-dyad information rather than focusing on the individual level [START_REF] Robles | Marital quality and health: A meta-analytic review[END_REF] and could explore actor-partner effects or the extent to which one partner's experience influences the other member of the dyadic relation [START_REF] Kenny | Dyadic data analysis[END_REF][START_REF] Kiecolt-Glaser | Lovesick: How couples' rela-tionships influence health[END_REF]. Furthermore, daily affec-tive processes could be explored in addition to perceived changes in relationship quality to obtain more insight into the longitudinal aspects and respective influences of one partner on the other [START_REF] Robles | Marital quality and health: A meta-analytic review[END_REF]. It also seems relevant to determine whether the effects are maintained over a longer follow-up. An optimistic perspective towards clinical practice is offered by this CPPI. This tool could be adapted according to couples' specific-ities and could be used by clinicians among community couples as a complementary approach in couple therapy sessions initially remedy-ing negative patterns.

  than NC; MC = 26.3, SDC = 5.3; MNC = 21.3, SDNC = 4.6; and U = 451.0, p = .016), coercion (lower level in subgroup C than NC; MC = 14.9, SDC = 7.9; MNC = 23.4, SDNC = 7.9; and U = 116.5, p = .002), post-conflict distress (lower level in subgroup C than NC; MC = 17.5, SDC = 8.0; MNC = 23.2, SDNC = 7.4; and U = 176.5, p = .04), destructive process (lower level in subgroup C than NC; MC = 25.2, SDC = 12.1; MNC = 40.7, SDNC = 11.3; and U = 112.5, p = .002), and degree of agreement (higher level in subgroup C than NC; MC = 48.6, SDC = 5.3; MNC = 45.2, SDNC = 3.3; and U = 443.5, p = .02).

TABLE 1

 1

	Participants' characteristics
	Variables	Value	WLC group (n = 36)	Intervention group (n = 40)
	Sex	Female (%)	18 (50)	20 (50)
	Age	Mean	39.8	37.5
		(range; SD)	(22-68; 13.9)	(21-80; 11.9)
	Years of schooling (after primary school)	Mean (range; SD)	7.27 (0-13; 3.46)	9.07 (2-20;3.48)
	Activity	Professional (%)	31 (86.1)	36 (90)
		Student (%)	1 (2.8)	2 (5)
		Retired (%)	3 (8.3)	0 (0)
		Unemployed (%)	1 (2.8)	2 (5)
	Marital status	Married (%)	20 (55.6)	24 (60)
		Civil union (%)	4 (11.1)	0 (0)
		Cohabitation (%)	12 (33.3)	16 (40)
	Couples have been together for… (years)	Mean (range; SD)	13.45 (3-38; 11.3)	13.26 (1.5-35;11.1)
	Lived together for… (years)	Mean (range; SD)	12.29 (2-38; 12.2)	10.61 (0.41-32;10.8)
	Number of children	Mean (range; SD)	1.25 (0-4; 1.3)	1.57 (0-7; 1.8)

-Draw my couple's current happiness pie chart (representing the overall couple's happiness level divided into as many portions as there are happy domains in the couple's life-the size of the portions indicates the time and energy allocated to each) -Draw my couple's desired happiness pie chart (representing the size that matches the couple's desires) -Implement minimal changes to get a step closer to our desired happiness pie chart Week 4 -Interplay with my partner's differences -Recognize and cultivate our strengths as a couple -Play a humorous game of couple's representation with metaphors -Select and show my partner five significant objects reflecting my thoughts when I contemplate future possibilities -Nurture my couple's strengths -Participate in a 10-min guided breathing mindfulness meditation

TABLE 4

 4 Intervention group change from pretest to follow-up (N = 31)

	Effect of time

TABLE 5

 5 Bonferroni post hoc comparisons

		Time		Mean difference	t	pbonf	Cohen's d
	Positive emotion	Pretest	Post-test	-1.871	-2.639	.039	-.47
			Follow-up	-1.000	-1.474	.453	-.26
		Post-test	Follow-up	0.871	1.342	.569	.24
	Mutuality	Pretest	Post-test	-3.097	-2.071	.141	-.37
			Follow-up	-4.032	-2.306	.085	-.41
		Post-test	Follow-up	-0.935	-0.746	1	-.13
	Quality of interaction	Pretest	Post-test	-0.581	-1.144	.785	-.20
			Follow-up	-1.548	-3.669	.003	-.65
		Post-test	Follow-up	-0.968	-2.125	.126	-.38
	Dyadic adjustment	Pretest	Post-test	-1.806	-2.049	.148	-.36
			Follow-up	-3.032	-3.676	.003	-.66
		Post-test	Follow-up	-1.226	-1.497	.434	-.26