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1. DA{\Phi}NE -2023/24 Activity report

Author

Milardi, C., Alesini, D., Behtouei, M., Bilanishvili, S., Bini, S., Boscolo, M., Buonomo, B., Cantarella, S., Ciarma, A., De Santis, A., Di Pasquale, E., Di Giulio, C., Di Pirro, G., Foggetta, L., Franzini, G., Gallo, A., Gargana, R., Incremona, S., Liedl, A., Michelotti, A., Piersanti, L., Quartullo, D., Ricci, R., Rotundo, U., Spampinati, S., Stecchi, A., Stella, A., Vannozzi, A., and Zobov, M.

Subjects
Physics - Accelerator Physics, Nuclear Experiment
Abstract

The DA{\Phi}NE operations during the last year have been devoted to deliver a statistically significant data sample to perform the first-ever measurement of kaonic deuterium X-ray transitions to the fundamental level. Operations for the SIDDHARTA-2 detector using a deuterium gas target started officially on the second half of May 2023, and have been organized in several runs here described., Comment: 7 pages, 3 figures, prepared for the INFN Laboratori Nazionali di Frascati 2023 activity report

Published
2024

2. Wakimoto construction for double loop algebras and $\zeta$-function regularisation

Author

Franzini, Tommaso

Subjects
Mathematical Physics, High Energy Physics - Theory, Mathematics - Quantum Algebra
Abstract

The Feigin-Frenkel homomorphism underpinning the Wakimoto construction realises an affine Lie algebra at critical level in terms of the $\beta\gamma$-system of free fields. It was recently shown that much of the construction also goes through for double loop algebras. However, certain divergent sums appear. In this paper, we show that, suggestively, these sums vanish when one performs $\zeta$-function regularisation., Comment: 29 pages

Published
2024

3. Hagedorn singularity in exact U_q(su(2)) S-matrix theories with arbitrary spins

Author

Ahn, Changrim, Franzini, Tommaso, and Ravanini, Francesco

Subjects
High Energy Physics - Theory
Abstract

Generalizing the quantum sine-Gordon and sausage models, we construct exact S-matrices for higher spin representations with quantum U_q(su(2)) symmetry, which satisfy unitarity, crossing-symmetry, and the Yang-Baxter equations with minimality assumption, i.e. without any unnecessary CDD factor. The deformation parameter q is related to a coupling constant. Based on these S-matrices, we derive the thermodynamic Bethe ansatz equations for q a root of unity in terms of a universal kernel where the nodes are connected by graphs of non-Dynkin type. We solve these equations numerically to find out Hagedorn-like singularities in the free energies at some critical scales and find a universality in the critical exponents, all near 0.5 for different values of the spin and the coupling constant., Comment: 28 pages, 9 figures; Rephrasing and additional comments and a reference added; To appear in Journal of High Energy Physics

Published
2024

10. An Introduction to Parametrically Excited Systems and Their Importance on the Dynamics of Slender Structures

Author

Franzini, Guilherme Rosa, Vernizzi, Guilherme Jorge, Abarbanel, Henry D. I., Series Editor, Braha, Dan, Series Editor, Érdi, Péter, Series Editor, Friston, Karl J., Series Editor, Grillner, Sten, Series Editor, Haken, Hermann, Series Editor, Jirsa, Viktor, Series Editor, Kacprzyk, Janusz, Series Editor, Kaneko, Kunihiko, Series Editor, Kelso, Scott, Founding Editor, Kirkilionis, Markus, Series Editor, Menezes, Ronaldo, Series Editor, Kurths, Jürgen, Series Editor, Nowak, Andrzej, Series Editor, Qudrat-Ullah, Hassan, Series Editor, Reichl, Linda, Series Editor, Schuster, Peter, Series Editor, Schweitzer, Frank, Series Editor, Sornette, Didier, Series Editor, Thurner, Stefan, Series Editor, Castilho Piqueira, José Roberto, editor, Nigro Mazzilli, Carlos Eduardo, editor, Pesce, Celso Pupo, editor, and Franzini, Guilherme Rosa, editor

Published
2024
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16. Hagedorn singularity in exact U q su 2 $$ {\mathcal{U}}_{\textrm{q}}\left({\mathfrak{su}}_2\right) $$ S-matrix theories with arbitrary spins

Author

Changrim Ahn, Tommaso Franzini, and Francesco Ravanini

Subjects
Integrable Field Theories, Nonperturbative Effects, Quantum Groups, Thermal Field Theory, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract Generalizing the quantum sine-Gordon and sausage models, we construct exact S-matrices for higher spin representations with quantum U q su 2 $$ {\mathcal{U}}_{\textrm{q}}\left({\mathfrak{su}}_2\right) $$ symmetry, which satisfy unitarity, crossing-symmetry and the Yang-Baxter equations with minimality assumption, i.e. without any unnecessary CDD factor. The deformation parameter q is related to a coupling constant. Based on these S-matrices, we derive the thermodynamic Bethe ansatz equations for q a root of unity in terms of a universal kernel where the nodes are connected by graphs of non-Dynkin type. We solve these equations numerically to find out Hagedorn-like singularity in the free energies at some critical scales and find a universality in the critical exponents, all near 0.5 for different values of the spin and the coupling constant.

Published
2024
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17. A dynamic model of intercultural competences and its implications in the field of international cooperation. Experience of Italian operators and cooperators abroad

Author

Manila Franzini

Subjects
interculturality, intercultural education, intercultural competences, functioning of competence, dynamic model, Education, Education (General), L7-991
Abstract

The study explores intercultural competences in the field of international cooperation. The substantive research question was whether Italian operators who have gained experience abroad, think they have developed intercultural competences and what competences they think they possess. This study involved a total of 20 representatives of Non-Governmental Organisations (NGOs) from Lombardy (Italy), 16 operators working for NGOs in developing countries and 10 Italian international professionals from the UNDP and WHO agencies based in Geneva (Switzerland). In this empirical research project, a semi-structured interview was administered to NGO leaders, a questionnaire to NGO co-operators and UN international operators and a narrative interview to the latter. Qualitative methods of textual analysis were used. The author has created a dynamic model of intercultural competences consisting of fifteen recurrent competences. In this article, the author presents her model and how to assess intercultural competences. The empirical study involving professionals of Italian nationality. The topic of intercultural competences raises a substantial question about their deep, inner workings in the individual. Key issues for future developments in intercultural competences training are made explicit.

Published
2024
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19. Design, optimization and experimental characterization of RF injectors for high brightness electron beams and plasma acceleration

Author

Shpakov, V., Alesini, D., Anania, M. P., Behtouei, M., Buonomo, B., Bellaveglia, M., Biagioni, A., Cardelli, F., Carillo, M., Chiadroni, E., Cianchi, A., Costa, G., Del Giorno, M., Faillace, L., Ferrario, M., del Franco, M., Franzini, G., Galletti, M., Giannessi, L., Giribono, A., Liedl, A., Lollo, V., Mostacci, A., Di Pirro, G., Piersanti, L., Pompili, R., Di Raddo, G., Romeo, S., Silvi, G., Stella, A., Vaccarezza, C., Villa, F., and Vannozzi, A.

Subjects
Physics - Accelerator Physics, Physics - Instrumentation and Detectors
Abstract

In this article, we share our experience related to the new photo-injector commissioning at the SPARC\_LAB test facility. The new photo-injector was installed into an existing machine and our goal was not only to improve the final beam parameters themselves but to improve the machine handling in day-to-day operations as well. Thus, besides the pure beam characterization, this article contains information about the improvements, that were introduced into the new photo-injector design from the machine maintenance point of view, and the benefits, that we gained by using the new technique to assemble the gun itself.

Published
2022
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24. Plasma Transthyretin and Its Ligands

Author

Franzini, Maria, Sanguinetti, Chiara, Musetti, Veronica, Castiglione, Vincenzo, Aimo, Alberto, Vergaro, Giuseppe, Emdin, Michele, Emdin, Michele, editor, Vergaro, Giuseppe, editor, Aimo, Alberto, editor, and Fontana, Marianna, editor

Published
2024
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30. Quartic Hamiltonians, and higher Hamiltonians at next-to-leading order, for the affine $\mathfrak{sl}_2$ Gaudin model

Author

Franzini, Tommaso and Young, Charles A. S.

Subjects
Mathematics - Quantum Algebra, High Energy Physics - Theory
Abstract

In this work we will use a general procedure to construct higher local Hamiltonians for the affine $\mathfrak{sl}_2$ Gaudin model. We focus on the first non-trivial example, the quartic Hamiltonians. We show by direct calculation that the quartic Hamiltonians commute amongst themselves and with the quadratic Hamiltonians which define the model. We go on to introduce a certain next-to-leading-order semi-classical limit of the model. In this limit, we are able to write down the full hierarchy of higher local Hamiltonians and prove that they commute., Comment: 32 pages,1 figure. Accepted version for J. Phys. A: Math. Theor

Published
2022
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31. Relationships between enabling services use and access to care among adults with cardiometabolic risk factors: findings from the 2014 National Health Center Patient Survey

Author

Martinez, G Sofia, White, Kellee, Yue, Dahai, Franzini, Luisa, Fryer, Craig S, Sinaii, Ninet, and Roby, Dylan H

Subjects
Health Services and Systems, Public Health, Health Sciences, Health Services, Prevention, Behavioral and Social Science, Clinical Research, Management of diseases and conditions, 8.1 Organisation and delivery of services, Health and social care services research, 7.1 Individual care needs, Generic health relevance, Good Health and Well Being, Adult, Cardiovascular Diseases, Community Health Centers, Health Services Accessibility, Health Surveys, Humans, Middle Aged, Poverty, United States, Enabling services, Cardiometabolic risk factors, Community health centers, Delayed care, Emergency room visits, Library and Information Studies, Nursing, Public Health and Health Services, Health Policy & Services, Health services and systems, Public health
Abstract

BackgroundCommunity health centers (CHCs) provide comprehensive primary and preventive care to medically underserved, low-income, and racially/ethnically diverse populations. CHCs also offer enabling services, non-clinical assistance to reduce barriers to healthcare due to unmet social and material needs, to improve access to healthcare and reduce health disparities. For patients with modifiable cardiometabolic risk factors, including obesity, hypertension, and diabetes, enabling services may provide additional support to improve disease management. However, little is known about the relationship between enabling services and healthcare accessibility and utilization among patients with cardiometabolic risk factors.MethodsThis study uses data from the 2014 Health Center Patient Survey to examine the relationship between enabling services use and delayed/foregone care, routine check-ups, and emergency room visits, among adult community health center patients in the United States with cardiometabolic risk factors (N = 2358). Outcomes of enabling services users were compared to nonusers using doubly robust propensity score matching methods and generalized linear regression models.ResultsOverall, enabling service users were 15.4 percentage points less likely to report delayed/foregone care and 29.4 percentage points more likely to report routine check-ups than nonusers. Enabling service users who lived in urban areas, younger and middle-aged adults, and those with two cardiometabolic risk factors were also less likely to report delayed/foregone care and/or more likely to report routine check-ups in comparison with nonusers. However, among adults with three or more cardiometabolic risk factors, enabling services use was associated with a 41.3 percentage point increase in emergency room visits and a 7.6 percentage point decrease in routine check-ups.ConclusionsThe findings highlight the value in utilizing enabling services to improve timeliness and receipt of care among CHC patients with heightened cardiometabolic risk. There is a need for targeting high-risk populations with additional enabling services to support management of multiple chronic conditions.

Published
2022

33. Matthew Lipman and Ann Margaret Sharp: Philosophy for Children's Educational Revolution. SpringerBriefs in Education

Author

Roberto Franzini Tibaldeo and Roberto Franzini Tibaldeo

Abstract

This book explores the contribution to education contained in the theoretical work and teaching practice of Matthew Lipman (1923-2010) and Ann Margaret Sharp (1942-2010). Their long-lasting cooperation gave rise to the well-known "Philosophy for Children" (P4C) curriculum, which is nowadays globally widespread. P4C basically relies on the following innovations: firstly, the unprecedented connection between philosophy and childhood; secondly, the reframing of philosophy in practical, viz., not reductively theoretical terms; thirdly, the employment of philosophy to foster democracy and moral capabilities through the development of children's thoughtfulness and autonomous thinking, which would eventually result in empowering children's social abilities and increasing their self-defence against consumerism, propaganda, and manipulation; finally, the stand against a strictly cognitivist approach to education. More than just contextualizing these innovations in the coeval historical and social context, the author shows that P4C's revolutionary stance on education relies on the fruitfulness of Lipman and Sharp's intellectual cooperation and on their manifold abilities as researchers, teachers, trainers, communicators, motivators, and community-builders. The book analyzes their philosophical-educational vision and the scholastic curriculum they developed jointly; additionally, it provides a critical appraisal of P4C's achievements as well as of its future perspectives.

Published
2023
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36. Pure cut vs. Endocut in endoscopic biliary sphincterotomy: Systematic review and meta-analysis of randomized clinical trials

Author

Luiza Bicudo de Oliveira, Mateus Pereira Funari, Angelo So Taa Kum, Alexandre de Moraes Bestetti, Vitor Ottoboni Brunaldi, Tomazo Antonio Prince Franzini, Eduardo Turiani Hourneaux Moura, Luiza Martins Baroni, Matheus Ferreira de Carvalho, Wanderley Marques Bernardo, and Eduardo Guimarães Hourneaux de Moura

Subjects
Pancreatobiliary (ERCP/PTCD), ERC topics, Stones, Diseases of the digestive system. Gastroenterology, RC799-869
Published
2024
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41. Heart rate variability and stroke or systemic embolism in patients with atrial fibrillation

Author

Aeschbacher, Stefanie, Bhend, Katalin, Blum, Steffen, Bonati, Leo H., Carmine, Désirée, Conen, David, Eken, Ceylan, Fischer, Urs, Girroy, Corinne, Hennings, Elisa, Krisai, Philipp, Kühne, Michael, Mäder, Nina, Meyer-Zürn, Christine, Meyre, Pascal B., Monsch, Andreas U., Mosher, Luke, Müller, Christian, Osswald, Stefan, Paladini, Rebecca E., Peter, Raffaele, Schweigler, Adrian, Sticherling, Christian, Szucs, Thomas, Völlmin, Gian, Aujesky, Drahomir, Fuhrer, Juerg, Roten, Laurent, Jung, Simon, Mattle, Heinrich, Netzer, Seraina, Adam, Luise, Aubert, Carole Elodie, Feller, Martin, Loewe, Axel, Moutzouri, Elisavet, Schneider, Claudio, Flückiger, Tanja, Groen, Cindy, Ehrsam, Lukas, Hellrigl, Sven, Nuoffer, Alexandra, Rakovic, Damiana, Schwab, Nathalie, Wenger, Rylana, Zarrabi Saffari, Tu Hanh, Rodondi, Nicolas, Reichlin, Tobias, Beynon, Christopher, Dillier, Roger, Deubelbeiss, Michèle, Eberli, Franz, Franzini, Christine, Juchli, Isabel, Liedtke, Claudia, Murugiah, Samira, Nadler, Jacqueline, Obst, Thayze, Roth, Jasmin, Schlomowitsch, Fiona, Schneider, Xiaoye, Studerus, Katrin, Tynan, Noreen, Weishaupt, Dominik, Müller, Andreas, Friedli, Corinne, Kuest, Silke, Scheuch, Karin, Hischier, Denise, Bonetti, Nicole, Grau, Alexandra, Villinger, Jonas, Laube, Eva, Baumgartner, Philipp, Filipovic, Mark, Frick, Marcel, Montrasio, Giulia, Leuenberger, Stefanie, Rutz, Franziska, Beer, Jürg-Hans, Auricchio, Angelo, Anesini, Adriana, Camporini, Cristina, Caputo, Maria Luce, Peronaci, Rebecca, Regoli, Francois, Ronchi, Martina, Conte, Giulio, Brenner, Roman, Altmann, David, Fink, Karin, Gemperle, Michaela, Ammann, Peter, Firmann, Mathieu, Foucras, Sandrine, Rime, Martine, Hayoz, Daniel, Berte, Benjamin, Bühler, Kathrin, Justi, Virgina, Kellner-Weldon, Frauke, Koch, Melanie, Mehmann, Brigitta, Meier, Sonja, Roth, Myriam, Ruckli-Kaeppeli, Andrea, Russi, Ian, Schmidt, Kai, Young, Mabelle, Kobza, Richard, Rigamonti, Elia, Cereda, Carlo, Cianfoni, Alessandro, De Perna, Maria Luisa, Frangi-Kultalahti, Jane, Mayer Melchiorre, Patrizia Assunta, Pin, Anica, Terrot, Tatiana, Vicari, Luisa, Moschovitis, Giorgio, Ehret, Georg, Gallet, Hervé, Guillermet, Elise, Lazeyras, Francois, Lovblad, Karl-Olof, Perret, Patrick, Tavel, Philippe, Teres, Cheryl, Shah, Dipen, Lauriers, Nathalie, Méan, Marie, Salzmann, Sandrine, Schläpfer, Jürg, Porretta, Alessandra Pia, Grêt, Andrea, Novak, Jan, Vitelli, Sandra, Stephan, Frank-Peter, Gallino, Augusto, Di Valentino, Marcello, Aebersold, Helena, Foster, Fabienne, Schwenkglenks, Matthias, Düring, Marco, Sinnecker, Tim, Altermatt, Anna, Amann, Michael, Huber, Petra, Hürbin, Manuel, Ruberte, Esther, Thöni, Alain, Würfel, Jens, Zuber, Vanessa, Coslovsky (Head), Michael, Neuschwander, Pia, Simon, Patrick, Wunderlin, Olivia, Schmid, Ramun, Baumann, Christian, Hämmerle, Peter, Schlageter, Vincent, Coslovsky, Michael, Coduri, Federica, Blum, Manuel R., Stauber, Annina, Beer, Jürg, and Zuern, Christine S.

Published
2024
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42. Immune checkpoint inhibition and single fraction stereotactic radiosurgery in brain metastases from non-small cell lung cancer: an international multicenter study of 395 patients

Author

Lehrer, Eric J., Khosla, Atulya A., Ozair, Ahmad, Gurewitz, Jason, Bernstein, Kenneth, Kondziolka, Douglas, Niranjan, Ajay, Wei, Zhishuo, Lunsford, L. Dade, Mathieu, David, Trudel, Claire, Deibert, Christopher P., Malouff, Timothy D., Ruiz-Garcia, Henry, Peterson, Jennifer L., Patel, Samir, Bonney, Phillip, Hwang, Lindsay, Yu, Cheng, Zada, Gabriel, Picozzi, Piero, Franzini, Andrea, Attuati, Luca, Prasad, Rahul N., Raval, Raju R., Palmer, Joshua D., Lee, Cheng-chia, Yang, Huai-che, Fakhoury, Kareem R., Rusthoven, Chad G., Dickstein, Daniel R., Sheehan, Jason P., Trifiletti, Daniel M., and Ahluwalia, Manmeet S.

Published
2023
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43. Epilepsy associated with cerebral cavernous malformations managed with stereotactic radiosurgery: an international, multicenter study

Author

Dumot, Chloe, Mantziaris, Georgios, Pikis, Stylianos, Dayawansa, Sam, Xu, Zhiyuan, Samanci, Yavuz, Ardor, Gokce D., Peker, Selcuk, Nabeel, Ahmed M., Reda, Wael A., Tawadros, Sameh R., Abdel Karim, Khaled, El-Shehaby, Amr M. N., Eldin, Reem M. Emad, Elazzazi, Ahmed H., Moreno, Nuria Martínez, Álvarez, Roberto Martínez, Liscak, Roman, May, Jaromir, Mathieu, David, Tourigny, Jean-Nicolas, Tripathi, Manjul, Rajput, Akshay, Kumar, Narendra, Kaur, Rupinder, Picozzi, Piero, Franzini, Andrea, Speckter, Herwin, Hernandez, Wenceslao, Brito, Anderson, Warnick, Ronald E., Alzate, Juan, Kondziolka, Douglas, Bowden, Greg N., Patel, Samir, and Sheehan, Jason P.

Published
2023
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44. Modal Analysis of 15 MW Semi-Submersible Floating Wind Turbine: Investigation on the Main Influences in Natural Vibration

Author

Arthur Harger, Lucas H. S. Carmo, Alfredo Gay Neto, Alexandre N. Simos, Guilherme R. Franzini, and Guilherme Henrique Rossi Vieira

Subjects
semi-submersible FOWT, modal analysis, added mass, Production of electric energy or power. Powerplants. Central stations, TK1001-1841
Abstract

One of the sources of sustainable energy with great, still untapped potential is wind power. One way to harness such potential is to develop technology for offshore use, more specifically at high depths with floating turbines. It is always critical that their structural designs guarantee that their natural frequencies of vibration do not match the frequencies of the most important oscillatory loads to which they will be subjected. This avoids resonance and its excessive undesired oscillatory responses. Based on that, a 3D finite element model of a 15 MW semi-submersible floating offshore wind turbine was developed in the commercial software ANSYS Mechanical ® to study its dynamic behavior and contribute to the in-depth analysis of structural modeling of FOWTs. A tower and floating platform were individually modeled and coupled together. The natural frequencies and modes of vibration of the coupled system and of its components were obtained by modal analysis, not only to verify the resonance, but also to investigate the determinant factors affecting such behaviors, which are not extensively discussed in literature. It was found that there is strong coupling between the components and that the tower affects the system as a result of its stiffness, and the floater as a result of its rotational inertia. The platform’s inertia comes mainly from the ballast and the effects of added mass, which was considered to be a literal increase in mass and was modeled in two manners: first, it was approximately calculated and distributed along the submerged flexible platform members and then as a nodal inertial element with the floater being considered as a rigid body. The second approach allowed an iterative analysis for non-zero frequencies of vibration, which showed that a first approximation with an infinite period is sufficiently accurate. Furthermore, the effects of the mooring lines was studied based on a linear model, which showed that they do not affect the boundary conditions at the bottom of the tower in a significant way.

Published
2023
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47. Phase diagram of SALR fluids on spherical surfaces

Author

Franzini, Stefano, Reatto, Luciano, and Pini, Davide

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

We investigate the phase diagram of a fluid of hard-core disks confined to the surface of a sphere and whose interaction potential contains a short-range attraction followed by a long-range repulsive tail (SALR). Based on previous works in the bulk we derive a stability criterion for the homogeneous phase of the fluid, and locate a region of instability linked to the presence of a negative minimum in the spherical harmonics expansion of the interaction potential. The inhomogeneous phases contained within this region are characterized using a mean-field density functional theory. We find several inhomogeneous patterns that can be separated into three broad classes: cluster crystals, stripes, and bubble crystals, each containing topological defects. Interestingly, while the periodicity of inhomogeneous phases at large densities is mainly determined by the position of the negative minimum of the potential expansion, the finite size of the system induces a richer behavior at smaller densities.

Published
2021
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48. Sequential Normothermic Regional Perfusion and End-ischemic Ex Situ Machine Perfusion Allow the Safe Use of Very Old DCD Donors in Liver Transplantation

Author

Torri, Francesco, Balzano, Emanuele, Melandro, Fabio, Maremmani, Paolo, Bertini, Pietro, Lo Pane, Paolo, Masini, Matilde, Rotondo, Maria Isabella, Babboni, Serena, Del Turco, Serena, Antonelli, Stefano, De Tata, Vincenzo, Biancofiore, Giandomenico, Guarracino, Fabio, Paolicchi, Aldo, De Simone, Paolo, Basta, Giuseppina, Ghinolfi, Davide, Martinelli, Caterina, Bronzoni, Jessica, Menconi, Giacomo, Tauzi, Roeld, Palladino, Simona, Catalano, Gabriele, Tincani, Giovanni, Petruccelli, Stefania, Carrai, Paola, Bindi, Lucia, Esposito, Massimo, Franzini, Maria, Campani, Daniela, and Haxhiademi, Dorela

Published
2024
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49. Eucalyptus-Based Glued Laminated Timber: Evaluation and Prediction of Its Properties by Non-Destructive Techniques

Author

Ramon Ferreira Oliveira, Pedro Gutemberg de Alcântara Segundinho, João Gabriel Missia da Silva, Fabricio Gomes Gonçalves, Dercílio Junior Verly Lopes, Jeferson Pereira Martins Silva, Nayara Franzini Lopes, Leonor da Cunha Mastela, Juarez Benigno Paes, Clara Gaspar Fossi de Souza, Francisco Antônio Rocco Lahr, Maria Alice Romanha Belumat, André Luis Christoforo, and Caroline Palacio de Araujo

Subjects
glue line, polyurethane, physical and mechanical properties, resorcinol, glulam, drilling resistance, Plant ecology, QK900-989
Abstract

Eucalyptus-based glued laminated timber (glulam) was produced to determine the feasibility of a non-destructive method (drilling resistance) to predict the properties of structural elements and add value to lower-quality hardwood species. Glulam was manufactured with formaldehyde (Resorcinol), reference condition, and bio-based (Castor oil-based) adhesives in two assembly schemes, the core composed either of two continuous lamellae each 105 cm long, or of two formed by the juxtaposition of shorter boards (35 and 55 cm). The shear strength of the glue line (fv0), modulus of elasticity (Ec90), and strength (fc90) in compression perpendicular to the grain; delamination (DL); and main and extended glue line thicknesses were evaluated. The Resistograph equipment was used to perform the perforation perpendicular to the glue line (samples extracted from the glulam elements) to correlate the properties. The results of this research demonstrate that the scheme of the boards had little effect on the physical and mechanical properties evaluated (except the main glue line and delamination), and the drilling resistance (DR) presents a significant correlation with practically all properties evaluated (variations in density values and other properties are explained by variations in DR values), making it possible to estimate Ec90 and fc90 with desired precision (R2adj ≈ 80%). This highlights the feasibility of using this methodology in the quality control of glulam elements. It is concluded that regardless of the adhesive, elements comprising a 105 cm-length core and external lamellae (T1 and control) are indicated for external use, presenting low delamination. Short-length central lamellae adhesively glued with PUR (T2) are not recommended for external applications due to their susceptibility to delamination. However, T2 is indicated for internal environments due to its low production cost. This study also proved the efficiency of using models based on drilling resistance to estimate wood density and its resistance to compression perpendicular to the fiber.

Published
2024
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