Investigating Piezochromic Properties of πconjugated Materials: a combined Raman and DFT Study

Π-conjugated materials have been studied for decades due to their great interest in organic electronics. Among them, piezochromic materials, which exhibit color changes resulting from external pressure or mechanical grinding, become very attractive from a scientific viewpoint owing to their potential applications as pressure-sensing and opticalrecording systems1. The main target of the present work is to develop a joint experimental and theoretical approach able to deliver crucial information for the understanding of the structural effects causing piezochromic changes. To this end, we will focus our attention on two families of -conjugated materials with potential application as sensors. The first one is a family of 9,10-Bis((E)-n(pyrid-2-yl)vinyl) anthracene, BPnVA (n=2 orto-,3 metha- and 4 para-) compounds, see Figure 1. Interestingly, these three compounds with varying position of the nitrogen on the external pyridyl group exhibit different molecular packing modes. Grinding and the application of external pressure on the powder also led to a strong change in their photoluminescence color.2 The second familiy is based on the N,N’-Bis-Boc-3,3’-di(pyren-1yl)-2,2’-biindole compound (compound 1c in Figure 1) which also shows photoluminescence under pressure application. However, the molecular packing induced by this phenomenon is still under study 3. In both cases, it will be also very interesting to determine how temperature affects the vibrational structure of these systems.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

“Education Network” a new way to teach Chemistry

The complexity of chemistry has implications for the teaching of chemistry. That chemistry is a very complex subject. The majority of the students at University think that chemistry is a difficult discipline and they have difficulty in understanding the concepts. Moreover, students' interest in chemistry decreases the first year at university. The reason for this decrease might be that the contents of chemistry laboratory classes are boring, out of date and lacking of dynamism that students experience through visual media tools. For these reasons, new programs and methodologies should be developed. Those are based on making chemistry relevant through problem solving and collaborative learning hold promise for reforming chemistry education. It is about an education according to circumstances, which is adapted to context and virtual behaviour of people. It's time to CRUSH boredom by transforming your classroom into an Escape Room adventure. School-based escape games are a great teaching tool. The students while playing, learn. The most important point is that they won’t realize they’re doing both at the same time. In this work, an educational gamification experience based on the escape room concept was developed. The first (Do It Yourself) DIY Escape Room was built the year before at Mechanical Engineer Degree started, that took more than three weeks of work. It was presented to other professors to the same subject at different degrees. That DIY Escape Room was modified and adapted to each group. Each professor changed the clues, problems and so on in order to orientate the topic as much as possible to their students.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Theoretical understanding of the increment of upon protonation of pyridine peripheral octupolar molecules: Toward nonlinear optical sensors

6 pages, 6 tables, 4 figures.In this article, we present a computational study of the nonlinear optical properties of pyridine-based octupolar molecules in their neutral and fully triprotonated states. The effect of the core substitution and the degree of conjugation with the periphery has been also established and confirms the possibility of fine-tuning the nonlinear optical response. Computations involving the time-dependent density-functional theory approach serve to further explore the existence of excited states with nonzero dipole moment. From these results, the origin of the high second-order nonlinear optical activity upon protonation is addressed.The present work was supported in part by the Dirección General de Enseñanza Superior DGES, MEC, Spain through research Project Nos. CTQ2006-14987-C02-01 and CTQ2005-01368. The authors are also indebted to Junta de Andalucía and Gobierno de Aragón Spain for funding their research groups FQM-0159 and E39. M.C.R.D. is grateful to the MEC/Fulbright for her Postdoctoral Fellowship at the Georgia Institute of Techology. J.C. is grateful to the MEC of Spain for an I3 professorship position of Chemistry at the University of Málaga and M.M.O. acknowledges the MEC for a personal grant.Peer reviewe

A message transmission system with lightweight encryption as a project in a Master subject

Master subjects should ideally be very practical, to allow students to apply the knowledge they have acquired to the solving of specific problems. This paper proposes the design of a secure communications system using an SPI bus as a Master subject. The system designed uses a stream cipher to encrypt and decrypt data and allows transmission of random length messages. It also uses CRCs to check message integrity.Ministerio de Ciencia e Innovación TEC-2010-1687

Experimental assessment of ignition characteristics of lubricating oil sprays related to low-speed pre-ignition (LSPI)

This is the author's version of a work that was accepted for publication in International Journal of Engine Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as https://doi.org/10.1177/14680874211013268[EN] Low-speed pre-ignition (LSPI) remains one of the challenges of Direct Injection (DI) Spark Ignition (SI) engines due to its potential to induce a heavy knock. Several mechanisms have been identified in the literature as plausible causes for LSPI. The physical and chemical properties of lubricant oils play a role on some of these causes. The present work aims at getting an independent procedure to determine the proneness of lubricant oils to ignite. To this end, the ignition delay (ID) of different oil formulations is experimentally determined in a constant-pressure flow facility through two different optical techniques: Schlieren and OH* chemiluminescence imaging. The investigation explores the effect of base-stock formulation, oil specification quality level, different additive types content, aging, and oxidation on oil reactivity for several thermodynamic conditions. Differences in ignition delay were found among base stocks, correlating with the American Petroleum Institute (API) group classification. However, no significant differences were found among additive packages previously reported to yield different LSPI occurrences. Hence, differences in reactivity among lubricating oil formulations are not the determining factor explaining their different LSPI occurrences in an engine. Similarly, specific lubricant additive content, aging, and oxidation do not importantly modify the measured ignition delay.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Part of the experimental hardware used in this work was purchased through funds obtained from IDIFEDER/2018/037 ``Diagnostico optico a alta velocidad para el estudio de procesos termo-fluidodinamicos en sistemas de inyeccion.''Tormos, B.; García-Oliver, JM.; Carreres, M.; Moreno-Montagud, C.; Domínguez, B.; Cárdenas, MD.; Oliva, F. (2022). Experimental assessment of ignition characteristics of lubricating oil sprays related to low-speed pre-ignition (LSPI). International Journal of Engine Research. 23(8):1327-1338. https://doi.org/10.1177/146808742110132681327133823

Virtual reality and physiotherapy in post-stroke functional re-education of the lower extremity: A controlled clinical trial on a new approach

Numerous Virtual Reality (VR) systems address post-stroke functional recovery of the lower extremity (LE), most of them with low early applicability due to the gait autonomy they require. The aim of the present study was to evaluate the feasibility of a specific VR treatment and its clinical effect on LE functionality, gait, balance, and trunk control post-stroke. A controlled, prospective, clinical trial was carried out with 20 stroke patients, who were divided into two groups: the first group (VR + CP; n = 10) received combined therapy of 1 h VR and 1 h of conventional physiotherapy (CP) and the second group (CP; n = 10) received 2 h of CP (5 days/week, for 3 weeks). The following pre-post-intervention measuring scales were used: Functional Ambulatory Scale (FAC), Functional Independence Measure (FIM), Fugl-Meyer Assessment (FM), Berg Balance Scale (BBS), and Trunk Control Test (TCT). Only VR + CP showed a significant improvement in FAC. In FIM, CP presented a tendency to significance, whereas VR + CP showed significance. Both groups improved significantly in FM (especially in amplitude/pain in VR + CP and in sensitivity in CP) and in BBS. In TCT, there was a non-significant improvement in both groups. The results indicate that the intervention with VR is a feasible treatment in the post-stroke functional re-education of the LE, with the potential to be an optimal complement of CP

Virtual Reality and Physiotherapy in Post-Stroke Functional Re-Education of the Lower Extremity: A Controlled Clinical Trial on a New Approach

Numerous Virtual Reality (VR) systems address post-stroke functional recovery of the lower extremity (LE), most of them with low early applicability due to the gait autonomy they require. The aim of the present study was to evaluate the feasibility of a specific VR treatment and its clinical effect on LE functionality, gait, balance, and trunk control post-stroke. A controlled, prospective, clinical trial was carried out with 20 stroke patients, who were divided into two groups: the first group (VR + CP; n = 10) received combined therapy of 1 h VR and 1 h of conventional physiotherapy (CP) and the second group (CP; n = 10) received 2 h of CP (5 days/week, for 3 weeks). The following pre-post-intervention measuring scales were used: Functional Ambulatory Scale (FAC), Functional Independence Measure (FIM), Fugl-Meyer Assessment (FM), Berg Balance Scale (BBS), and Trunk Control Test (TCT). Only VR + CP showed a significant improvement in FAC. In FIM, CP presented a tendency to significance, whereas VR + CP showed significance. Both groups improved significantly in FM (especially in amplitude/pain in VR + CP and in sensitivity in CP) and in BBS. In TCT, there was a non-significant improvement in both groups. The results indicate that the intervention with VR is a feasible treatment in the post-stroke functional re-education of the LE, with the potential to be an optimal complement of CP

Quantum chemical DFT and spectroscopic UV-Vis-NIR analysis of a series of push-pull oligothiophenes end capped by amino-cyanovinyl groups

A series of push-pull chromophores built around thiophene-based -conjugating spacers and bearing various types of amino-donors and cyanovinyl-acceptors have been analyzed by means of UV-Vis- NIR spectroscopic measurements. Density functional theory (DFT) calculations have also been performed to help the assignment of the most relevant electronic features and to derive useful information about the molecular structure of these NLO-phores. The effects of the donor/acceptor substitution in the electronic and molecular properties of the -conjugated spacer have been addressed. The effectiveness of the intramolecular charge transfer (ICT) has also been tested as a function of the nature of the end groups (i.e., electron-donating or electron-withdrawing capabilities).Research at the University of Málaga was supported by the Ministerio de Educación y Ciencia (MEC) of Spain through project CTQ2006-14987-C02-01, and by the Junta de Andalucía for funding our FQM- 0159 scientific group. J.C. is grateful to the Ministerio de Ciencia y Tecnología of Spain for a Ramón y Cajal position of Chemistry at the University of Málaga. M.C.R.D. is also grateful to the Ministerio de Educación y Ciencia of Spain for a personal grant. The group at the University of Minho acknowledges the Foundation for Science and Technology (Portugal) for financial support through Centro de Química (UM) and through POCTI, FEDER (ref. POCTI/QUI/37816/2001). M. Manuela M. Raposo and A. Maurício C. Fonseca are also grateful to Professor G. Kirsch from University of Metz (France) for his collaboration

Arqueometria antropológica en el sepulcro megalítico de El Palomar: contribución al conocimiento histórico de la campiña sevillana

Presentamos un estudio de la analítica realizada en huesos humanos encontrados en el interior de la estructura dolménica de El Palomar que ha sido realizada en la Universidad Autónoma de Barcelona. Este trabajo se integra en el Proyecto de Investigación que sobre Análisis del Proceso Cultural Operado en las Sociedades Agrarias de la Campiña Sevillana se está llevando a cabo en el Departamento de Prehistoria y Arqueología de la Universidad de Sevilla