A series of tricyanovinyl (TCV)-substituted oligothiophenes was synthesized and investigated with a number of physical methods including UV/Vis, IR, and Raman spectroscopy, nonlinear optical (NLO) measurements, X-ray diffraction, and cyclic voltammetry. Mono- or disubstituted oligomers were prepared by the reaction of tetracyanoethylene with mono- or dilithiated oligomers. The comparative effects of the symmetric and asymmetric substitutions in the electronic and molecular properties have been addressed. These oligomers display dramatic reductions in both their optical and electrochemical band gaps in comparison with unsubstituted molecules. The analysis of the electronic properties of the molecules was assisted by density functional theory calculations, which are in excellent agreement with the experimental data. TCV substitution influences the energies of the frontier orbitals, especially with respect to the stabilization of LUMO orbitals. X-ray structural characterization of a monosubstituted oligomer exhibits pi-stacking with favorable intermolecular interactions. NLO results agree with the role of the intramolecular charge-transfer feature in the asymmetric samples. These results furthermore exalt the role of conformational flexibility in the disubstituted compounds and reveal an unexpected nonlinear optical activity for symmetric molecules. Regarding the electronic structure, the interpretation of the vibrational data reflects the balanced interplay between aromatic and quinoid forms, finely tuned by the chain length and substitution pattern. The electronic and structural properties are consistent with the semiconducting properties exhibited by these materials in thin film transistors (TFTs).

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Many occupational accidents in construction sites are caused by the intrusion of a worker into a hazardous area. Technological solutions based on RFID, BIM, or UWB can reduce accidents, but they still have some limitations.The aim of the current paper is to design and evaluate a new system of “virtual fences” based on Bluetooth Low-Energy (BLE) to avoid intrusions. First of all, the system was designed using a number of beacons, a Bayesian filter, a finite state machine, and an indicator. Secondly, its safety attributes were evaluated based on a scientific questionnaire by an expert panel following the staticized groups’ methodology. Results showed that the proposal is inexpensive and easy to integrate and configure. The selected experts evaluated positively all the attributes of the system, and provided valuable insights for further improvements. From the experts’ discussions, we concluded that successful adoption of this “virtual fence” system based on BLE beacons should consider the influence of factors such as cost savings, top management support, social acceptance, and compatibility and integration with existing systems, procedures, and company culture. In addition, legislation updates according to technical advances would help with successful adoption of any new safety system.

Fall-from-height accidents are linked to severe and fatal consequences for impacted workers. A better understanding of the related variables is necessary to improve worker safety. This study analyzed all fall-from-height occupational accidents recorded in Spain from 2009 to 2019, selected significant variables, and evaluated the influence concerning the seriousness of the falls from height. Based on a total of 290,583 fall-from-height accidents, the study shows that a male inexperienced worker in a small company working in a non-habitual workplace is more likely to suffer fatal consequences once the accident happens. An improved knowledge of fall-from-height accidents will improve safety conditions. The workers should be trained and informed about their specific risk depending on the variables analyzed. Safety training should consider more risky profiles. Results from the current study can help identify suitable fall prevention and risk mitigation actions in safety programs for companies.

BACKGROUND: Occupational accidents among teachers are a cause of concern because of their consequences regarding several parts of the body, such as the neck, back, or extremities; however, the number of studies on this issue is limited. OBJECTIVE: To analyze the possible effects of different variables (gender, age, nationality, experience, sector, day of the week, traffic accidents) associated with occupational injuries suffered by teachers. METHODS: All teachers’ accidents recorded in Spain (136,702) from 2003 to 2018 were analyzed. Odds ratios with a 95% confidence interval were calculated. RESULTS: For injured female workers, being younger than 45, in her first month of experience, in a public school, without risk assessment, and in a traffic accident are the most important factors related to suffering a neck injury. In the case of injured male workers, to be older than 45, in a private school, and no traffic accidents are the factors detected influence suffering an injury in lower extremities. CONCLUSIONS: Institutions and schools should pay special attention to the highest-risk profiles. Results obtained can be a very useful tool for the design and implementation of specific occupational health and safety strategies adapted to the more vulnerable workers in each kind of injury.

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The integration of new technologies in schools and high schools are linked to new problems with the use and management of ITC tools as technostress between teachers. Technostress is associated with several negative effects on workers' health as anxiety, musculoskeletal disorders, headache, mental and physical fatigue. Due to the worldwide COVID19 pandemic, the majority of schools blocked out, and face to face courses were transformed into online courses in a very short time. In these circumstances, several teachers were forced to increase their skills with ICT technology to accomplish their teaching objectives, and their technological workload was higher than at the beginning of the course. In the current research, the technostress of teachers was evaluated based on a validated questionnaire. Results pointed out that occupational risks linked to technostress were high during the pandemic period. Older teachers showed more vulnerability to the risk, because a lack of training and adaptation of some of the new tools for online courses, while women showed higher levels of anxiety and emotional tension. Prevention measures as specific training programs for ICT, rational use of ICT, and a more balanced distribution of work and family life at home should be developed to address the problem.

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