Synthesis, characterization and photo physical-theoretical analysis of D-π-A compounds. 2. Chain length effect through even-odd effect on the photophysical properties

In the continuous search for new compounds for solar devices, the family of dipolar D-π-A molecules, which have a donor (D) and an acceptor (A) charge joined by a conjugate bridge, have been the focus of attention in the recent years due their different properties. As we have shown before, there is a connection between the geometry of molecules based on tertiary asymmetric amines and their quantum yield. In the current work, four new compounds based on the same backbone molecule ((E)-2-cyano-3-(5-((E)-2-(9,9-diethyl-7-(phenylamino)-9H-fluoren-2-yl)vinyl)thiophen-2-yl)acrylic acid), but with different substituent, were synthesized. It is shown that the chain-size of the substituent group modifies the quantum yield. The news substituents introduced are a propyl (M8-3), butyl (M8-4), pentyl (M8-5) or hexyl (M8-6) group. In general, it was possible to see that the new substituents were able to increase their performances. Furthermore, an odd-even substituent effect, between propyl/pentyl and butyl/hexyl, was found and the theoretical geometrical data was able to follow the trend. However, theoretically, this substituent effect was inverted in the case of M8-3 and M8-4, which may be due to the disappearance in the emission patterns of an excited state close to 450 nm (at λ2), as it was shown in the experimental data. The most suitable behaviour belongs to [(E)-2-cyano-3-(5-((E)-2-(9,9-diethyl-7-(phenyl(propyl)amino)-9H-fluoren-2-yl)vinyl)thiophen-2-yl)acrylic acid] (M8-3). M8-3 has the highest quantum yields on average in all studied solvents; even higher than the last reported compounds with methyl (M8-1) and ethyl (M8-2) groups. Theoretically, the most likely explanation is that the dihedral angle formed between the carbonyl acceptor and nitrogen electron donor (Aryl-CO), should be as small as the molecule M8-3. This isolated compound has an average quantum yield including all solvents of 58.1% (average value), showing that a long group is not necessary to improve the performance

Relationship between photo-physical and electrochemical properties of D-π-A compounds regarding solar cell applications. 1. Substituent type effect in photovoltaic performance

Studying the electrochemical characteristics is an important step for determining interactions between molecules and the chemical environment. Moreover, the electrochemical evaluation of dyes is highly needed to establish the behavior of electro-active chemical species inside dye-sensitized solar cells (DSSCs). Four compounds, M8-1, M8-2, M8-O1, and M8-O2 (with a common organic structure (E)-2-cyano-3-(5-((E)-2-(9,9-diethyl-7-(phenylamino)-9H-fluoren-2-yl)vinyl)thiophen-2-yl)acrylic acid), are studied in two solvents, tetrahydrofuran (THF) and dimethylsulfoxide (DMSO). Among the studied compounds, M8-1 has highlighted characteristics compared with the others: its ground and excited states oxidation potential are the highest (1.14 and −1.22 V, respectively). Also, it shows the lowest energy gap between the excited state oxidation potential and the TiO2 conduction band. Relating to the substituent effect, the shorter the length, the higher the energetic difference in the electronic transition (M8-1 and 2). Comparing characteristics through quantum chemistry, the values obtained in DMSO are the most predictable. The injection energies signal that M8-1 is the best injector. The performances in solar cells are measured in three TiO2 materials: Degussa (D-TiO2), active opaque (A-TiO2), and transparent (T-TiO2). The IPCE results show the A > T > D average tendency, and the family of substituted alkyl has higher values than the alcoxyl one. Furthermore, in the first family the methyl substituent has a higher value than the ethyl one. M8-1 has the highest IPCE value, on average. In terms of efficiency, the alkyl substituted family again has higher values than the alcoxyl family. On average, the methyl substituent has a higher value than the ethyl one in both families. M8-1 has the highest efficiency value

Consideraciones para una adecuada descripción de perfiles de suelos

The existing soil profile description systems were done systematicaly based on land capability, keeping out genetic criteria, for instance. So that, the application of these systems for soil genesis studies will be problematic. In the other hand, the terminology to use is showed as a complex one and could drive us to make mistakes when we can see the same adjetive califing different things on different systems.Los sistemas para descripción de perfiles de suelos existentes, se han hecho sistemáticamente, en base a capacidades de uso de la tierra, dejando aparte criterios genéticos, por ejemplo. Así, la aplicación de estos sistemas a estudios de génesis de suelos resulta problemática. Por otra parte, la terminología a usar puede resultar compleja y llevar a errores, cuando vemos que el mismo adjetivo califica cosas distintas en diferentes sistemas

Necesidades de la familia cuidadora con un miembro diagnosticado de Esclerosis Lateral Amiotrófica

Introducción: La Esclerosis Lateral Amiotrófica (ELA) es una enfermedad degenerativa del sistema nervioso de carácter progresivo. Aunque se desconoce la causa y no existe una cura definitiva, la atención multidisciplinar brindada por la familia puede mejorar la calidad de vida del paciente, pero puede ser una tarea difícil y desalentadora. La ELA afecta tanto al paciente como a la familia, de ahí la relevancia del rol del cuidador y la necesidad de atender su sobrecarga. Objetivo: Conocer las necesidades de las familias cuidadoras con un miembro diagnosticado de ELA. Metodología: Se ha llevado a cabo una revisión narrativa de la literatura realizando una búsqueda bibliográfica en las bases de datos PubMed, CINAHL y PsycINFO durante los meses de octubre y noviembre de 2022. Resultados: A través del análisis de los artículos seleccionados se detectan las siguientes necesidades: Informativas, prácticas y físicas, sociales, y psicológicas, emocionales y espirituales. Conclusiones: La revisión actual amplía la comprensión de la vida diaria de las familias cuidadoras con un miembro diagnosticado de ELA, y sus necesidades de atención y cuidado.Introduction: Amyotrophic Lateral Sclerosis (ALS) is a progressive degenerative disease of the nervous system. Although the cause is unknown and there is no definitive cure, multidisciplinary care provided by the family can improve the patient's quality of life, but it can be a difficult and daunting task. ALS affects both the patient and the family, hence the importance of the role of the caregiver and the need to address caregiver overload. Objective: To understand the needs of family carers with a member diagnosed with ALS. Methodology: A narrative review of the literature was carried out by conducting a literature search in the PubMed, CINAHLl and PsycINFO databases during October and November 2022. Results: Through the analysis of the selected articles, the following needs are identified: informational, practical and physical, social and psychological, emotional and spiritual. Conclusions: The current review expands the understanding of the daily life of family caregivers with a member diagnosed with ALS, and their care needs

Phenotyping conservation agriculture management effects on ground and aerial remote sensing assessments of maize hybrids performance in Zimbabwe

n the coming decades, Sub-Saharan Africa (SSA) faces challenges to sustainably increasefood production while keeping pace with continued population growth. Conservation agriculture(CA) has been proposed to enhance soil health and productivity to respond to this situation.Maize is the main staple food in SSA. To increase maize yields, the selection of suitable genotypes andmanagement practices for CA conditions has been explored using remote sensing tools. They may playa fundamental role towards overcoming the traditional limitations of data collection and processing inlarge scale phenotyping studies. We present the result of a study in which Red-Green-Blue (RGB) andmultispectral indexes were evaluated for assessing maize performance under conventional ploughing(CP) and CA practices. Eight hybrids under different planting densities and tillage practices weretested. The measurements were conducted on seedlings at ground level (0.8 m) and from an unmannedaerial vehicle (UAV) platform (30 m), causing a platform proximity effect on the images resolution thatdid not have any negative impact on the performance of the indexes. Most of the calculated indexes(Green Area (GA) and Normalized Difference Vegetation Index (NDVI)) were significantly affectedby tillage conditions increasing their values from CP to CA. Indexes derived from the RGB-imagesrelated to canopy greenness performed better at assessing yield differences, potentially due to thegreater resolution of the RGB compared with the multispectral data, although this performance wasmore precise for CP than CA.The correlations of the multispectral indexes with yield were improvedby applying a soil-mask derived from a NDVI threshold with the aim of corresponding pixels withvegetation. The results of this study highlight the applicability of remote sensing approaches basedon RGB images to the assessment of crop performance and hybrid choice