A focus on sustainable energy management for self-powered IoT devices via indoor photovoltaics

The future of information technologies lies in the form of trillions of autonomous ‘smart objects’ that can sense and communicate with their environment delivering pervasive and ubiquitous computing beyond today's imagination. Michaels et al. (H. Michaels, M. Rinderle, I. Benesperi, R. Freitag, A. Gagliardi and M. Freitag, Chem. Sci., 2023, 14, 5350, https://doi.org/10.1039/D3SC00659J) have achieved a key milestone in this context by developing an integrated autonomous and light-powered Internet of Things (IoT) system. They also show that dye-sensitized solar cells are particularly well-suited for this purpose with an indoor power conversion efficiency of 38%, far surpassing conventional silicon photovoltaics and alternative indoor photovoltaics technologies

Rehabilitar en psiquiatría ¿quema al personal de enfermería?

The aim of this study was to analyze the burnout on nurses dedicated to inpatient psychiatric rehabilitation. This took into account the three specific dimensions of the syndrome (emotional exhaustion, depersonalization and lack of professional accomplishment), organizational type variables as potential sources of stress, the consequences for the physical, psychological, social and family labor and the role played in the development of this process of socio-demographic variables and personality. These data, which includes the questionnaire CDPE-A Moreno Jiménez, on a sample of 42 nurses Psychiatric Rehabilitation Hospital O Rebullón of Vigo (Spain), were analyzed by descriptive and inferential statistics.The results indicate a low presence of burnout syndrome in the study population. Low relevance of sociodemographic and work variables with significant bivariate level effects only in terms of age and children, and no main effects multivariate level. However we show high levels in all dimensions of the scale of hardiness, and strong coping mechanisms both directly and in the perception of social support, which makes it possible to interpret these variables may be intervening as protective factors against development of the syndrome and thus may serve as indicators of occupational health and quality of care.El objetivo de este estudio fue analizar el desgaste profesional en el personal de enfermería dedicado a la rehabilitación psiquiátrica hospitalaria. Para ello se tuvieron en cuenta tanto las tres dimensiones específicas de este síndrome, es decir, agotamiento emocional, despersonalización y falta de realización profesional, además de otras variables organizacionales como posibles fuentes de estrés y las consecuencias para la salud física, psicológica, sociofamiliar y laboral; así como el papel desempeñado en el desarrollo de este proceso de algunas variables sociodemográficas y de personalidad. Estos datos, que recoge el cuestionario CDPE-A de Moreno Jiménez, sobre una muestra de 42 profesionales de enfermería del Hospital de Rehabilitación Psiquiátrica O Rebullón de Vigo (España), fueron analizados a través de estadística descriptiva e inferencial.Los resultados evidencian una baja presencia del síndrome de desgaste profesional en esta población de estudio, con poca relevancia de las variables sociodemográficas y laborales estudiadas, encontrando efectos significativos a nivel bivariado sólo en función de edad  e hijos, y sin efectos principales a nivel multivariante; sin embargo, nos muestran unos niveles altos en todas las dimensiones de la escala de la personalidad resistente, así como fuertes mecanismos de afrontamiento tanto directo como en la percepción de apoyo social, lo que posibilita interpretar que estas variables pudieran estar interviniendo como factores preventivos ante el desarrollo del síndrome y por tanto podrían servir de indicadores de salud laboral y calidad asistencia

Influence of the orientation of methylammonium lead iodide perovskite crystals on solar cell performance

Perovskite solar cells are emerging as serious candidates for thin film photovoltaics with power conversion efficiencies already exceeding 16%. Devices based on a planar heterojunction architecture, where the MAPbI(3) perovskite film is simply sandwiched between two charge selective extraction contacts, can be processed at low temperatures (<150 degrees C), making them particularly attractive for tandem and flexible applications. However, in this configuration, the perovskite crystals formed are more or less randomly oriented on the surface. Our results show that by increasing the conversion step temperature from room temperature to 60 degrees C, the perovskite crystal orientation on the substrate can be controlled. We find that films with a preferential orientation of the long axis of the tetragonal unit cell parallel to the substrate achieve the highest short circuit currents and correspondingly the highest photovoltaic performance

Highly Efficient Reproducible Perovskite Solar Cells Prepared by Low-Temperature Processing

In this work, we describe the role of the different layers in perovskite solar cells to achieve reproducible, similar to 16% efficient perovskite solar cells. We used a planar device architecture with PEDOT:PSS on the bottom, followed by the perovskite layer and an evaporated C-60 layer before deposition of the top electrode. No high temperature annealing step is needed, which also allows processing on flexible plastic substrates. Only the optimization of all of these layers leads to highly efficient and reproducible results. In this work, we describe the effects of different processing conditions, especially the influence of the C-60 top layer on the device performance

Magnetically propelled chained nanocomposites for biologically relevant media exploration

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGElongated nanostructures to be remotely and magnetically propelled in biologically relevant media, have gained attention as offering themselves as effective tools or carriers in theragnostics applications. However, the magnetic actuation associated remains challenging due to the lack of mechanical information in the media of interest, taking into account biophysical or biomedical purposes. In this study, we detail the magnetic actuation of magnetically propelled chained nanocomposites considering their dynamics, in which their velocity can be modulated in terms of the viscosity of the medium considered, given a magnetic field gradient. Simpler cases of distilled water, a water/glycerol mixture and a fluid made of cell extracts (imitating the cytosol of cells) of known viscosity are the basis experiments for the study of more complex media inside HeLa cells, murine NIH-3T3 fibroblasts and zebrafish larvae, offering the mechanical information required. The experimental results indicate that the magnetically propelled performance of the chained nanostructures can be precisely controlled in potentially changing scenarios, where drug and heat delivery, magnetic separation, or microfluidic technologies are demanded, using a magnetic field gradient and providing good estimations of the dynamical parameters involved.Xunta de Galicia | Ref. ED481A/322Xunta de Galicia | Ref. IN606A-2018/019Xunta de Galicia | Ref. IN853B 2018/03Ministerio de Economía y Competitividad | Ref. PI16/00496Instituto de Salud Carlos III | Ref. PI19/00349Instituto de Salud Carlos III | Ref. DTS19/00033Agencia Estatal de Investigación | Ref. MAT2016-81955-REDTAgencia Estatal de Investigación | Ref. PID2020-119242-I0

Layered perovskites in solar cells: structure, optoelectronic properties, and device design

Layered hybrid perovskites (LPKs) have emerged as a viable solution to address perovskite stability concerns and enable their implementation in wide-scale energy harvesting. Yet, although more stable, the performance of devices incorporating LPKs still lags behind that of state-of-the-art, multi-cation perovskite materials. This is typically assigned to their poor charge transport, currently caused by the choice of cations used within the organic layer. On balance, a compromise between efficiency and stability is sought, involving careful control of phase purity and distribution, interfaces and energy/charge transfer processes. Further progress is hindered by the difficulty in identifying the fundamental optoelectronic processes in these materials. Here, the high exciton binding energy of LPKs lead to the formation of multiple photoexcited species, which greatly complicate measurement interpretation. In this light, this review gives an overview of how complementary measurement techniques must be used to separate the contributions from the different species in order to identify device bottlenecks, and become a useful tool to narrow down the limitless list of organic cations. A move away from making compromises to mitigate the impact of poor charge transport is required. The root of the problem must be addressed instead through rational design of the interlayer cations

A closer look into two-step perovskite conversion with X-ray scattering

Recently, hybrid perovskites have gathered much interest as alternative materials for the fabrication of highly efficient and cost-competitive solar cells; however, many questions regarding perovskite crystal formation and deposition methods remain. Here we have applied a two-step protocol where a crystalline PbI2 precursor film is converted to MAPbI3–xClx perovskite upon immersion in a mixed solution of methylammonium iodide and methylammonium chloride. We have investigated both films with grazing incidence small-angle X-ray scattering to probe the inner film morphology. Our results demonstrate a strong link between lateral crystal sizes in the films before and after conversion, which we attribute to laterally confined crystal growth. Additionally, we observe an accumulation of smaller grains within the bulk in contrast with the surface. Thus, our results help to elucidate the crystallization process of perovskite films deposited via a two-step technique that is crucial for controlled film formation, improved reproducibility, and high photovoltaic performance

Bean yellow mosaic virus infecting broad bean in the green belt of Córdoba, Argentina

Broad bean (Vicia faba L) is the fourth most important pulse crop in the world. In Argentina, broad bean production was of 1,841 hectares and 16,500 tons during the 2017 growing season. Broad bean is commonly used in rotations; especially by farmers located in “green belts” that are peri-urban areas surrounding large cities that include horticultural family farms. Plants showing marked foliar mosaic symptoms, typical of viral infection, were collected during the 2015 growing season in the green belt of Córdoba city, Argentina. Preparations of symptomatic tissues were mechanically inoculated onto healthy broad bean plants in the greenhouse, which developed symptoms similar to those observed in the field. In addition, symptomatic samples were positive when tested by indirect ELISA with the anti-potyvirus group monoclonal antibody. Further, flexuous filamentous particles typical of potyviruses were observed under the electronic microscope on dip preparations. Lastly, total RNA was extracted from a symptomatic leaf and high-throughput sequenced, which allowed the assembly of a single virus sequence corresponding to a new highly divergent strain of Bean yellow mosaic virus (BYMV). Phylogenetic insights clustered this Argentinean broad bean isolate (BYMV-ARGbb) within group IX of BYMV. Given the economical importance of this virus and its associated disease, the results presented here are a pivotal first step oriented to explore the eventual incidence and epidemiological parameters of BYMV in broad bean in Argentina.Instituto de Patología VegetalFil: Rodriguez Pardina, Patricia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Nome Docampo, Claudia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Reyna, Pablo Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); ArgentinaFil: Reyna, Pablo Gastón. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Muñoz, Nacira Belén. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Muñoz, Nacira Belén. Universidad Nacional de Córdoba (UNC). Facultad de Ciencias Exactas Físicas y Naturales (FCEFyN).Cátedra de Fisiología Vegetal; ArgentinaFil: Arguello Caro, Evangelina Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Arguello Caro, Evangelina Beatriz. Universidad Nacional de Córdoba (UNC). Facultad de Ciencias Agropecuarias (FCA). Cátedra de Zoología Agrícola,; ArgentinaFil: Luque, Andres Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); ArgentinaFil: Luque, Andres Vicente. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Debat, Humberto Julio. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; Argentin

Temperature-dependent studies of exciton binding energy and phase-transition suppression in (Cs,FA,MA)Pb(I,Br)3_{3} perovskites

Multiple-cation mixed-halide (Cs,FA,MA)Pb(I,Br)3 perovskites containing cesium, formamidinium (FA), and methylammonium (MA) possess excellent properties for a wide range of optoelectronic applications such as thin-film photovoltaics or lasers. We investigate the role of excitons and the exciton binding energy EB, relevant for the effectiveness of charge separation in solar cells, as well as the temperature-dependent bandgap energy Eg which is used as an indicator for crystal phase transitions. Generalized Elliott fits of absorption spectra offer the possibility to determine both EB and Eg. However, since excitonic effects are non-negligible even at room temperature, a careful and detailed analysis of the spectra is crucial for a correct interpretation. Therefore, an additional evaluation based on a so-called f-sum rule is applied to achieve an improved reliability of the results at higher temperatures. The obtained EB values of 20–24 meV for Cs-containing mixed perovskite compounds are below the ones of 24–32 meV and 36–41 meV for pure methylammonium lead iodide (MAPbI3) and bromide (MAPbBr3), respectively, and, thus, facilitate charge-carrier separation in photovoltaic applications. Furthermore, temperature-dependent (T = 5–300 K) studies of Eg in (Cs,FA,MA)Pb(I,Br)3 indicate a suppressed crystal phase transition by the absence of any phase-transition related signatures such as the well-known jump of about 100 meV in MAPbI3. We verify these results using temperature-dependent electroreflectance spectroscopy, which is a very reliable technique for the direct and non-destructive determination of optical resonances of the absorber layer in complete solar cells. Additionally, we confirm the suppression of the phase transition in Cs0.05(FA0.83MA0.17)0.95Pb(I0.83Br0.17)3 by temperature-dependent X-ray diffraction

Blue-Green Color Tunable Solution Processable Organolead Chloride-Bromide Mixed Halide Perovskites for Optoelectronic Applications.

Solution-processed organo-lead halide perovskites are produced with sharp, color-pure electroluminescence that can be tuned from blue to green region of visible spectrum (425-570 nm). This was accomplished by controlling the halide composition of CH3NH3Pb(BrxCl1-x)3 [0 ≤ x ≤ 1] perovskites. The bandgap and lattice parameters change monotonically with composition. The films possess remarkably sharp band edges and a clean bandgap, with a single optically active phase. These chloride-bromide perovskites can potentially be used in optoelectronic devices like solar cells and light emitting diodes (LEDs). Here we demonstrate high color-purity, tunable LEDs with narrow emission full width at half maxima (FWHM) and low turn on voltages using thin-films of these perovskite materials, including a blue CH3NH3PbCl3 perovskite LED with a narrow emission FWHM of 5 nm.We acknowledge funding from the Engineering and Physical Sciences Research Council (EPSRC) and the Winton Programme (Cambridge) for the Physics of Sustainability. Support from the Deutsche Forschungsgemeinschaft (NIM Excellence Cluster) is gratefully acknowledged. A.S. acknowledges the funding and support from the Indo-UK APEX project. F.D. acknowledges funding and support from a Herchel Smith fellowship. M.D.V. acknowledges funding and support from the ERC-StG 337739-HIENA. A.S. thanks Dr. D. Di for the insightful discussions. P. D. gratefully acknowledges support from the European Union in the form of a Marie Curie Intra-European fellowship.This is the final version of the article. It first appeared from the American Chemical Society via http://dx.doi.org/10.1021/acs.nanolett.5b0236