Improving up-conversion with PBS quantum dots

This paper evaluates the enhancement of the up-conversion phenomena by combining rare-earth doped phosphors with PbS quantum dots (QDs). We present results on the characterization of two different ways of adhering the up-converter with this fluorescent material to bifacial solar cells: by dissolving the powder in a spin-on oxide and by dissolving it in a silicone gel. The improvement in photocurrent detected for both the oxide and silicone alternatives when including the QDs is 60% better than without them. It is shown that the absorption and emission characteristics of the PbS QDs embedded in oxide and silicone can be tuned into to the desired spectral region. Keywords: quantum dots, up-converter, solar cel

Upgrading pasta wastes through lactic acid fermentations

During its production process, every kilogram of pasta manufactured generates about 23 g of pasta wastes (PW). Considering the global pasta production, there are about 376 kilotonnes of PW produced every year. In this work, PW were characterised and used as the substrate in lactic acid (LA) fermentations. Enzymatic hydrolysis of 200 g/L of PW allowed for the liberation of sugars with a yield 0.81 gs/gdryPW. After the screening of several B. coagulans, the strain A559 was selected for experiments at the lab and pilot scales. Two fermentation modes were tested during lab scale experiments namely, simultaneous saccharification and fermentation and sequential hydrolysis and fermentation with the latter showing higher yields. The process was scaled up to 50 L where a LA concentration of 47.67 g/L and yield of 0.67 gLA/gdrydPW were achieved

Decision-making in information seeking on texts: an eye-fixation-related potentials investigation

Reading on a web page is known to be not linear and people need to make fast decisions about whether they have to stop or not reading. In such context, reading, and decision-making processes are intertwined and this experiment attempts to separate them through electrophysiological patterns provided by the Eye-Fixation-Related Potentials technique (EFRPs). We conducted an experiment in which EFRPs were recorded while participants read blocks of text that were semantically highly related, moderately related, and unrelated to a given goal. Participants had to decide as fast as possible whether the text was related or not to the semantic goal given at a prior stage. Decision making (stopping information search) may occur when the paragraph is highly related to the goal (positive decision) or when it is unrelated to the goal (negative decision). EFRPs were analyzed on and around typical eye fixations: either on words belonging to the goal (target), subjected to a high rate of positive decisions, or on low frequency unrelated words (incongruent), subjected to a high rate of negative decisions. In both cases, we found EFRPs specific patterns (amplitude peaking between 51 to 120 ms after fixation onset) spreading out on the next words following the goal word and the second fixation after an incongruent word, in parietal and occipital areas. We interpreted these results as delayed late components (P3b and N400), reflecting the decision to stop information searching. Indeed, we show a clear spill-over effect showing that the effect on word N spread out on word N + 1 and N + 2

The Emotional Experience of Mexican Women with SARS-CoV-2 during Pregnancy―A Qualitative Study

Pregnant women have been considered a high-risk group for SARS-CoV-2 infection; the impact of the disease on the health of a mother and her child is still being studied. The emotional impact of the pandemic on pregnant women has been extensively studied. Emotional distress is proposed as a perspective to explain the emotional manifestations in women during this stage as something common rather than pathological. The objective of this study was to explore the emotional experience of women who tested positive for SARS-CoV-2 towards the end of their pregnancy, during the first and second waves of COVID-19 in Mexico. A qualitative study was carried out: 18 pregnant women with COVID-19 were interviewed. A thematic analysis of the data was performed, resulting in 3 main themes and 14 subthemes. The COVID-19-infected mothers-to-be experienced mild to moderate emotional distress. It was more intense for those with comorbidities. This distress was aggravated during obstetrical complications and comorbidities, as well as during COVID-19 and postpartum. The emotional distress was appeased by both the perception of medical care and social support. The emotional distress of pregnant women with COVID-19 requires emotional support to reduce its impact

Secretion Mechanism across Wall

Yeast organisms are widely explored by humans for different biotechnological applications. During their growth, they need to adapt and interact themselves with the environment medium. For this purpose, organisms uptake nutrients and at the same time secrete different molecules include proteins to extracellular medium. This phenomenon requires the use of specialized structures to regulate entry and exit of molecules called transporters. Two transporters, namely Proteins and Vesicles, are specialized in translocating molecules in and out across the wall. The knowledge of these systems is important and served to bring novel applications of yeast. Taking together, this book chapter is divided into two parts: at first, it primarily accounts on few examples of protein (carbohydrates and peroxisome proteins) and vesicle (intracellular and extracellular vesicles) transporters of yeasts. Second, it deals with the recent advances of yeast applications in diverse area of science

Variación morfológica y reproductiva de nueve poblaciones naturales de Lupinus campestris Cham. & Schltdl. de la región centro oriente de Puebla, México

El género Lupinus L. (Fabaceae) es de alta calidad nutrimental por su alto porcentaje de proteína en semillas y follaje; útil para la restauración ecológica de suelos degradados por su capacidad para fijar nitrógeno. Para el estudio de diversidad genética existen marcadores; morfológicos y moleculares. El proceso de domesticación y obtención de variedades se basa en la caracterización morfológica del fenotipo, al estudiar la variabilidad morfológica entre diversas poblaciones naturales. El objetivo fue determinar la variación fenotípica, parámetros reproductivos y capacidad de fijación de nitrógeno a través de la reducción de acetileno de nueve poblaciones de L. campestris procedentes en un intervalo altitudinal del centro-oriente de Puebla, México. Se recolectó germoplasma, el cual se propagó en condiciones de invernadero. En la mayoría de las características evaluadas hubo diferencias significativas (p>0.001). La población de Atzitzintla produjo el número mayor de vainas (479), así como en peso total de semillas (22 g). La capacidad de fijación de N2 resultó mayor entre las plántulas procedentes de Tlalmotolo. Se observó variación significativa en las características morfológicas de las plantas y en el potencial reproductivo. En las semillas la variabilidad fue significativa entre y dentro de poblaciones

Relación entre parámetros edáficos y criterios de calidad postcosecha de frutos de Prunus persica (L.) Batsch por análisis multivariado

This study was carried out in the main Escarcha variety peach producing area in the state of Tlaxcala, Mexico. Soil parameters were evaluated in plots with different management and some quality criteria in the fruit, to later relate them through a Principal Component Analysis (PCA). The results of the soil characterization evidenced a predominance of the sand fraction, low concentration of organic matter and total N, and few exchange sites. Yields of 10.88 to 11.66 t ha-1 were obtained. Through the PCA it was observed that the predictor variables in the case of the soil, in the main component one (CP1) were organic matter, organic carbon, total nitrogen and phosphorus; in CP2 were the apparent density, porosity, pH and the humification index. In the case of the fruit, in CP1 were weight, equatorial diameter, maturity index and number of fruits, and in CP2 were total titratable acidity and firmness. The PCA allowed identifying the soil variables that influence the quality of the fruit. The producer is recommended to increase the contents of organic matter, total N and P to obtain a greater number of fruits per tree and fruits with an adequate size, weight and maturity index in the evaluated plots. The post-harvest quality criteria showed that this variety is suitable for fresh consumption, for the preparation of preserves, compotes, jams and syrups; in addition to being classified as sweet, according to the maturity index.Este estudio se llevó a cabo en la principal zona productora de durazno variedad Escarcha, Tlaxcala, México. Se evaluaron parámetros del suelo en parcelas con diferente manejo y algunos criterios de calidad en el fruto, para posteriormente relacionarlos a través de un Análisis de Componentes Principales (ACP). Los resultados de la caracterización del suelo evidenciaron un predominio de la fracción arena, baja concentración de materia orgánica y de N total, y pocos sitios de intercambio. Se obtuvieron rendimientos de 10,88 a 11,66 t ha-1. A través de los ACP se observó que las variables predictoras en el caso del suelo, en el componente principal 1 (CP1) fueron materia orgánica, carbono orgánico, nitrógeno total y fósforo; en el CP2 la densidad aparente, porosidad, pH y el índice de humificación. En el caso del fruto, en el CP1 fue el peso, diámetro ecuatorial, índice de madurez y número de frutos y en CP2 acidez total titulable y firmeza. El ACP permitió identificar las variables del suelo que influyen en la calidad del fruto. Se recomienda al productor incrementar los contenidos de materia orgánica, N total y P para obtener mayor número de frutos por árbol y frutos con un índice de madurez, tamaño y peso adecuados en las parcelas evaluadas. Los criterios de calidad postcosecha mostraron que esta variedad es apta para su consumo en fresco, para la elaboración de conservas, compotas, mermeladas y jarabes; además de clasificarse como dulces, según el índice de madurez

Effects of potential models on nitrogen adsorption on triangular pore: An improved mixed model for energetic characterization of activated carbon

Studies of the importance of shape considering both adsorption molecule and pore geometry were performed by Monte Carlo simulation in grand canonical ensemble (GCMC) for activated carbons (AC). The effects on adsorption capacity and isosteric heat were investigated in different pore sizes using a pseudo-sphere model and a multi-site potential (elongated shape) on triangular-shaped pore. The triangular geometry was considered as a need to allow for the simultaneous interaction of an adsorbed molecule with three graphite walls to account for the high values observed in the isosteric heat of adsorption at low pressures. Kernels of adsorption isotherms were generated by GCMC for different pore sizes considering two potential models for the determination of pore size distribution that allows for the characterization of various micro and mesoporous solids. We propose using a mixed geometry model (slit-triangular) and an elongated molecule potential to characterize activated carbons. The model is used to characterize a family of AC samples both texturally and energetically. The isosteric heat of adsorption was determined from the experimental isotherm by Monte Carlo simulation and the results were contrasted with experimental data obtaining a good agreement. In addition, the work reports the interesting result on the need to use multi-atom potential (together with the mixed model) to predict heat of adsorption values of the order of those reported experimentally.Fil: Delgado Mons, Rodrigo Nahuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Cornette, Valeria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Toso, Juan Pablo. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Física; ArgentinaFil: Soares Maia, Debora Aline. Universidade Estadual do Ceará; BrasilFil: López, Raúl Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentin

Enhancement of up-conversion efficiency by combining rare earth-doped phosphors with PbS quantum dots

This paper aims to enhance the up-conversion phenomena observed in silicon solar cells by combining a rare earth-doped phosphor with PbS quantum dots. Two different ways of adhering the up-converter and the fluorescent material to a bifacial solar cell are implemented: dissolving the powder in a spin-on oxide and by dissolving it in a silicone gel. Characterization is carried out through photocurrent and photoluminescence measurements. The improvement in photocurrent detected by the combination of the up-converter and the PbS quantum dots is 60% better than without them, demonstrating that the absorption and emission characteristics of the quantum dots embedded both in the oxide or the silicone can be tuned to the desired spectral region

La importancia de rehabilitar tepetate con Lupinus campestris Cham. & Schltdl.

El tepetate es un horizonte endurecido con baja retención de humedad y fertilidad, restrictivas para el desarrollo de especies vegetales; sin embargo, puede mejorar esta condición a través de prácticas de rehabilitación, como lo es el empleo de leguminosas. Se determinó la potencialidad de diferentes poblaciones de Lupinus campestris como alternativa para rehabilitar y mejorar la calidad productiva de los  tepetates  de la hacienda San  Antonio  Tepetzala, localizada en  el  municipio  de Atlangatepec, Tlaxcala. Se estableció un diseño experimental en bloques completamente al azar, los tratamientos fueron nueve poblaciones de L. campestris procedentes del estado de Puebla. A los 12 meses se llevó a cabo  el  muestreo  de  tepetate  de  la  zona  rizosférica  de  las  leguminosas,  para  evaluar  el  pH, conductividad eléctrica, materia orgánica, capacidad de intercambio catiónico, N total, P, K, Ca y Mg. Los resultados mostraron una diferencia significativa (p<0.05) después del establecimiento de la planta,pero no entre poblaciones. Si bien los valores de cada una de las variables determinadas con base a la normatividad mexicana fueron bajos,es notoria la mejora a un año de establecer diferentes poblaciones de L. campestris en el tepetate. Por lo que se concluye que L. campestris puede mejorar las características del tepetate, lo que la convierte en una excelente candidata para la rehabilitación de zonas degradadas