Influencia de las levaduras en los procesos de fermentación y conservación de vinos blancos sobre polifenoles, polialcoholes y azúcares

Aislamiento y caracterización del esquema secuencial de las levaduras que realizan la fermentación de los mostos de uva de las variedades verdejo y jerez. Estudio de la microflora residual de levaduras durante la conservación de vinos blancos sometidos a diversos tratamientos de estabilización. Estudio de compuestos fenólicos de bajo peso molecular polialcoholes y azúcares en mostos de las variedades verdejo y jerez, en los fermentados obtenidos con distintos modelos fermentativos y confirmación de las variaciones debidas a éstos. Así, como en vinos elaborados industrialmente y tratados con anhídrido sulfuroso, o con enzimas pectolíticos o con los ácidos cítrico y ascórbico. Comprobación de la influencia que la madera ejerce sobre compuestos fenólicos de bajo peso molecular, polialcoholes y azúcare

Diseño y Desarrollo de un Índice Basado en Hiperplanos para Búsqueda en Espacios Métricos

109 p.La constante evolución de los datos en los últimos tiempos ha provocado que organizar la información con los métodos tradicionales se vuelva muy dificultoso. Es por esto que la investigación en esta área ha crecido bastante. Uno de los problemas más importantes al momento de administrar bases de datos con los métodos tradicionales, es que existen algunos conjuntos de datos donde la búsqueda exacta no tiene mayor sentido. En estos casos es necesario considerar la búsqueda por proximidad o similitud. Para enfrentar este nuevo problema los datos se pueden modelar como un espacio métrico (EM), que se de ne como el par (X; d), en que X denota el universo de objetos válidos y d una función de distancia (no negativa) entre cualquier par de objetos, que generalmente es costosa de calcular. Es por esta última razón que los EM se indexan con estructuras que permiten reducir el número de cálculos de distancia al momento de realizar búsquedas por similitud. Existen índices que permiten resolver consultas por similitud de forma exacta. Sin embargo, hay varios espacios métricos de interés práctico donde el rendimiento de estos índices decae. En estos casos existen alternativas no exactas, como por ejemplo el índice basado en permutantes (IBP). Este índice permite cambiar el espacio del problema a uno en donde es más barato calcular la distancia y de esta forma de finir un orden de revisión promisorio al momento de resolver las búsquedas. En esta memoria se proponen dos índices no exactos que utilizan una estrategia basada en el particionado por hiperplanos. En ellos cada elemento se representa con una firma binaria que es una secuencia de bits que se calcula a partir de los elementos que constituyen los hiperplanos. Similar al caso del IBP, al representar los elementos con firmas binarias se puede definir un orden promisorio de revisión. Una característica importante de este trabajo es la utilización de poco espacio de memoria. Para evaluar los índices propuestos, se realiza una comparación de rendimiento a mismo espacio de memoria utilizada con respecto al IBP. Los resultados obtenidos para el primer índice muestran un mejor comportamiento al momento de realizar búsquedas. Por su parte, aún cuando el segundo índice no logró superar a los permutantes es importante continuar con su investigación, ya que podría ser útil para categorizar a los elementos

Two-Color Pyrometer for Process Temperature Measurement During Machining

A fast fiber-optic two-color pyrometer operating on the optical communication bands is designed for temperature measurements in machining processes. Off-the-shelf low-loss fiber-optic demultiplexers and optoelectronics equipment are used in order to obtain a cost-effective sensing solution while reducing both the temperature measurement error and the minimum measurable temperature. The system is capable of measuring highly localized temperatures without using collimation lens. The designed pyrom-eter allows measuring temperature in the range from 300 to 650 °C, achieving a full-scale temperature error as low as 4%. Factors in-fluencing the temperature measurements are studied in order to identify the sensor limitations, such as a possible damage on the end of the optical fiber, the spectral loss attenuation and responsivity, or the distance between the fiber end and the target. Finally, this pyrometer is applied in a turning process, using a fiber-optic sensor embedded on a standard tool holder. Temperature measurements on the Inconel 718 are reported showing a good agreement with the simulations.This work was supported by the Spanish Ministry of Economía y Competitividad under Grants TEC2012-37983-C03-02, P2013/MIT-2790, and DPI2014-56137-C2-2-R.Publicad

Temperature Measurement and Numerical Prediction in Machining Inconel 718

Thermal issues are critical when machining Ni-based superalloy components designed for high temperature applications. The low thermal conductivity and extreme strain hardening of this family of materials results in elevated temperatures around the cutting area. This elevated temperature could lead to machining-induced damage such as phase changes and residual stresses, resulting in reduced service life of the component. Measurement of temperature during machining is crucial in order to control the cutting process, avoiding workpiece damage. On the other hand, the development of predictive tools based on numerical models helps in the definition of machining processes and the obtainment of difficult to measure parameters such as the penetration of the heated layer. However, the validation of numerical models strongly depends on the accurate measurement of physical parameters such as temperature, ensuring the calibration of the model. This paper focuses on the measurement and prediction of temperature during the machining of Ni-based superalloys. The temperature sensor was based on a fiber-optic two-color pyrometer developed for localized temperature measurements in turning of Inconel 718. The sensor is capable of measuring temperature in the range of 250 to 1200 °C. Temperature evolution is recorded in a lathe at different feed rates and cutting speeds. Measurements were used to calibrate a simplified numerical model for prediction of temperature fields during turning.This work was supported by the Spanish Ministry of Economy and Competitiveness and FEDER program under grants TEC2015-63826-C3-2-R and DPI2014-56137-C2-2-R, and from Comunidad de Madrid under grant S2013/MIT-2790

Degradation in seawater of structural adhesives for hybrid fibre-metal laminated materials

The adhesives used for applications in marine environments are subject to particular chemical conditions, which are mainly characterised by an elevated chlorine ion content and intermittent wetting/drying cycles, among others.These conditions can limit the use of adhesives due to the degradation processes that they experience. In this work, the chemical degradation of two different polymers, polyurethane and vinylester, was studied in natural seawater under immersion for different periods of time.The diffusion coefficients and concentration profiles of water throughout the thickness of the adhesiveswere obtained.Microstructural changes in the polymer due to the action of water were observed by SEM, and the chemical degradation of the polymer was monitored with the Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The degradation of the mechanical properties of the adhesive was determined by creep tests withMixed Cantilever Beam (MCB) specimens at different temperatures. After 180 days of immersion of the specimens, it was concluded that the J-integral value (depending on the strain) implies a loss of stiffness of 51% and a decrease in the failure load of 59% for the adhesive tested

Initial orientation vs maintenance of attention: Relationship with the severity of dependence and therapeutic outcome in a sample of cocaine use disorder patients

The visual probe paradigm allows for evaluating attentional bias (AB), distinguishing between approach vs avoidance patterns of attention and assessing two different processes when the exposure time to images is manipulated: initial orienting and maintenance of attention. The present study aimed to analyze the predictive capacity of these two processes for substance use disorder severity and therapeutic outcomes of patients with cocaine use disorder in treatment. The sample consisted of 70 outpatients who were starting treatment at a public service. AB was evaluated using a task based on the visual probe (VP) paradigm with images presented under two conditions: 200 ms vs 1000 ms. Cocaine and alcohol use disorder severity, craving, retention in treatment and relapse in consumption were recorded. Cocaine AB in the 1000 ms condition was negatively correlated with the cocaine use disorder severity (r = −0.26), whilst a positive correlation was found between cocaine craving and cocaine AB (r = 0.29). Alcohol use disorder severity negatively correlated with cocaine AB in the 200 ms condition (r = −0.24). Logistic regression analysis revealed that, after controlling for gender, age, and substance use disorder severity, cocaine AB in the 200 ms condition predicted dropout and relapse. Our results suggest that patients who adhere to treatment and remain abstinent tend to show avoidance in the 200 ms condition, with effect sizes of r = 0.29 and 0.30 respectively. The results suggest that training in avoidance strategies could be a valuable way of maintaining adherence and abstinence, as well as improving control of craving.Funding for open access charge: Universidad de Huelva / CBU

Diseño y desarrollo de un índice basado en hiperplanos para búsqueda en espacios métricos

109 p.La constante evolución de los datos en los últimos tiempos ha provocado que organizar la información con los métodos tradicionales se vuelva muy di cultoso.Es por esto que la investigación en esta área ha crecido bastante. Uno de los problemas más importantes al momento de administrar bases de datos con los métodos tradicionales, es que existen algunos conjuntos de datos donde la búsqueda exacta no tiene mayor sentido. En estos casos es necesario considerar la búsqueda por proximidad o similitud. Para enfrentar este nuevo problema los datos se pueden modelar como un espacio métrico (EM), que se de ne como el par (X; d), en que X denota el universo de objetos válidos y d una función de distancia (no negativa) entre cualquier par de objetos, que generalmente es costosa de calcular. Es por esta ultima razón que los EM se indexan con estructuras que permiten reducir el número de cálculos de distancia al momento de realizar búsquedas por similitud. Existen índices que permiten resolver consultas por similitud de forma exacta. Sin embargo, hay varios espacios métricos de interés práctico donde el rendimiento de estos índices decae. En estos casos existen alternativas no exactas, como por ejemplo el índice basado en permutantes (IBP). Este índice permite cambiar el espacio del problema a uno en donde es más barato calcular la distancia y de esta forma defi nir un orden de revisión promisorio al momento de resolver las búsquedas.En esta memoria se proponen dos índices no exactos que utilizan una estrategia basada en el particionado por hiperplanos. En ellos cada elemento se representa con una rma binaria que es una secuencia de bits que se calcula a partir de los elementos que constituyen los hiperplanos. Similar al caso del IBP, al representar los elementos con rmas binarias se puede de nir un orden promisorio de revisión.Una característica importante de este trabajo es la utilización de poco espacio de memoria.Para evaluar los índices propuestos, se realiza una comparación de rendimiento a mismo espacio de memoria utilizada con respecto al IBP. Los resultados obtenidos para el primer índice muestran un mejor comportamiento al momento de realizar búsquedas. Por su parte, aún cuando el segundo índice no logró superar a los permutantes es importante continuar con su investigación, ya que podría ser útil para categorizar a los elementos

Effect of the temperature in the mechanical properties of austenite, ferrite and sigma phases of duplex stainless steels using hardness, microhardness and nanoindentation techniques

The aim of this work is to study the hardness of the ferrite, austenite and sigma phases of a UNS S32760 superduplex stainless steel submitted to different thermal treatments, thus leading to different percentages of the mentioned phases. A comparative study has been performed in order to evaluate the resulting mechanical properties of these phases by using hardness, microhardness and nanoindentation techniques. In addition, optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) have been also used to identify their presence and distribution. Finally, the experimental results have shown that the resulting hardness values were increased as a function of a longer heat treatment duration which it is associated to the formation of a higher percentage of the sigma phase. However, nanoindentation hardness measurements of this sigma phase showed lower values than expected, being a combination of two main factors, namely the complexity of the sigma phase structure as well as the surface finish (roughness)

Transcriptomic response of Sinorhizobium meliloti to the predatory attack of Myxococcus xanthus

Bacterial predation impacts microbial community structures, which can have both positive and negative effects on plant and animal health and on environmental sustainability. Myxococcus xanthus is an epibiotic soil predator with a broad range of prey, including Sinorhizobium meliloti, which establishes nitrogen-fixing symbiosis with legumes. During the M. xanthus-S. meliloti interaction, the predator must adapt its transcriptome to kill and lyse the target (predatosome), and the prey must orchestrate a transcriptional response (defensome) to protect itself against the biotic stress caused by the predatory attack. Here, we describe the transcriptional changes taking place in S. meliloti in response to myxobacterial predation. The results indicate that the predator induces massive changes in the prey transcriptome with up-regulation of protein synthesis and secretion, energy generation, and fatty acid (FA) synthesis, while down-regulating genes required for FA degradation and carbohydrate transport and metabolism. The reconstruction of up-regulated pathways suggests that S. meliloti modifies the cell envelop by increasing the production of different surface polysaccharides (SPSs) and membrane lipids. Besides the barrier role of SPSs, additional mechanisms involving the activity of efflux pumps and the peptide uptake transporter BacA, together with the production of H2O2 and formaldehyde have been unveiled. Also, the induction of the iron-uptake machinery in both predator and prey reflects a strong competition for this metal. With this research we complete the characterization of the complex transcriptional changes that occur during the M. xanthus-S. meliloti interaction, which can impact the establishment of beneficial symbiosis with legumes