3,783 research outputs found
Oscillatory relaxation of zonal flows in a multi-species stellarator plasma
The low frequency oscillatory relaxation of zonal potential perturbations is
studied numerically in the TJ-II stellarator (where it was experimentally
detected for the first time). It is studied in full global gyrokinetic
simulations of multi-species plasmas. The oscillation frequency obtained is
compared with predictions based on single-species simulations using simplified
analytical relations. It is shown that the frequency of this oscillation for a
multi-species plasma can be accurately obtained from single-species
calculations using extrapolation formulas. The damping of the oscillation and
the influence of the different inter-species collisions is studied in detail.
It is concluded that taking into account multiple kinetic ions and electrons
with impurity concentrations realistic for TJ-II plasmas allows to account for
the values of frequency and damping rate in zonal flows relaxations observed
experimentally.Comment: 11 figures, 22 page
Characterisation of apple cider cultivars by chemometric techniques using data from high-performance liquid chromatography and flow-injection analysis
Analytical techniques (HPLC and flow-injection analysis) for determining sugars, organic acids, polyphenols and pectins in apples, were employed along with chemometrics in the ripening and classification studies of cider apples. The use of principal component analysis allowed the authors to reduce the dimensionality of the data matrix; three new variables were obtained that accounted for 76% of variance. The projection of the apple cultivars in the reduced space allowed us to visualize the data structure on the basis of the degree of ripening and technological characteristics of the cider apple varieties monitored. Linear discriminant analysis computed a canonical variable with a prediction capacity of 93%, using three groups for cancellation in order to validate the method. The use of modelling techniques, such as SIMCA and partial least squares made an adequate grouping of apple cultivars feasible on the basis of their degree of ripening
Aplicació d'un sistema intel.ligent per al control d'una estació depuradora d'aigües residuals
Self-organization of ultrasound in viscous fluids
We report the theoretical and experimental demonstration of pattern formation
in acoustics. The system is an acoustic resonator containing a viscous fluid.
When the system is driven by an external periodic force, the ultrasonic field
inside the cavity experiences different pattern-forming instabilities leading
to the emergence of periodic structures. The system is also shown to possess
bistable regimes, in which localized states of the ultrasonic field develop.
The thermal nonlinearity in the viscous fluid, together with the
far-from-equilibrium conditions, are is the responsible of the observed
effects
Short communication. Cloning and sequencing of partial genomic DNA fragments corresponding to the S11 and S12 alleles of the Spanish almond cultivar ''Marcona''
This paper reports the cloning and partial genomic DNA sequencing of two S-RNases (S11 and S12) of almond. DNA from the Spanish almond cultivar Marcona, the most highly appreciated in Spain, was amplified by PCR using the primer pair AS1II and AmyC5R designed for the conserved regions of almond S-alleles. The cloned and sequenced S11 allele of cv. Marcona appears to be identical to that of cvs. Rumbeta and Bertina (which have been previously cloned and sequenced). This is the first time, however, that S12 has been sequenced in almond. The amplified and cloned S12 allele fragment possessed 1080 bp corresponding to the second intron and 506 bp corresponding to the second and third exons. The product of PCR-specific amplification showed that cv. Marcona and the Portuguese cultivar Pestaneta carry the same S12 allele. Knowledge of the sequences of these alleles will be helpful in the design of specific primers for S11 and S12, and could be of use when employing antisense techniques in genetic engineering projects.Este trabajo muestra la clonación y el análisis de secuencias de fragmentos de DNA genómico correspondientes a dos S-RNasas (S11 y S12) de almendro. Estos fragmentos se amplificaron mediante PCR a partir de DNA del cultivar 'Marcona', el más apreciado en el mercado español, utilizando la pareja de cebadores AS1II y AmyC5R, diseñados en regiones conservadas de los alelos S de almendro. El alelo S11 fue clonado y secuenciado en 'Marcona', y es idéntico al clonado y secuenciado previamente en 'Rumbeta' y 'Bertina'. En cambio, es la primera vez que el alelo S12 se secuencia en almendro. El fragmento analizado de este alelo contiene el segundo intrón (1080 pb) y secuencias parciales del segundo y tercer exón (506 pb). La amplificación específica por PCR mostró que el cultivar español 'Marcona' y el portugués 'Pestaneta' poseen el mismo alelo S12. La secuenciación de estos alelos permitirá, no sólo diseñar cebadores específicos para S11 y S12, sino también aplicar posiblemente la tecnología anti-sentido en ingeniería genética
Recession, employment and self-rated health: a study on the gender gap
Objectives: Employment status and economic recession have been associated with negative effects on self-rated health, and this effect differs by gender. We analysed the effects of the Spanish economic recession in terms of self-rated health, its differential effect among genders and its influence on gender gap. Study design: Repeated cross-sectional study using Spanish health surveys (2001–2014). Methods: Logistic regression models were conducted to explore the association between self-rated health and employment status and its evolution over time and gender. To test the impact of the economic recession, pooled data regression models were conducted. Results: In this study, we considered 104,577 subjects. During the last 15 years, women have entered the labour market, leading to wide changes in the Spanish traditional family roles. Instead of an increasing proportion of women workers, gender employment differences persist. Therefore, in 2014, the prevalence of workers was 55.77% in men, whereas in women, it was 44.01%. Self-rated health trends during the economic recession differ by gender, with women improving slightly their self-rated health from a low self-rated health prevalence of 38.76% in 2001 to 33.78% in 2014. On the contrary, men seem more vulnerable to employment circumstances, which have led to substantial reduction in the gender gap. Conclusions: Although a gender gap persists, the change in socio-economic roles seems to increase women's self-rated health, reducing this gap. It is important to promote women's labour market inclusion, even in economic recession periods
Design of in-building wireless networks deployments using evolutionary algorithms
In this article, a novel approach to deal with the design of in-building wireless networks deployments is proposed. This approach known as MOQZEA (Multiobjective Quality Zone Based Evolutionary Algorithm) is a hybr id evolutionary algorithm adapted to use a novel fitness function, based on the definition of quality zones for the different objective functions considered. This approach is conceived to solve wireless network design problems without previous information of the required number of transmitters, considering simultaneously a high number of objective functions and optimizing multiple configuration parameters of the transmitters
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