170 research outputs found
Elemental Profile and 207Pb/206Pb, 208Pb/206Pb, 204Pb/206Pb, 87Sr/86Sr Isotope Ratio as Fingerprints for Geographical Traceability of Romanian Wines
Geographical wine traceability is an important topic in the context of wine authentification. Therefore, many researchers have addressed this subject by developing different methodologies based on multivariate analysis of organic and inorganic parameters and also by isotopic signature. The goal of this research was to assess the potential of elemental composition and isotopic signature of lead (207Pb/206Pb, 208Pb/206Pb and 204Pb/206Pb) and strontium (87Sr/86Sr) of wines from three Romanian vineyards, in order to highlight reliable markers for wine geographical origin. The ICP-MS method was used for the concentration determination for 30 elements (Ag, Al, As, Ba, Be, Bi, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, In, K, Li, Mg, Mn, Na, Ni, Pb, Rb, Se, Sr, Tl, V, U, Zn, Hg). In this study 10 wines (2 red and 8 white) obtained from ‘Merlot’, ‘Fetească neagră’, ‘Fetească albă’, ‘Fetească regală’, ‘Băbească gri’, ‘Șarba’, ‘Aligoté’, ‘Sauvignon blanc’, ‘Muscat Ottonel’, ‘Italian Riesling’ cultivars were investigated. The wine samples were obtained from micro-wine production under conditions of 2014, 2015, 2016 from Dealu Bujorului, Murfatlar and Ștefănești-Argeș vineyards. The high level of K (148.66±5.41-633.74±4.13 mg/L), Mg (88.23±0.84-131.66±3.42 mg/L), Ca (49.84±1.22-89.18±2.34) and Fe were observed in the wine samples analysed. Heavy metals like Hg, Pb, As and Cd (10.2-315 µg/L) were found below acceptable limits. Concentration of Na (1 mg/L), Cu (1 mg/L), As (0.2 mg/L), Cd (0.01 mg/L), Zn (5 mg/L) and Pb (0.15 mg/L) metals in analysed wine samples were under Maximum Permissible Limits (MPL), respectively as published by the Organization of Vine and Wine. The variation of the 207Pb/206Pb, 208Pb/206Pb, 204Pb/206Pb and 87Sr/86Sr ratio and K/Rb, Ca/Sr of the investigated wine clearly demonstrated that these variables are suitable traces for wine geographical origin determination. The proposed methodology allowed a 100% successful classification of wines according to the region of provenance
Vacancy clustering and diffusion in silicon: Kinetic lattice Monte Carlo simulations
Diffusion and clustering of lattice vacancies in silicon as a function of
temperature, concentration, and interaction range are investigated by Kinetic
Lattice Monte Carlo simulations. It is found that higher temperatures lead to
larger clusters with shorter lifetimes on average, which grow by attracting
free vacancies, while clusters at lower temperatures grow by aggregation of
smaller clusters. Long interaction ranges produce enhanced diffusivity and
fewer clusters. Greater vacancy concentrations lead to more clusters, with
fewer free vacancies, but the size of the clusters is largely independent of
concentration. Vacancy diffusivity is shown to obey power law behavior over
time, and the exponent of this law is shown to increase with concentration, at
fixed temperature, and decrease with temperature, at fixed concentration.Comment: 14 pages, 12 figures. To appear in Physical Review
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Automated Manufacturing of High Efficiency Modules: Final Subcontract Technical Status Report, 21 March 2005 - 31 August 2007
SunPower Corp. describes its research to develop low-cost, next-generation SunPower modules with 30-year warranties and at least 50% higher energy production per area relative to today's typical multicrystalline Si modules
Qualitative Assessment of the White Wine Varieties Grown in Dealu Bujorului Vineyard, Romania
Ecoclimatic conditions have a great influence on grapevine growth and development. Favourable conditions (solar radiation, temperature, humidity etc.) are important and have a positive effect on the growth and fruition. Critical conditions have negative influences resulting in low grape production and wine quality. The purpose of this research was to analyse the quality of wine obtained from eight grapevine varieties (four Romanian autochthonous varieties: ‘Feteasca regala’, ‘Feteasca alba’, ‘Babeasca gri’, ‘Sarba’, and four world-wide varieties: ‘Aligoté’, ‘Sauvignon Blanc’, ‘Muscat Ottonel’, and ‘Italian Riesling’). The wine samples were obtained from micro-wine production under local weather conditions of Dealu Bujoruluivineyard, Romania. The physico-chemical analysis of young wines showed that the highest alcohol content was recorded at the ‘Sauvignon blanc’ variety (14.35% vol.) followed by ‘Sarba’ (14.10% vol.). The highest level of acidity was registered to ‘Babeasca gri’ (5.90 g/L C4H6O6) and the lowest acidity in the ‘Muscat Ottonel’ wine (4.40 g/L C4H6O6). The pH values were between limits of 3.62 (‘Feteasca alba’) and 3.27 (‘Aligote’). In order to get a wider perspective about the wine quality, another 11 parameters were examined at these varieties, using spectrophotometric methods (acetic acid, potassium, calcium, free amino nitrogen, tartaric acid, copper, L-lactic acid, iron, L-malic acid, D-gluconic acid and glycerol). The results showed the suitability of ecoclimatic conditions and the proper growth and development of the tested varieties for obtaining wines withsuperiors quality
Comprobación de la presencia de probióticos en productos de uso oral
El objetivo principal de esta investigación fue comprobar la presencia de probióticos en productos de uso oral, comercializados en las diferentes farmacias ubicadas en la Colonia Médica de San Salvador, en las presentaciones de cápsulas, comprimidos masticables y sobres. Para la recolección de la muestra se utilizó una hoja de cotejo, que se aplicó para la identificación de los probióticos comercializados en cada una de las 16 farmacias en estudio, obteniendo un total de 24 muestras. Se realizó una descripción de cada uno de los productos con la normativa de etiquetado Reglamento Técnico Centroamericano RTCA 11.01.02:04 Productos Farmacéuticos. Etiquetado de Productos Farmacéuticos para uso Humano. Asà mismo un recuento en placa de bacterias ácido lácticas, también una identificación de los microrganismos tanto a nivel macroscópico como microscópico de las presentaciones de cápsulas, comprimidos masticables y sobres, se comparó con el estándar de referencia Lactobacillus rhamnosus.
Obteniéndose los siguientes resultados: para las muestras de cápsulas su crecimiento en placa fue de 1.5x103 UFC/mL, las de comprimidos masticables su crecimiento fue de 1.3x103 UFC/mL y las de sobres de 1.9x103 UFC/mL. En las tres presentaciones el crecimiento en placa fue inferior al rango que establece la Organización de las Naciones Unidas para la Agricultura y la Organización Mundial de la Salud (FAO/OMS) de 106 a 109 UFC. Para ser considerado como probiótico y ejercer un efecto positivo para el consumidor. Se recomiendan nuevas investigaciones con diferentes marcas y presentaciones de probióticos, para poder confirmar si contiene la cantidad que especifica en los productos. La investigación de llevó a cabo en el Laboratorio de MicrobiologÃa del Centro de Investigaciones y Desarrollo en Salud (CENSALUD) de la Universidad de El Salvador, durante el periodo de 2017 al 2019
Regularized fitted Q-iteration: application to planning
We consider planning in a Markovian decision problem, i.e., the problem of finding a good policy given access to a generative model of the environment. We propose to use fitted Q-iteration with penalized (or regularized) least-squares regression as the regression subroutine to address the problem of controlling model-complexity. The algorithm is presented in detail for the case when the function space is a reproducing kernel Hilbert space underlying a user-chosen kernel function. We derive bounds on the quality of the solution and argue that data-dependent penalties can lead to almost optimal performance. A simple example is used to illustrate the benefits of using a penalized procedure
Aggregation by exponential weighting, sharp PAC-Bayesian bounds and sparsity
We study the problem of aggregation under the squared loss in the model of
regression with deterministic design. We obtain sharp PAC-Bayesian risk bounds
for aggregates defined via exponential weights, under general assumptions on
the distribution of errors and on the functions to aggregate. We then apply
these results to derive sparsity oracle inequalities
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