71 research outputs found

    Investigación sobre la composición química, minerales y ácidos grasos de dos cultivares de almendra cultivados como orgánico y convencional en el sudeste de Turquía

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    Organic farming is a human and environment friendly production system that is based on soil fertility and food safety without using chemical fertilizers and pesticides in production, aiming to re-establish the deteriorated ecological balance as a result of harmful production practices. Organic products attract the interest of consumers as they are strongly perceived as healthier products compared to conventional food. This study aimed to determine the differences in chemical, mineral, and fatty acid characteristics between conventionally and organically cultivated Ferragnes and Ferraduel almond cultivars. When conventional and organic almonds were evaluated in terms of fatty acids, proximate compositions, and minerals, crude oil and Mg were statistically insignificant, while Cu was significant (P < 0.05) and all others were quite significant (P < 0.001). Total sugar was higher in organic samples compared to conventional samples in both cultivars. The crude oil and linoleic acid (12.93% for Ferragnes and 14.99% for Ferraduel) were higher in conventional samples but oleic acid (78.9% for Ferragnes and 81.08% for Ferraduel) was higher in organic samples. In addition, organic samples contained higher Mg and Fe but lower P, K, Ca, Na, Zn, Mn and Cu when compared with conventional samples. The results indicate that conventionally cultivated almonds present higher mineral content and lower fatty acid value compared to organically cultivated almonds.La agricultura orgánica es un sistema de producción amigable con el ser humano y el medio ambiente, basado en la fertilidad del suelo y la seguridad alimentaria. Este sistema suele prescindir del uso de fertilizantes químicos y pesticidas en la producción, con el objetivo de prefijar el equilibrio ecológico previamente destruido como resultado natural de prácticas de producción incorrectas. Los productos orgánicos están atrayendo cada vez más el interés de los consumidores ya que se perciben como productos más saludables en comparación con los alimentos convencionales. Este estudio tenía como objetivo determinar las diferencias en las características químicas, minerales y ácidos grasos existentes entre los cultivares de almendra de Ferragnes y de Ferraduel, cultivados tanto convencionalmente como orgánicamente. Cuando se evaluaron las almendras convencionales y las orgánicas en términos de ácidos grasos, composiciones proximal y minerales, el aceite crudo y el Mg fueron estadísticamente insignificantes, mientras que los valores de Cu fue significativo (P < 0.05) y todos los demás fueron bastante significativos (P < 0.001). El azúcar total fue mayor en muestras orgánicas en comparación con muestras convencionales en ambos cultivares. El aceite crudo y el ácido linoleico (12.93% para Ferragnes y 14.99% para Ferraduel) fue mayor en muestras convencionales, pero el ácido oleico (78.9% para Ferragnes y 81.08% para Ferraduel) fue mayor en muestras orgánicas. Además, las muestras orgánicas contenían mayor Mg y Fe pero menor P, K, Ca, Na, Zn, Mn y Cu cuando se compararon con las muestras convencionales. Los resultados indican que las almendras convencionales presentan mayor contenido mineral y menor valor de ácidos grasos en comparación con las cultivadas orgánicamente

    Coarsening in Solid-liquid Mixtures: Overview of Experiments on Shuttle and ISS

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    The microgravity environment on the Shuttle and the International Space Station (ISS) provides the ideal condition to perform experiments on Coarsening in Solid-Liquid Mixtures (CSLM) as deleterious effects such as particle sedimentation and buoyancy-induced convection are suppressed. For an ideal system such as Lead-Tin in which all the thermophysical properties are known, the initial condition in microgravity of randomly dispersed particles with local clustering of solid Tin in eutectic liquid Lead-Tin matrix, permitted kinetic studies of competitive particle growth for a range of volume fractions. Verification that the quenching phase of the experiment had negligible effect of the spatial distribution of particles is shown through the computational solution of the dynamical equations of motion, thus insuring quench-free effects from the coarsened microstructure measurements. The low volume fraction experiments conducted on the Shuttle showed agreement with transient Ostwald ripening theory, and the steady-state requirement of LSW theory was not achieved. More recent experiments conducted on ISS with higher volume fractions have achieved steady-state condition and show that the kinetics follows the classical diffusion limited particle coarsening prediction and the measured 3D particle size distribution becomes broader as predicted from theory

    Development of a thulium (Tm:YAP) laser system for brain tissue ablation

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    In this study, a thulium (Tm:YAP) laser system was developed for brain surgery applications. As the Tm:YAP laser is a continuous-wave laser delivered via silica fibers, it would have great potential for stereotaxic neurosurgery with highest local absorption in the IR region. The laser system developed in this study allowed the user to set the power level, exposure time, and modulation parameters (pulse width and on-off cycles). The Tm:YAP laser beam (200-600 mW, 69-208 W/cm 2) was delivered from a distance of 2 mm to cortical and subcortical regions of ex-vivo Wistar rat brain tissue samples via a 200-μm-core optical fiber. The system performance, dosimetry study, and ablation characteristics of the Tm:YAP laser were tested at different power levels by maximizing the therapeutic effects and minimizing unwanted thermal side-effects. The coagulation and ablation diameters were measured under microscope. The maximum ablation efficiency (100 × ablation diameter/coagulation diameter) was obtained when the Tm:YAP laser system was operated at 200 mW for 10 s. At this laser dose, the ablation efficiency was found to be 71.4% and 58.7% for cortical and subcortical regions, respectively. The fiber-coupled Tm:YAP laser system in hence proposed for the delivery of photothermal therapies in medical applications. © 2011 Springer-Verlag London Ltd

    Influence of particle size and feed rate on coal cleaning in a dry separator

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    This research is concerned with the effects of particle size distribution and feed rate of feed on the coal cleaning performance of table type air separator. In tests, the lignite and hard coal samples from Mugla and Zonguldak districts in Turkey were used. The samples were tested in three different size distributions such as –38 + 6 mm, –19 + 6 mm and –9.5 + 6 mm. The effect of particle size was investigated together with the feed rate 2 Mg/(hm2), 1.68 Mg/(hm2) and 1.32 Mg/(hm2) and very important physical parameters of table type air separator such as, riffle height, table slope and table frequency. Results were analyzed by using the Tromp curve for indicating the effects in detail. Consequently, the results revealed that the particle size had remarkable effect on separation efficiency. The separation efficiency was, however, inversely affected as the particle size distribution became finer, and the best results were obtained in particle size distribution was –38 + 25 mm in both sample tested. The Ep value was 0.11 for the hard coal samples while it was 0.13 for the lignite samples

    Advances in the Automated Segmentation of 3-D Microstructures

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