Alfonso Ramírez

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Electro-rotation can be used to determine the dielectric properties of cells, as well as to observe dynamic changes in both dielectric and morphological properties. Suspended biological cells and particles respond to alternating-field polarization by moving, deforming or rotating. While in linearly polarized alternating fields the particles are oriented(More)
General and approximated expressions are presented which allow the identification and quantification of errors in noise figure measurements that use the Y-factor method. This formulation is a generalization of that in /2/ to all measurement situations (in particular it is not necessary to include an input isolator). The formulas are utilized to determine(More)
For the modeling of erythrocyte rouleaux (linear cell aggregations), we propose an approximation procedure for the dipole moment in short cylinders, which contains the case of ellipsoidal bodies only as a first approximation. The method allows one to introduce corrections that are more representative for these particles. Depending on the number of(More)
Abstract Tin oxide (IV) or cassiterite obtained by the controlled precipitation method was characterized by different physical and chemical techniques such as TEM, surface area, XRD and RTP for the determination of the morphology, particle size distribution and reduction temperature of the system and then, a pure catalyst and doped with tin (Sn) and nickel(More)
Co3O4 particles were supported on a series of activated carbons (G60, CNR, RX3, and RB3). Incipient wetness method was used to prepare these catalysts. The effect of the structural and surface properties of the carbonaceous supports during oxidation of benzyl alcohol was evaluated. The synthetized catalysts were characterized via IR, TEM, TGA/MS, XRD, TPR,(More)
We present a multiwavelength study of the poor cluster RX J1117.4+0743 ([VMF 98] 097) at z=0.485, based on GMOS/Gemini South g ′ , r ′ photometry and spectroscopy, and XMM-Newton observations. We examine its nature and surroundings by analyzing the projected galaxy distribution, the galaxy velocity distribution, the weak-lensing mass reconstruction, and the(More)
Experimental populations were established with individuals with and without B chromosomes at different frequencies. Two species were used: the cross-pollinating Secale cereale, naturally carrying B chromosomes, and the self-pollinating S. vavilovii in which Bs were introduced artificially. The plants were allowed to fertilise by open pollination and the(More)
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