El crecimiento de la producción científica está asociado al aumento de la inversión en ciencia y tecnología que realiza un país. La decisión de aumentar la inversión en ciencia forma parte de una decisión estratégica de desarrollar algún segmento de su aparato productivo. Se identifican tres patrones de desarrollo productivo. Un patrón está asociado a la producción de servicios en el área de la salud, un segundo patrón a la producción de productos altamente tecnológicos y el tercero está asociado al segundo patrón, junto con la química y las ingenierías. En este artículo presentamos la importancia de la física en la inversión de ciencia y tecnología bajo los tres esquemas descritos.

In this work, we analyze the electron transport in rectangular conductors in which we insert a nanopore which restrict the carrier flux. Actually, to setup molecules at middle of the nanopore, we observe resonances and anti-resonances in the transmission coefficient when the molecule orientation is parallel or perpendicular to carrier flux. In our case, the conductor is described by a tight binding approximation, the transmission coefficients through the system are calculated by Landauer formula considering a ballistic regime at low temperatures and the out of equilibrium Green functions to permit us calculate the coupling of the leads with conductor including the nanopore and the molecules, recursively. The presence of the molecules at middle of the nanopore are described, also, by the tight binding approximation.

We analyze the electronic transport in a graphene nanodevice with a rectangular nanopore in the presence of different configurations molecules at the nanopore’s center. The behaviour of the electrons is described by the tight-binding method and the transport in the ballistic regime by the Landauer’s formula, where the electrical conductance is given by the transmission coefficient, which is determined using the non-equilibrium Green’s functions. The nanodevice is connected to two graphene semi-infinite contacts. The results show that the presence of molecules at the nanopore center produce resonance (antiresonance) in the profile of the transmission coeficient difference between nanodevice with and without molecule at the nanopore center. These resonances (antiresonances) are due to the coupling of the molecule discrete states and the continuum states of nanodevice also called as t...

Oslo is a software allow to design optical systems in an interactive graphical environment using an optical elements set such as mirrors, lens, prisms, diafragms, pupils, showing the parameters details of each element which are added succesively to finally obtain the optical system with expected parameters we want to build. In this paper, we compare the theoretical models and OSLO results for the design of an achromatic len, an parallel plates prism and achromatic len with the Scheimpflug condition for validating purposes of the OSLO as a computer didactic tool for teaching geometric and paraxial optics.

In some devices, the functionning of them is based in the interband transitions in which the electrons and holes recombine emitting photons in the visible and infrared regions. In a superlattice is formed several minibands separated by minigaps, between them may be induced intraband transitions that emitting photons in the infrarred and microwaves regions. In the present work, we develop a model that permit us calculate the probabilities per unit time of such transitions and that permit us identify the transitions used in a quantum cascade laser. We simulate two superlattice type, one with a 100 Å quantum well and the second with two dimerized quantum wells of 100 and 150 Å. In the first case, we clearly identify three cascade transitions and, in the second, we do not observe the possibility of a quantum cascade transition. But, we find a possible evidence of the competition of entangl...

In the last years of economical crisis, we are considering to design and build scientific equipment for learning and research purpose, using electronic devices with open code which have developed in the last years precisely by the crisis. such as the Arduino and the Raspberry Pi, which offers at low cost in the local market.In the present work, we report the beginning of this adventure, with the implementation of a relatively simple circuit such as the Chua’s circuit, broadly know to present a chaotic behaviour by the non-linearity formed by two linear behaviour in an interval voltages.

The visualization of areas, volumes, topologies and perspectives objects that stay in our environment are making by ours eyes and brain, which have a long evolution through millions years ago. This ensemble between eyes and brain must be simulated by technology in which an artificial intelligence entity take an autonomous decision based on data information acquired by sensors and computer vision. The fidelity of acquired information from the environment is the fundamental key for a good decision. In this context, the cameras and optical lens miniaturization involves distortions which modify the acquired images of areas, volumes, topologies and perspectives objects. In the present work, we make a calibration process of optical cameras which involves radial and tangential distortions, and using OpenCV libraries we calculate the intrinsics and extrinsics parameters which permit us to obtain...

In the last decade the multicore processors had emerged with the comeback of the symmetric multiprocessing (SMP) after a long decade in which the based OpenMPI clusters had dominated the high performace processing world. Actually, we have in the market 2, 4 and 6 multicore processors; the Cell BE processors with a Power Processor Element (PPE) and 8 vectorial processors called Synergistic Processor Element (SPE), and graphics processors which have from 48 to 448 cores dedicated to numerical tasks. In the present work, we show our experience in the interaction with these processors, discussing the programming techniques and the future possibilities for making low cost numerical tasks.

In the present work we realize a systematic study of the optical properties of transition metal dichalcogenides using time dependent density functional theory for the determination of excited states of conduction band considering the electron density as a time dependent functional and temporarily affect the screening Coulomb potential which is used in Dyson equation for electric susceptibility determination. We calculate the real and imaginary parts of dielectric function which permit us to observe the absorption coefficient and the plasmon formation for electromagnetic radiation photons from the infrared (25 meV) to ultraviolet (30 eV) range. And we found that the imaginary parts of zz component of the 2D systems have not absorption peaks, meanwhile, the xx, yy and zz components of the 2D systems have not shown plasma frequencies.

Since the experimental obtention of graphenen in 2004, the two dimensional crystalline systems was a study subject of strong analysis from theoretical and experimental point of view. The analytical methods goes from tight binding, Dirac equations for K and K’ points to functional density theories. The present work is an initial study of the electronic structure and the phonon frequencies spectra of 2D crystalline systems using functional density theory. We use the Exciting Fortran 90 code and GPAW Python code. The results of electronic structure for some 2D lattices are shown and also the graphene phonon frequencies spectra.

The graphene, since 2004, had show some exceptional mechanical, thermal and electronic properties in se- veral configurations such as optical modulators, transistors, gas detectors, electrocromic devices, electrodes, thermal dissipaters and integrated circuits. There is an inconvenient in the atom by atom manipulation for obtain the specific properties for each function in each proposed device. We account between them, the disorder in the graphene structure and the intercalation of impurities in the hexagonal structure and the imperfections of the substrate that incorporate ripples in the graphene structure. Nevertheless, these do not modify the cones of the valence and conduction bands. The Dirac point remains. Other options has been suggested to induce a gap between the K and K′ symmetry points where lay the Dirac points in which converge the two charge carrier cones, electrons and h...