Next generation main battle tank. Part II: Converting old MBTS into unmanned MBTS (UMBT)

Modern MBTs (Main Battle Tank) are extremely expensive. Many outdated MBTs and other armored vehicles, often lacking the required armor protection, are still kept in depots. It is now convenient to upgrade them to optionally unmanned weapons by adding a humanoid driver, and a robotic arm as a loader. Sensors, an optional automatic driving system, a control and communication suite would complete the transformation. The main armament and secondary armament may be also changed or upgraded. The off-the-shelf huge electronic equipment can be installed wireless inside the hull. The old crew compartment may be spoiled of all the human related parts. Only the driver seat may be kept in order to leave the capability to remove the humanoid, robotized driver and reinstate the human one. This upgrade should also include a diagnostic system for the vehicle, the sensors and the additional systems to reduce the maintenance burden. An additional, specialized, lightweight armor suite should be focused to protect the mobilization system, the robots, the control and the communication system. This second part of the paper introduces a few options to convert the Leopard 1 MBT to an optionally piloted UMBT (Unmanned Main Battle Tank). A first, minimal step, is just the automation of the original tank. In a second step, the weight is reduced by installing a smaller 60mm cannon with a lighter, but more numerous ammunition storage. A third step increases the firepower by installing on the main turret an automated turret with a 12.7 or 30mm cannon with an optional additional 7.62 machinegun. It is also highly advisable to add an APU (Auxiliary Power Unit) and a battery to reduce IR (infrared) signature, improve main engine life and reduce maintenance

Mobility improvement of heavy tracked vehicles: The "pan" tank experience

This paper shows that the sinkage of the tracked vehicle is the most important parameter in its mobility. Power and fuel consumption follow cubic power law with sinkage. So the usual strategy to increase power is not the more convenient way to improve vehicle off road performance. The Ground Pressure (GP) is the critical parameter. Power requirement goes with the cubic power of sinkage. GP above 0.9 daN/cm2 should be avoided at all costs. The best way to obtain this result on an existing design is to increase track length. However it is easier to work on track width. The easiest modification is to add "Duckbill extensions" in the outer part of the shoe. This system was used on the Sherman Tank when additional armor was added. With modern technology it is perfectly possible to perform experimental tests with new shoes. This can be done by manufacturing prototypes of high stress nitrided steel shoes, usually with 300M high strength steel. Comparative fuel consumption is a good index of vehicle performance. Also wheel diameter and width can be increased to improve off-road performance. Specialized tracks for different terrains should also be designed. The gravity center should be kept slightly rearward. This attitude should not be excessive to keep the pressure value more even possible along the track. In any case the vehicle naturally assumes the backward inclination due to terrain compression. Another important improvement is the addition of computer controlled directional control to improve the accuracy of trajectories. This is particularly important for tracked vehicles where turning involves extremely high energy consumption

Fundamentación filosófica de la pedagogía argentina

Fil: Cassani, Juan E. . Universidad de Buenos Aire

La enseñanza gramatical

En el aprendizaje del idioma nacional, el conocimiento intuitivo prima en el ciclo primario, y el lógico en el secundario. La intuición pura o con mezcla de conceptos, de que habIa Crocce, hace aprender el manejo del idioma en los primeros grados y continúa actuando hasta la terminación de los estudios, y la forma conceptual aparece de lleno cuando se pasa al estudio teórico de la gramática. En el ciclo secundario se realiza el aprendizaje por conceptos, es decir, el aprendizaje de las relaciones de las cosas (Crocce), del lenguaje en este caso, y se cultiva la aptitud de pensar, razón que invocan los sostenedores de la gramática en el plan de estudios. La gramática figura entre las materias que peor aprenden los alumnos de nuestros colegios secundarios.Facultad de Humanidades y Ciencias de la Educació

Lpa1-5525 : a new lpa1 mutant isolated in a mutagenized population by a novel non-disrupting screening method

Phytic acid, or myo-inositol 1,2,3,4,5,6-hexakisphosphate, is the main storage form of phosphorus in plants. It is localized in seeds, deposited as mixed salts of mineral cations in protein storage vacuoles; during germination, it is hydrolyzed by phytases to make available P together with all the other cations needed for seed germination. When seeds are used as food or feed, phytic acid and the bound cations are poorly bioavailable for human and monogastric livestock due to their lack of phytase activity. Therefore, reducing the amount of phytic acid is one strategy in breeding programs aimed to improve the nutritional properties of major crops. In this work, we present data on the isolation of a new maize (Zea mays L.) low phytic acid 1 (lpa1) mutant allele obtained by transposon tagging mutagenesis with the Ac element. We describe the generation of the mutagenized population and the screening to isolate new lpa1 mutants. In particular, we developed a fast, cheap and non-disrupting screening method based on the different density of lpa1 seed compared to the wild type. This assay allowed the isolation of the lpa1-5525 mutant characterized by a new mutation in the lpa1 locus associated with a lower amount of phytic phosphorus in the seeds in comparison with the wild type

Gold nanoparticles on nanodiamond for nanophotonic applications

We present here some recent results of a research focused on the prepn. of detonation nanodiamond/Au nanoparticles hybrid materials. Two different exptl. routes are followed for the decoration of diamond nanoparticles by Au nanoparticles, that are in turn prepd. by an innovative electroless approach. Structure and morphol. at the nanoscale level of the Au-on-nanodiamond deposits have been deeply investigated by electron microscopy (FE-SEM, HR-TEM) and diffraction (XRD) techniques. Optical properties of these systems have been detd. by performing scattering and UV-Vis absorption measurements, and by comparing the exptl. data with simulated extinction spectra. The results highlighted very interesting plasmonic and scattering behaviors, mainly related to the high refractive index of diamond

de Sitter Supersymmetry Revisited

We present the basic $\mathcal{N} =1$ superconformal field theories in four-dimensional de Sitter space-time, namely the non-abelian super Yang-Mills theory and the chiral multiplet theory with gauge interactions or cubic superpotential. These theories have eight supercharges and are invariant under the full $SO(4,2)$ group of conformal symmetries, which includes the de Sitter isometry group $SO(4,1)$ as a subgroup. The theories are ghost-free and the anti-commutator $\sum_\alpha\{Q_\alpha, Q^{\alpha\dagger}\}$ is positive. SUSY Ward identities uniquely select the Bunch-Davies vacuum state. This vacuum state is invariant under superconformal transformations, despite the fact that de Sitter space has non-zero Hawking temperature. The $\mathcal{N}=1$ theories are classically invariant under the $SU(2,2|1)$ superconformal group, but this symmetry is broken by radiative corrections. However, no such difficulty is expected in the $\mathcal{N}=4$ theory, which is presented in appendix B.Comment: 21 pages, 2 figure

Comportamiento de "Pinus Taeda" L. y de "Pinus caribaea" Morelet en el Delta del Paraná

El estudio practicado en pequeñas plantaciones que con carácter de ensayo tiene la «Celulosa Argentina S. A.» en el Delta inferior entrerriano muestra un buen comportamiento para Pinus Taeda y P. caribaea, no así en el caso del Pinus radiata. Tolerantes a los suelos húmedos, hasta los 10 años no presentan síntomas de declinación, como en P. radiata. De las dos especies Pinus Taeda prospera en mejores condiciones ofreciendo diámetros y alturas promedios superiores a P. caribaea. En el orden citado miden 20 y 19,8 cm con corteza y 18,6 y 16,9 sin corteza, diámetros tomados a la altura del pecho; las alturas totales son respectivamente 14,80 y 12,90 metros. Este mayor crecimiento da como resultado una producción por hectárea de 291 y 199 metros cúbicos para Pinus Taeda y P. caribaea respectivamente a los 10 años de edad, considerando el fuste sin corteza. Esta es de 7 mm de espesor en Pinus Taeda y 14 mm en el P. caribaea. El rendimiento en metros cuadrados de tablas aserradas de 25,4 mm de espesor utilizando sierra circular de 6,25 mm de espesor sería de 3.082 y 1.892 para Pinus Taeda y P. caribaea respectivamente, considerando sólo como aserrable los rollizos hasta 15 cm de diámetro, sin corteza en el extremo más fino. La distancia de plantación de 2 x 3 m no se considera correcta aconsejándose en principio densidad de 2.500 a 3.000 árboles por hectárea. El desrame natural observado fué muy bajo debido a la causa apuntada pero aun con densidades mayores éste debe ayudarse practicándolo anticipadamente en ramas jóvenes o brotes tiernos para la obtención de madera de mejor calidad. Se observó en Pinus caribaea un flujo apreciable en resina y en ambas especies un comienzo de fructificación aunque no se apreciaron semillas viables en los conos recogidos. Si bien este estudio está referido a un terreno protegido en su perímetro por un terraplén de 1,20 a 1,50 m de alto, los datos recogidos en lo que respecta a tolerancia para suelos inundados en su área de dispersión natural, permiten suponer que puede prosperar en las islas no endicadas, en las que se hayan efectuado la sistematización común en el Delta para favorecer el rápido drenaje de las aguas que cubren el suelo durante los «repuntes» periódicos.Facultad de Ciencias Agrarias y Forestale

Nonlinear Klein-Gordon-Maxwell systems with Neumann boundary conditions on a Riemannian manifold with boundary

Let (M,g) be a smooth compact, n dimensional Riemannian manifold, n=3,4 with smooth n-1 dimensional boundary. We search the positive solutions of the singularly perturbed Klein Gordon Maxwell Proca system with homogeneous Neumann boundary conditions or for the singularly perturbed Klein Gordon Maxwell system with mixed Dirichlet Neumann homogeneous boundary conditions. We prove that stable critical points of the mean curvature of the boundary generates solutions when the perturbation parameter is sufficiently small.Comment: arXiv admin note: text overlap with arXiv:1410.884