Use of satellite images in the evaluation of farmlands

Remote sensing techniques in the evaluation of farmland in Mexico are discussed. Electronic analysis techniques and photointerpretation techniques are analyzed. Characteristics of the basic crops in Mexico as related to remote sensing are described

Trends in life cycle greenhouse gas emissions of future light duty electric vehicles

The majority of previous studies examining life cycle greenhouse gas (LCGHG) emissions of battery electric vehicles (BEVs) have focused on efficiency-oriented vehicle designs with limited battery capacities. However, two dominant trends in the US BEV market make these studies increasingly obsolete: sales show significant increases in battery capacity and attendant range and are increasingly dominated by large luxury or high-performance vehicles. In addition, an era of new use and ownership models may mean significant changes to vehicle utilization, and the carbon intensity of electricity is expected to decrease. Thus, the question is whether these trends significantly alter our expectations of future BEV LCGHG emissions. To answer this question, three archetypal vehicle designs for the year 2025 along with scenarios for increased range and different use models are simulated in an LCGHG model: an efficiency-oriented compact vehicle; a high performance luxury sedan; and a luxury sport utility vehicle. While production emissions are less than 10% of LCGHG emissions for today's gasoline vehicles, they account for about 40% for a BEV, and as much as two-thirds of a future BEV operated on a primarily renewable grid. Larger battery systems and low utilization do not outweigh expected reductions in emissions from electricity used for vehicle charging. These trends could be exacerbated by increasing BEV market shares for larger vehicles. However, larger battery systems could reduce per-mile emissions of BEVs in high mileage applications, like on-demand ride sharing or shared vehicle fleets, meaning that trends in use patterns may countervail those in BEV design

Cuando el traductor empieza a inventar: creaci\uf3n l\ue9xica en la versi\uf3n espa\uf1ola de Baudolino de Umberto Eco

In questo saggio si riflette sull'esperienza della traduzione dei dialettalismi e delle lingue inventate nella versione spagnola di "Baudolino" di Umberto Eco.Partendo dalla funzione umoristica e parodica e passando dagli esercizi letterari metasemantici, si descrive un meccanismo di apropriazione e resa traduttiva che richiama anche i meccanismi della traduzione medievale

Particle-vortex dynamics in noncommutative space

We study the problem of a charged particle in the presence of a uniform magnetic field plus a vortex in noncommutative planar space considering the two possible non-commutative extensions of the corresponding Hamiltonian, namely the ``fundamental'' and the ``antifundamental'' representations. Using a Fock space formalism we construct eigenfunctions and eigenvalues finding in each case half of the states existing in the ordinary space case. In the limit of $\theta \to 0$ we recover the two classes of states found in ordinary space, relevant for the study of anyon physics.Comment: 13 pages, no figures, plain LaTeX. References adde

Bethe-Salpeter equation for doubly heavy baryons in the covariant instantaneous approximation

In the heavy quark limit, a doubly heavy baryon is regarded as composed of a heavy diquark and a light quark. We establish the Bethe-Salpeter (BS) equations for the heavy diquarks and the doubly heavy baryons, respectively, to leading order in a $1/m_{Q}$ expansion. The BS equations are solved numerically under the covariant instantaneous approximation with the kernels containing scalar confinement and one-gluon-exchange terms. The masses for the heavy diquarks and the doubly heavy baryons are obtained and the non-leptonic decay widths for the doubly heavy baryons emitting a pseudo-scalar meson are calculated within the model.Comment: Corrections to the text, two references added, version accepted for publication in Physical Review

Energy efficiency in rice production systems of Purificacion (Tolima)

P?ginas 33-38Se determin? la eficiencia energ?tica de sistemas de producci?n de arroz en Purificaci?n (Tolima). La energ?a requerida para producir 1 kg de arroz fluctu? entre 314 kcal en un sistema org?nico orientado a mercados selectivos y 696 kcal en el sistema prevaleciente de altos insumos qu?micos. La relaci?n costo-beneficio no es significativamente diferente para estos dos sistemas, aunque se advierte que en el segundo se generan impactos tanto ambientales como sociales, que deben evaluarse en el contexto del departamento del Tolima. Desde el punto vista de la sostenibilidad, se advierte c?mo el determinismo econ?mico, proyectado en el ?mbito gremial y en la configuraci?n de unidades productivas arroceras, no restituye y a?n menos preserva atributos ambientales de los territorios donde la actividad se ha desarrollado.ABSTRACT. Energy efficiency in rice production systems was evaluated in Purificaci?n, Tolima (a province in Colombia). The energy required to produce 1 kg of rice ranged from 314 kcal in an organic rice system oriented to selective markets, to 696 kcal in the major system of higher chemical inputs. Benefit-cost relationship is not different for these two systems, although it is warned that in the second there are probably impacts both environmental and social that must be evaluated in the context of Tolima provinces. Form the sustainability perspective, some economics determinism is perceived with gremial and farm level projection, and in the setting of rice producing units, there is not restitution or even less preservation of environmental attributes from territories where rice activity has been developing

Temporal Correlations and Persistence in the Kinetic Ising Model: the Role of Temperature

We study the statistical properties of the sum $S_t=\int_{0}^{t}dt' \sigma_{t'}$, that is the difference of time spent positive or negative by the spin $\sigma_{t}$, located at a given site of a $D$-dimensional Ising model evolving under Glauber dynamics from a random initial configuration. We investigate the distribution of $S_{t}$ and the first-passage statistics (persistence) of this quantity. We discuss successively the three regimes of high temperature ($T>T_{c}$), criticality ($T=T_c$), and low temperature ($T<T_{c}$). We discuss in particular the question of the temperature dependence of the persistence exponent $\theta$, as well as that of the spectrum of exponents $\theta(x)$, in the low temperature phase. The probability that the temporal mean $S_t/t$ was always larger than the equilibrium magnetization is found to decay as $t^{-\theta-\frac12}$. This yields a numerical determination of the persistence exponent $\theta$ in the whole low temperature phase, in two dimensions, and above the roughening transition, in the low-temperature phase of the three-dimensional Ising model.Comment: 21 pages, 11 PostScript figures included (1 color figure