Effect of cloud transits in a stand-alone solar photovoltaic water pumping system

This paper discusses the effects of cloud transit on a stand-alone direct solar photovoltaic water pumping system for irrigation and farms. In this way, its impact is studied, applying a possible classification based on its incidence and effects on the system. For this, the information provided by the data loggers of different photovoltaic installations has been analyzed and in turn compared with the data obtained in the reference installation. In addition, the Matlab-Simulink simulation model used is described. Different simulations have been developed to verify the basic characteristics of the proposed system. In this way, it is possible to check the advantages and drawbacks of the direct water pumping in irrigation applications. At the same time, the system parameters can be easily modified to meet the requirements of different water flow capacities. Also, the water hammer effect and the cavitation phenomenon in the water pump are described. Finally, the simulation results obtained as well as their conclusions are presented

Charges and fluxes in Maxwell theory on compact manifolds with boundary

We investigate the charges and fluxes that can occur in higher-order Abelian gauge theories defined on compact space-time manifolds with boundary. The boundary is necessary to supply a destination to the electric lines of force emanating from brane sources, thus allowing non-zero net electric charges, but it also introduces new types of electric and magnetic flux. The resulting structure of currents, charges, and fluxes is studied and expressed in the language of relative homology and de Rham cohomology and the corresponding abelian groups. These can be organised in terms of a pair of exact sequences related by the Poincar\'e-Lefschetz isomorphism and by a weaker flip symmetry exchanging the ends of the sequences. It is shown how all this structure is brought into play by the imposition of the appropriately generalised Maxwell's equations. The requirement that these equations be integrable restricts the world-volume of a permitted brane (assumed closed) to be homologous to a cycle on the boundary of space-time. All electric charges and magnetic fluxes are quantised and satisfy the Dirac quantisation condition. But through some boundary cycles there may be unquantised electric fluxes associated with quantised magnetic fluxes and so dyonic in nature.Comment: 28 pages, plain Te

Self Consistent 1/Nc1/N_c Expansion In The Presence Of Electroweak Interactions

In the conventional approach to the $1/N_c$ expansion, electroweak interactions are switched off and large $N_c$ QCD is treated in isolation. We study the self-consistency of taking the large $N_c$ limit in the presence of electroweak interaction. If the electroweak coupling constants are held constant, the large $N_c$ counting rules are violated by processes involving internal photon or weak boson lines. Anomaly cancellations, however, fix the ratio of electric charges of different fermions. This allows a self-consistent way to scale down the electronic charge $e$ in the large $N_c$ limit and hence restoring the validity of the large $N_c$ counting rules.Comment: 9 pages in REVTeX, no figure

Differential geometry construction of anomalies and topological invariants in various dimensions

In the model of extended non-Abelian tensor gauge fields we have found new metric-independent densities: the exact (2n+3)-forms and their secondary characteristics, the (2n+2)-forms as well as the exact 6n-forms and the corresponding secondary (6n-1)-forms. These forms are the analogs of the Pontryagin densities: the exact 2n-forms and Chern-Simons secondary characteristics, the (2n-1)-forms. The (2n+3)- and 6n-forms are gauge invariant densities, while the (2n+2)- and (6n-1)-forms transform non-trivially under gauge transformations, that we compare with the corresponding transformations of the Chern-Simons secondary characteristics. This construction allows to identify new potential gauge anomalies in various dimensions.Comment: 27 pages, references added, matches published versio

Direct CP, T and/or CPT violations in the K^0-\bar{K^0} system - Implications of the recent KTeV results on 2π2\pi decays -

The recent results on the CP violating parameters Re(e'/e) and \Delta\phi = \phi_{00}-\phi_{+-} reported by the KTeV Collaboration are analyzed with a view to constrain CP, T and CPT violations in a decay process. Combining with some relevant data compiled by the Particle Data Group, we find Re(e_2-e_0) = (0.85 +- 3.11)*10^{-4} and Im(e_2-e_0) = (3.2 +- 0.7)*10^{-4}, where Re(e_I) and Im(e_I) represent respectively CP/CPT and CP/T violations in decay of K^0 and \bar{K^0} into a 2\pi state with isospin I.Comment: 7 pages, No figure

Absolute magnitudes and phase coefficients of trans-Neptunian objects

Accurate measurements of diameters of trans-Neptunian objects (TNOs) are extremely difficult to obtain. Thermal modeling can provide good results, but accurate absolute magnitudes are needed to constrain the thermal models and derive diameters and geometric albedos. The absolute magnitude, H, is defined as the magnitude of the object reduced to unit helio-and geocentric distances and a zero solar phase angle and is determined using phase curves. Phase coefficients can also be obtained from phase curves. These are related to surface properties, but only few are known. Aims. Our objective is to measure accurate V-band absolute magnitudes and phase coefficients for a sample of TNOs, many of which have been observed and modeled within the program >TNOs are cool>, which is one of the Herschel Space Observatory key projects. Methods. We observed 56 objects using the V and R filters. These data, along with those available in the literature, were used to obtain phase curves and measure V-band absolute magnitudes and phase coefficients by assuming a linear trend of the phase curves and considering a magnitude variability that is due to the rotational light-curve. Results. We obtained 237 new magnitudes for the 56 objects, six of which were without previously reported measurements. Including the data from the literature, we report a total of 110 absolute magnitudes with their respective phase coefficients. The average value of H is 6.39, bracketed by a minimum of 14.60 and a maximum of-1.12. For the phase coefficients we report a median value of 0.10 mag per degree and a very large dispersion, ranging from-0.88 up to 1.35 mag per degree. © 2016 ESO.J.L.O. acknowledges support from the Spanish Mineco grant AYA-2011-30106-CO2-O1, from FEDER funds and from the Proyecto de Excelencia de la Junta de Andalucia, J.A. 2012-FQM1776. R.D. acknowledges the support of MINECO for his Ramon y Cajal ContractPeer Reviewe

Asymptotics and zeros of Sobolev orthogonal polynomials on unbounded supports

In this paper we present a survey about analytic properties of polynomials orthogonal with respect to a weighted Sobolev inner product such that the vector of measures has an unbounded support. In particular, we are focused in the study of the asymptotic behaviour of such polynomials as well as in the distribution of their zeros. Some open problems as well as some new directions for a future research are formulated.Comment: Changed content; 34 pages, 41 reference

Cancellation of Global Anomalies in Spontaneously Broken Gauge Theories

We discuss the generalization to global gauge anomalies of the familiar procedure for the cancellation of local gauge anomalies in effective theories of spontaneously broken symmetries. We illustrate this mechanism in a recently proposed six-dimensional extension of the standard model.Comment: 5 pages; v2: version to appear in Phys. Rev.

Nonanticommutative Deformation of N=4 SYM Theory: The Myers Effect and Vacuum States

We propose a deformation of ${\cal N}=4$ SYM theoery induced by nonanticommutative star product. The deformation introduces new bosonic terms which we identify with the corresponding Myers terms of a stack of D3-branes in the presence of a five-form RR flux. We take this as an indication that the deformed lagrangian describes D3-branes in such a background. The vacuum states of the theory are also examined. In a specific case where the U(1) part of the gauge field is nonvanishing the (anti)holomorphic transverse coordinates of the brane sit on a fuzzy two sphere. For a supersymmetric vacuum the antiholomorphic coordinates must necessarily commute. However, we also encounter non-supersymmetric vacua for which the antiholomorphic coordinates do not commute.Comment: 14 pages, minor changes, refs. adde

Constraints on Supersymmetric Theories from μ→e,γ\mu\to e,\gamma

In the absence of any additional assumption it is natural to conjecture that sizeable flavour-mixing mass entries, $\Delta m^2$, may appear in the mass matrices of the scalars of the MSSM, i.e. $\Delta m^2\sim O(m^2)$. This flavour violation can still be reconciled with the experiment if the gaugino mass, $M_{1/2}$, is large enough, leading to a {\em gaugino dominance} framework (i.e. $M_{1/2}^2\gg m^2$), which permits a remarkably model--independent analysis. We study this possibility focussing our attention on the $\mu\rightarrow e,\gamma$ decay. In this way we obtain very strong and general constraints, in particular \frac{M_{1/2}^2}{\Delta m}\simgt 34\ {\rm TeV}. On the other hand, we show that our analysis and results remain valid for values of $m^2$ much larger than $\Delta m^2$, namely for \frac{\Delta m^2}{m^2}\simgt \frac{m^2} {10\ {\rm TeV^2}}, thus extending enormously their scope of application. Finally, we discuss the implications for superstring scenarios.Comment: 12 pages, Latex, 5 figures as uuencoded compressed postscript files, uses psfig.st