Transient lateral photovoltaic effect in patterned metal-oxide-semiconductor films

The time dependent transient lateral photovoltaic effect has been studied with us time resolution and with chopping frequencies in the kHz range, in lithographically patterned 21 nm thick, 5, 10 and 20 um wide and 1500 um long Co lines grown over naturally passivated p-type Si (100). We have observed a nearly linear dependence of the transitorial response with the laser spot position. A transitorial response with a sign change in the laser-off stage has been corroborated by numerical simulations. A qualitative explanation suggests a modification of the drift-diffusion model by including the in uence of a local inductance. Our findings indicate that the microstructuring of position sensitive detectors could improve their space-time resolution.Comment: 4 pages, 4 figure

Hipertensión arterial : aspectos angiográficos del fondo ocular en el perro. Estudios de 24 casos

Se estudian los hallazgos clínicos, oftalmoscópicos y angiofluoresceinográficos del fondo ocular en 24 perros diagnosticados de hipertensión arterial sistémica. En 22 casos, la hipertensión arterial es secundaria a diferentes patologías previas y en dos casos la hipertensión arterial, es reconocida como idiopática o primaria. La angiofluoresceinografía, ha permitido identificar a las isquémias de coroides como las lesiones más precozmente detectadas en el fondo ocular, en el transcurso de la hipertensión arterial en el perro. Los cambios en la circulación de la coroides, preceden de forma sistemática a los ocurridos en la circulación retiniana. Las hemorragias retinianas descritas . clásicamente son valoradas en este estudio como un signo tardío en el proceso de hipertensión.Clinical, ophtalmologic and angiofluoresceinographic findings in ocular fundus are studied in 24 dogs which had been diagnosed as having systemic hypertension. In 22 cases, arterial hypertensions is secondary to different previous pathologies and, in two cases, arterial hypertension is recognized as idiopatic or primary. Angiofluoresceinography has allowed the identification of choroidal ischemias as those lesions most precociously detected in the ocular fundus in the course of arterial hypertension in dogs. Changes in choroidal circulation systematically precede those occuring in retinal circulation. Classically described retinal haemorrhages are assessed in this study as a late sing in the hypertension process

Domination by second countable spaces and Lindelöf Σ-property

AbstractGiven a space M, a family of sets A of a space X is ordered by M if A={AK:K is a compact subset of M} and K⊂L implies AK⊂AL. We study the class M of spaces which have compact covers ordered by a second countable space. We prove that a space Cp(X) belongs to M if and only if it is a Lindelöf Σ-space. Under MA(ω1), if X is compact and (X×X)\Δ has a compact cover ordered by a Polish space then X is metrizable; here Δ={(x,x):x∈X} is the diagonal of the space X. Besides, if X is a compact space of countable tightness and X2\Δ belongs to M then X is metrizable in ZFC.We also consider the class M⁎ of spaces X which have a compact cover F ordered by a second countable space with the additional property that, for every compact set P⊂X there exists F∈F with P⊂F. It is a ZFC result that if X is a compact space and (X×X)\Δ belongs to M⁎ then X is metrizable. We also establish that, under CH, if X is compact and Cp(X) belongs to M⁎ then X is countable

Measurable selectors and set-valued Pettis integral in non-separable Banach spaces

AbstractKuratowski and Ryll-Nardzewski's theorem about the existence of measurable selectors for multi-functions is one of the keystones for the study of set-valued integration; one of the drawbacks of this result is that separability is always required for the range space. In this paper we study Pettis integrability for multi-functions and we obtain a Kuratowski and Ryll-Nardzewski's type selection theorem without the requirement of separability for the range space. Being more precise, we show that any Pettis integrable multi-function F:Ω→cwk(X) defined in a complete finite measure space (Ω,Σ,μ) with values in the family cwk(X) of all non-empty convex weakly compact subsets of a general (non-necessarily separable) Banach space X always admits Pettis integrable selectors and that, moreover, for each A∈Σ the Pettis integral ∫AFdμ coincides with the closure of the set of integrals over A of all Pettis integrable selectors of F. As a consequence we prove that if X is reflexive then every scalarly measurable multi-function F:Ω→cwk(X) admits scalarly measurable selectors; the latter is also proved when (X∗,w∗) is angelic and has density character at most ω1. In each of these two situations the Pettis integrability of a multi-function F:Ω→cwk(X) is equivalent to the uniform integrability of the family {supx∗(F(⋅)):x∗∈BX∗}⊂RΩ. Results about norm-Borel measurable selectors for multi-functions satisfying stronger measurability properties but without the classical requirement of the range Banach space being separable are also obtained

Some topological cardinal inequalities for spaces Cp(X)

Using the index of Nagami we get new topological cardinal inequalities for spaces Cp(X). A particular case of Theorem 1 states that if L ⊆ Cp(X) is a Lindelöf Σ-space and the Nagami index Nag(X) of X is less or equal than the density d(L) of L (which holds for instance if X is a Lindelöf Σ-space), then (i) there exists a completely regular Hausdorff space Y such that Nag(Y ) Nag(X), L ⊂ Cp(Y ) and d(L) = d(Y ); (ii) Y admits a weaker completely regular Hausdorff topology τ such that w(Y , τ ) d(Y ) = d(L). This applies, among other things, to characterize analytic sets for the weak topology of any locally convex space E in a large class G of locally convex spaces that includes (DF)-spaces and (LF)-spaces. The latter yields a result of Cascales–Orihuela about weak metrizability of weakly compact sets in spaces from the class G.The research was supported for the second named author by National Center of Science, Poland, Grant No. N N201 605340 and for the third author by the project MTM2010-12374-E (complementary action) of the Spanish Ministry of Science and Innovation.Ferrando, JC.; Kakol, J.; López Pellicer, M.; Muñoz, M. (2013). Some topological cardinal inequalities for spaces Cp(X). Topology and its Applications. 160(10):1102-1107. https://doi.org/10.1016/j.topol.2013.04.024S110211071601

Note about Static D1-brane in I-brane Background

In this short note we will construct the static solutions on the world volume of D1-brane embedded in I-brane background.Comment: 20 pages, reference adde

Controlling shot noise in double-barrier magnetic tunnel junctions

We demonstrate that shot noise in Fe/MgO/Fe/MgO/Fe double-barrier magnetic tunnel junctions is determined by the relative magnetic configuration of the junction and also by the asymmetry of the barriers. The proposed theoretical model, based on sequential tunneling through the system and including spin relaxation, successfully accounts for the experimental observations for bias voltages below 0.5V, where the influence of quantum well states is negligible. A weak enhancement of conductance and shot noise, observed at some voltages (especially above 0.5V), indicates the formation of quantum well states in the middle magnetic layer. The observed results open up new perspectives for a reliable magnetic control of the most fundamental noise in spintronic structures.Comment: 8 pages, 4 figure

D6-branes and torsion

The D6-brane spectrum of type IIA vacua based on twisted tori and RR background fluxes is analyzed. In particular, we compute the torsion factors of the (co)homology groups H_n and describe the effect that they have on D6-brane physics. For instance, the fact that H_3 contains Z_N subgroups explains why RR tadpole conditions are affected by geometric fluxes. In addition, the presence of torsional (co)homology shows why some D6-brane moduli are lifted, and it suggests how the D-brane discretum appears in type IIA flux compactifications. Finally, we give a clear, geometrical understanding of the Freed-Witten anomaly in the present type IIA setup, and discuss its consequences for the construction of semi-realistic flux vacua.Comment: 35 pages, 1 figure. One reference adde

Thermodynamic analysis of unimer-micelle and sphere-to-rod micellar transitions of aqueous solutions of sodium dodecylbenzenesulfonate

Temperature dependence of specific conductivity of sodium dodecylbenzenesulfonate (NaDBS) aqueous solutions was analyzed. Two breaks on the plot appeared for all temperature, which suggest two micellar transitions. This has been corroborated by surface tension measurements. The first transition concentration occurs at the critical micelle concentration (CMC), whilst the second critical concentration (so-called transition micellar concentration, TMC) is due to a sphere-to-rod micelles transition. The dependence of CMC and TMC on the temperature allows the computation of the corresponding thermodynamic functions: Gibbs free energy, enthalpy and entropy changes. For the CMC, enthalpy and entropy increments were found that decrease with the temperature values. However, an anomalous behavior was obtained for the TMC, where both ΔS0 and ΔH0 values raised with the temperature increase. However, for both transitions, an (enthalpy + entropy) compensation is observed. These results will be compared with similar systems reported in the literature