Bicultural and Bilingual Americans: A Need for Understanding

published or submitted for publicatio

Tool expedites installation of BNC connectors

Tool is devised which holds BNC connector during installation and permits tightening nut without damaging connector

Qualitative study in Loop Quantum Cosmology

This work contains a detailed qualitative analysis, in General Relativity and in Loop Quantum Cosmology, of the dynamics in the associated phase space of a scalar field minimally coupled with gravity, whose potential mimics the dynamics of a perfect fluid with a linear Equation of State (EoS). Dealing with the orbits (solutions) of the system, we will see that there are analytic ones, which lead to the same dynamics as the perfect fluid, and our goal is to check their stability, depending on the value of the EoS parameter, i.e., to show whether the other orbits converge or diverge to these analytic solutions at early and late times.Comment: 12 pages, 7 figures. Version accepted for publication in CQ

Flexible temperature probe for biological systems

Probe is sufficiently flexible so that it can be worn comfortably for long periods of time, but relatively rigid to permit easy insertion. Body and electrical leads of small thermistor are imbedded in flexible fluorosilicone matrix contained in vinyl plastic tubing

Technique for detecting warm-hot intergalactic gas in quasar UV spectra

The ionizing spectral energy distribution of quasars exhibits a steepening of the distribution shortward of ~ 1200 A. The change of the power-law index from approximately -1 (near-UV) to -2 (far-UV) has so far been interpreted as being intrinsic to quasars. We consider the possibility that the steepening may result from a tenuous absorption component that is anticorrelated with large mass overdensities. UV sensitive satellites, whose detectors can extend down to 1000 A, can set a useful limit to such an absorption component through the search of a flux increase in the window 1050-1190 A (observer frame) with respect to an extrapolation of the continuum above 1230 A. Since the recent FUSE or HST-STIS data do not show any obvious discontinuity in this region, this effectively rules out the possibility that intergalactic HI absorption is very important, and it is concluded that most if not all of the steepening is intrinsic to quasars. A smaller flux discontinuity of order 1% cannot, however, be ruled out yet and would still be consistent with the warm-hot intergalactic component if it amounts to 30% of the baryonic mass, as predicted by some models of large scale structure formation, provided its temperature lies around 10^{5.5} K.Comment: 13 pages, 5 figures and 1 table, accepted for publication in Astrophysical Journal, typos corrected and correction for the faulty scaling of variable n_H^0 with redshif

Possible polarisation and spin dependent aspects of quantum gravity

We argue that quantum gravity theories that carry a Lie algebraic modification of the Poincare' and Heisenberg algebras inevitably provide inhomogeneities that may serve as seeds for cosmological structure formation. Furthermore, in this class of theories one must expect a strong polarisation and spin dependence of various quantum-gravity effects.Comment: Awarded an "honourable mention" in the 2007 Gravity Research Foundation Essay Competitio

Demixing can occur in binary hard-sphere mixtures with negative non-additivity

A binary fluid mixture of non-additive hard spheres characterized by a size ratio $\gamma=\sigma_2/\sigma_1<1$ and a non-additivity parameter $\Delta=2\sigma_{12}/(\sigma_1+\sigma_2)-1$ is considered in infinitely many dimensions. From the equation of state in the second virial approximation (which is exact in the limit $d\to\infty$) a demixing transition with a critical consolute point at a packing fraction scaling as $\eta\sim d 2^{-d}$ is found, even for slightly negative non-additivity, if $\Delta>-{1/8}(\ln\gamma)^2$. Arguments concerning the stability of the demixing with respect to freezing are provided.Comment: 4 pages, 2 figures; title changed; final paragraph added; to be published in PRE as a Rapid Communicatio

Quasar 3C 298: a test-case for meteoritic nanodiamond 3.5 µm emission

Aims. We calculate the dust emission expected at 3.43 and 3.53 µm if meteoritic (i.e. hydrogenated) nanodiamonds are responsible for most of the far-UV break observed in quasars. Methods. We integrate the UV flux that hydrogenated nanodiamonds must absorb to reproduce the far-UV break. Based on laboratory spectra of H-terminated diamond surfaces, we analyse the radiative energy budget and derive theoretically the IR emission profiles expected for possible C-H surface stretch modes of the diamonds. Results. Using as test case a spectrum of 3C 298 provided by the Spitzer Observatory, we do not find evidence of these emission bands. Conclusions. While diamonds without surface adsorbates remain a viable candidate for explaining the far-UV break observed in quasars, hydrogenated nanodiamonds appear to be ruled out, as they would give rise to IR emission bands, which have not been observed so far

Fourth virial coefficients of asymmetric nonadditive hard-disc mixtures

The fourth virial coefficient of asymmetric nonadditive binary mixtures of hard disks is computed with a standard Monte Carlo method. Wide ranges of size ratio ($0.05\leq q\leq 0.95$) and nonadditivity ($-0.5\leq \Delta\leq 0.5$) are covered. A comparison is made between the numerical results and those that follow from some theoretical developments. The possible use of these data in the derivation of new equations of state for these mixtures is illustrated by considering a rescaled virial expansion truncated to fourth order. The numerical results obtained using this equation of state are compared with Monte Carlo simulation data in the case of a size ratio $q=0.7$ and two nonadditivities $\Delta=\pm 0.2$.Comment: 9 pages, 7 figures; v2: section on equation of state added; tables moved to supplementary material (http://jcp.aip.org/resource/1/jcpsa6/v136/i18/p184505_s1#artObjSF

Caracterización y Tipificación De La Cadena Agroproductiva Del Cultivo De Maracuyá (passiflora edulis L) Pedernales, Manabí, Ecuador/Characterization and Typification of the Agroproductive Chain of Maracuya Cultivation (passiflora edulis L) Pedernales, M

La cadena agroproductiva de maracuyá (passiflora edulis L), se desarrolla en la costa ecuatoriana, destacando la calidad de producto en sus dos variedades amarilla y roja. El objetivo de esta investigación es realizar la caracterización y tipificación, analizando aspectos agroproductivos, socioeconómicos y comercio en las parroquias 10 de Agosto, Atahualpa y Cojimíes pertenecientes al cantón Pedernales, en cual cuenta con 266 productores de Maracuyá, abarcando una extensión de 532 hectáreas, la muestra constituye 20 fincas productoras, aplicando la metodología exploratoria, descriptiva y analítica, de evaluación insitú, obteniendo que el género masculino es el predominante en el manejo y responsabilidad de finca (100%), (90%) residen en la finca, cuentan con un nivel de estudios mayormente de escolaridad (75%), nivel sociorganizativo (15%) pertenecen alguna organización constituida legalmente, la tenencia de tierra representa un (25%) 1 - 5 ha, (25%) más de 26 ha, (20%) 6 - 10 ha, (15%) 11 - 15 ha y (15%) 16 - 25 ha, utilizan mano de obra adicional (40%), el tipo agricultura (90%) convencional, (10%) manejo orgánico, (55%), posee más de 3 cultivos en producción, ocupando el (75%) agua de rio, un (50%) realizan riego por surcos, la producción anual en Cojimíes representa (19 ha), con 27000 kg/ano, 10 de agosto (14 ha), con 24200 kg/año, Atahualpa (6 ha), con 5900 kg/año, el (74%) cultiva la variedad amarillo, (26%) variedad rojo morado, (100%) realizan actividades de pos cosecha el (85%) los ingresos mensuales provienen de agricultura (75%), (20%) crianza de animales; y (5%) del comercio. The agro-productive chain of passion fruit (passiflora edulis L), is developed on the Ecuadorian coast, highlighting the quality of the product in its two yellow and red varieties. The objective of this research is to characterize and typify, analyzing agroproductive, socioeconomic and trade aspects in the parishes 10 de Agosto, Atahualpa and Cojimíes belonging to the canton Pedernales, which has 266 Maracuyá producers, covering an area of 532 hectares, the sample constitutes 20 producing farms, applying the exploratory, descriptive and analytical methodology, of insitu evaluation, obtaining that the masculine gender is the predominant one in the management and responsibility of the farm (100%), (90%) they reside in the farm, they count With a level of education mostly of schooling (75%), socio-organizational level (15%) belong some legally constituted organization, land ownership represents one (25%) 1 - 5 ha, (25%) more than 26 ha, (20%) 6 - 10 ha, (15%) 11 - 15 ha and (15%) 16 - 25 ha, use additional labor (40%), the agriculture type (90%) conventional, (10%) management organic, (55%), owns more than 3 crops in production, occupying (75%) river water, one (50%) irrigate by furrows, the annual production in Cojimies represents (19 ha), with 27000 kg / year, August 10 (14 ha), with 24200 kg / year, Atahualpa (6 ha), with 5900 kg / year, (74%) cultivates the yellow variety, (26%) purple red variety, (100%) carry out post-harvest activities (85%) the monthly income comes from agriculture (75%), (20%) raising animals; and (5%) of commerce. Palabras clave: Caracterización, Tipificación, Cadena, Agro productiva, Maracuyá. Keywords: Characterization, Typification, chain, agro productive, passion fruit