Coherent transport in extremely underdoped Nd1.2Ba1.8Cu3Oz nanostructures

Proximity-effect and resistance magneto-fluctuations measurements in submicron Nd1.2Ba1.8Cu3Oz (NBCO) nano-loops are reported to investigate coherent charge transport in the non-superconducting state. We find an unexpected inhibition of cooper pair transport, and a destruction of the induced superconductivity, by lowering the temperature from 6K to 250mK. This effect is accompanied by a significant change in the conductance-voltage characteristics and in the zero bias conductance response to the magnetic field pointing to the activation of a strong pair breaking mechanism at lower temperature. The data are discussed in the framework of mesoscopic effects specific to superconducting nanostructures, proximity effect and high temperature superconductivity.Comment: to appear on new journal of Physic

Little-Parks effect in single YBaCuO sub-micron rings

The properties of single submicron high-temperature superconductor (HTS) rings are investigated. The Little-Parks effect is observed and is accompanied by an anomalous behavior of the magnetic dependence of the resistance, which we ascribe to non-uniform vorticity (superfluid angular momentum) within the ring arms. This effect is linked to the peculiar HTS-relationship between the values of the coherence length and the London penetration depth.Comment: 14 pages, 3 figure

Genetic variability of families of half-sibling of ecuadorian creole melon Cucumis melo var. dudaim (L.) Naudin

El melón, se cultiva en climas templados y cálidos de todo el mundo; no obstante, la información sobre la variabilidad genética del melón criollo ecuatoriano es limitada, para iniciar programas de mejoramiento. El objetivo de esta investigación fue evaluar características de producción y de calidad del fruto, en 20 familias de medios hermanos, seleccionadas de melón criollo ecuatoriano. El estudio, se realizó en el cantón Palenque, Ecuador. La semilla de las 20 familias seleccionadas, se dispusieron en bloques completos al azar, con tres repeticiones. Las diferencias entre familias fueron significativas para siete caracteres. La familia 73 presentó mayor peso, diámetro, longitud, espesor, cavidad del fruto y producción por hectárea; la familia 7 obtuvo el mayor promedio para grosor de corteza, sólidos solubles y firmeza de pulpa, mientras en la familia 196, se destacó la acidez de pulpa. Existen asociaciones fenotípicas altamente significativas entre peso de fruto con diámetro, longitud, espesor de pulpa, cavidad de fruto y producción por hectárea, en donde los coeficientes de variación genotípica fueron mayores que los coeficientes de variación ambiental. Las estimaciones de heredabilidad en sentido amplio fueron de magnitud alta (>60%), para los 10 caracteres evaluados y la magnitud del progreso genético esperado fue alta (>20%), para peso del fruto, producción por hectárea y grosor de corteza; moderada, para cavidad del fruto y sólidos totales. La selección para melones variedad dudaim, se debe centrar en contenido de sólidos solubles y peso del fruto, que presentó una alta correlación con el rendimiento.Melon is an important horticultural crop in temperate and warm climates around the world; however, information on the genetic variability of ecuadorian creole melon is limited to initiate breeding programs. The objective of this research was to evaluate 20 families of half-sibling of ecuadorian creole melon by characteristics of production and fruit quality. The study was carried out in Palenque canton, Ecuador. The seed of the 20 families selected was arranged in complete blocks at random with three repetitions. The differences between families were signifi cant for seven characters. Family 73 had greater weight, diameter, length, thickness, fruit cavity, and production per hectare, family 7 had the highest average for bark thickness, soluble solids and pulp fi rmness; the 196 family for pulp acidity. There are highly signifi cant phenotypic associations between fruit weight with diameter, length, pulp thickness, fruit cavity and production per hectare. The coeffi cients of genotypic variation were greater than the coeffi cients of environmental variation. The estimates of heritability in the broad sense were of high magnitude (>60%) for the 10 characters evaluated and the magnitude of the expected genetic progress was high (>20%) for fruit weight, production per hectare, and bark thickness; moderate for fruit cavity and total solids; the selection for melons of the dudaim variety should focus on soluble solids content and fruit weight that showed a high correlation with yield

In_(0.75)Ga_(0.25)As on GaAs submicron rings and their application for coherent nanoelectronic devices

Electron-phase modulation in magnetic and electric fields will be presented in In_(0.75)Ga_(0.25)As Aharonov-Bohm (AB) rings. The zero Schottky barrier of this material made it possible to nanofabricate devices with radii down to below 200 nm without carrier depletion. We shall present a fabrication scheme based on wet and dry etching that yielded excellent reproducibility, very high contrast of the oscillations and good electrical gating. The operation of these structures is compatible with closed-cycle refrigeration and suggests that this process can yield coherent electronic circuits that do not require cryogenic liquids. The InGaAs/AlInAs heterostructure was grown by MBE on a GaAs substrate [1], and in light of the large effective g-factor and the absence of the Schottky barrier is a material system of interest for the investigation of spin-related effects [2-4]} and the realization of hybrid superconductor/semiconductor devices [5].Comment: 7 pages, 4 figures, to appear in Physica

Design, optimization and experimental characterization of RF injectors for high brightness electron beams and plasma acceleration

In this article, we share our experience related to the new photo-injector commissioning at the SPARC\_LAB test facility. The new photo-injector was installed into an existing machine and our goal was not only to improve the final beam parameters themselves but to improve the machine handling in day-to-day operations as well. Thus, besides the pure beam characterization, this article contains information about the improvements, that were introduced into the new photo-injector design from the machine maintenance point of view, and the benefits, that we gained by using the new technique to assemble the gun itself

Dark Tourism: Tourist Motivations at The Site of Grief in Liberty Shrine, Cebu, Philippines

There is a marked rise in the development of outrage and demise-related tourist spots, destinations, and places of interest that provide potential information, insight, and recreation, enticing individuals eager to consume natural and commoditized death. The Liberty Shrine in Mactan, Cebu, Philippines, is an example of dark tourism because this spot is a commemorative marker that gives people an insight that the place was where Chieftain Lapu-Lapu killed Ferdinand Magellan during the battle in Mactan that, makes the latter the first Filipino to have deterred European belligerence. The study aimed to identify tourist motivations at the grief site in Liberty Shrine, located at Mactan, Cebu, Philippines. The study utilized the descriptive survey method validated through in-depth interviews, documentary analysis, and historical analysis. Using Stone's (2006) Dark Tourism theory, data were obtained from one hundred respondents (100), including government employees, residents, and tourists. Results revealed that visitor motivations at the grief site included location, education, motive, and promotion. It concluded that although location and education were rated Very Effective, motive and promotion were rated Effective only. The study recommended that the site management conduct systematic research and various promotional strategies, focusing on those that have proven more effective

The impact of β 2 adrenergic receptor polymorphisms on the outcomes in cardiovascular diseases

Cardiovascular diseases (CVD) include a heterogeneous group of multifactorial conditions and represent the major health problem in the western society. Many studies have evidenced that inter-individual variability affects the prognosis and the response to pharmacological treatment in patients with CVD. The identification of genetic markers to select patients more susceptible to develop cardiovascular complications has a therapeutic interest for undertaking individualized therapeutic approach. The sympathetic nervous system acts through adrenergic receptor subtypes and plays a key role in the development and prognosis of CVD. In particular, β-2 adrenergic receptors (β2AR), expressed in a wide variety of tissues, are critical regulators of cardiac output, peripheral vascular resistance and metabolism. Several variations with multiple single-nucleotide polymorphisms have been identified in β2AR gene. There are 3 common β2AR polymorphisms characterized in more detail for their influence on functional receptor activity. In particular, the changing an arginine for a glycine at position 16 of the receptor protein (Arg16Gly) is associated with increased agonist-induced down-regulation; the substitution of glutamine with glutamic acid at position 27 (Gln27Glu) leads to resistance to down-regulation; the substitution of threonine with isoleucine (Thr164Ile) at position 164 causes receptor uncoupling from the G protein. Many studies have indicated the association of β2AR polymorphisms with various cardiovascular and metabolic diseases and have contributed to indicate the β2AR gene variants an appropriate target for investigating possible links between receptor polymorphisms, drug responses and susceptibility to CVD. However, the reports on the association of β2AR polymorphisms with clinical outcomes of CVD have been contradictory. In this review, we will illustrate the effects of β2ARs genetic variability on the management of CVD

Kinetic of biogas production from oil palm empty fruit bunches

The production process of oil from Elaeis guineensis palm produces an organic residual. Oil palm empty fruit bunches (OPEFB) are one of the main waste products, representing 7%. Up to now, OPEFB aren't totally used, being an environmental problem. In this paper, the employment of OPEFB pretreated with NaOH is studied as a raw material for biogas production. The pretreatment time (PT) of theOPEFB influences directly on biogas production achieving conversions of volatile solids to biogas of 96% for PT=60 min and 29 days of reaction. Biogas production is adjusted to a first order kinetic law, with kinetic constants for the generation of CH4 (0,108 d-1) and CO2(0,107 d-1) at the reactor operating temperature (55°C). Finally, a general model is obtained to estimate volatile solids conversion to biogas as a function of pretreatment time and of the residence time inside the reactor.La producción de aceite de la palma Elaeis guineensis aporta residuales orgánicos como los racimos sin frutos (RSF) que representan un 7%. Actualmente los RSF no se aprovechan en su totalidad constituyendo un problema medioambiental. Se estudia el empleo de RSFpretratados con NaOH para la producción de biogás. El tiempo de pretratamiento (TP) de los RSF influye directamente sobre la cantidad de biogás producida logrando conversiones de sólidos volátiles a biogás de 96%, para TP = 60 min y 29 días de reacción. La producción de biogás se ajusta a una ley cinética de orden 1 obteniéndose las constantes cinéticas de la generación de CH4 (0,108 d-1) y CO2 (0,107 d-1) a la temperatura de operación del reactor (55°C). Se presenta un modelo generalizador que permite estimar la conversión de sólidos volátiles a biogás en función del tiempo de pretratamiento y del tiempo de permanencia en el reactor