731 research outputs found

    Interconnect fatigue design for terrestrial photovoltaic modules

    Get PDF
    The results of comprehensive investigation of interconnect fatigue that has led to the definition of useful reliability-design and life-prediction algorithms are presented. Experimental data indicate that the classical strain-cycle (fatigue) curve for the interconnect material is a good model of mean interconnect fatigue performance, but it fails to account for the broad statistical scatter, which is critical to reliability prediction. To fill this shortcoming the classical fatigue curve is combined with experimental cumulative interconnect failure rate data to yield statistical fatigue curves (having failure probability as a parameter) which enable (1) the prediction of cumulative interconnect failures during the design life of an array field, and (2) the unambiguous--ie., quantitative--interpretation of data from field-service qualification (accelerated thermal cycling) tests. Optimal interconnect cost-reliability design algorithms are derived based on minimizing the cost of energy over the design life of the array field

    The Chandra Dust Scattering Halo of Galactic Center transient Swift J174540.7-290015

    Get PDF
    We report the detection of a dust scattering halo around a recently discovered X-ray transient, Swift J174540.7-290015, which in early February of 2016 underwent one of the brightest outbursts (F_X ~ 5e-10 erg/cm^2/s) observed from a compact object in the Galactic Center field. We analyze four Chandra images that were taken as follow-up observations to Swift discoveries of new Galactic Center transients. After adjusting our spectral extraction for the effects of detector pileup, we construct a point spread function for each observation and compare it to the GC field before the outburst. We find residual surface brightness around Swift J174540.7-290015, which has a shape and temporal evolution consistent with the behavior expected from X-rays scattered by foreground dust. We examine the spectral properties of the source, which shows evidence that the object transitioned from a soft to hard spectral state as it faded below L_X ~ 1e36 erg/s. This behavior is consistent with the hypothesis that the object is a low mass X-ray binary in the Galactic Center.Comment: Accepted for publication in Ap

    Thermodynamics predicts how confinement modifies hard-sphere dynamics

    Full text link
    We study how confining the equilibrium hard-sphere fluid to restrictive one- and two-dimensional channels with smooth interacting walls modifies its structure, dynamics, and entropy using molecular dynamics and transition-matrix Monte Carlo simulations. Although confinement strongly affects local structuring, the relationships between self-diffusivity, excess entropy, and average fluid density are, to an excellent approximation, independent of channel width or particle-wall interactions. Thus, thermodynamics can be used to predict how confinement impacts dynamics.Comment: 4 pages, 4 figure

    Microscopy of Progressive Decay of Cottonwood by the Brown-Rot Fungus Gloeophyllum Trabeum

    Get PDF
    Eastern cottonwood (Populus deltoides Bartr.) samples subjected to various degrees of brown-rot decay by Gloeophyllum trabeum (FPL 617) were studied by scanning electron (SEM) and polarizing microscopy. A technique was developed to prepare decayed wood specimens for SEM. Ray cells were heavily decomposed in early stages of decay. Bore holes were produced in early stages to facilitate hyphal penetration into fiber tracheids. Degradation of fiber tracheid walls began with the formation of radial checks or voids in the S2 layer, followed by the removal of the entire S2 layer, which often caused the separation of the S3 layer from the remaining cell wall. The S3 layer often was removed before the decomposition of the S1 layer. The compound middle lamella remained intact even after the complete removal of the secondary wall

    Microscopy Of Progressive Decay Of Cottonwood By The Brown-Rot Fungus Gloeophyllum Trabeum

    Get PDF
    Eastern cottonwood (Populus deltoides Bartr.) samples subjected to various degrees of brown-rot decay by Gloeophyllum trabeum (FPL 617) were studied by scanning electron (SEM) and polarizing microscopy. A technique was developed to prepare decayed wood specimens for SEM. Ray cells were heavily decomposed in early stages of decay. Bore holes were produced in early stages to facilitate hyphal penetration into fiber tracheids. Degradation of fiber tracheid walls began with the formation of radial checks or voids in the S2 layer, followed by the removal of the entire S2 layer, which often caused the separation of the S3 layer from the remaining cell wall. The S3 layer often was removed before the decomposition of the S1 layer. The compound middle lamella remained intact even after the complete removal of the secondary wall

    Estructura, fábrica magnética y emplazamiento de los granitos de Brealito y La Paya, basamento del valle Calchaquí, Salta, Argentina

    Get PDF
    Los granitoides de Brealito y La Paya son plutones de formas elípticas alargadas en dirección N-S emplazados respectivamente en las Formaciones Puncoviscana y La Paya. El estudio de la estructura interna de los plutones se ha abordado aplicando la anisotropía de la susceptibilidad magnética (ASM). El plutón de La Paya presenta un carácter paramagnético (K entre 1,9 y 6,7 x10- 5 SI) con una fábrica magnética controlada por la biotita, en cambio el plutón de Brealito muestra un carácter mixto (K entre 22 y 466 x10- 5 SI) con algunas estaciones en las que la contribución ferromagnética (originada por magnetita) es dominante. Las anisotropías totales medidas son coherentes con el carácter magmático de las muestras analizadas. Ambos plutones presentan semejanzas desde el punto de vista estructural. Son cuerpos de forma lenticular, concordantes con el encajante y buzando hacia el Oeste. La lineación magnética presenta buzamientos suaves en dirección N-S.The Brealito and La Paya granitoids are elliptical-shaped plutons with N-S elongation. They intrude into the Puncoviscana and La Paya Formations, respectively. The internal structure of these plutons has been studied by using field structures and applying the Anisotropy of the Magnetic Susceptibility (AMS). The magnetic fabric of the La Paya pluton reflects the orientation of biotite, the main paramagnetic mineral in this granite (K between 1.9 and 6.7 x10-5SI). Instead, the magnetic behavior of the Brealito granite is more complex since not only paramagnetic minerals, but also the ferromagnetic contribution (K between 22 and 466 x10-5SI) of magnetite crystals strongly control the magnetic fabric of some samples. Total anisotropy values of the magnetic fabrics are coherent with the magmatic nature of the analized samples. From the structural point of view, both plutons display similarities. These granites are lozenge-shaped bodies concordant with the host rocks. Their planar fabrics are mainly NS-trending and West dipping, and magnetic lineations plunge at low angles along the N-S direction

    Monte Carlo Renormalization Group Analysis of Lattice Ï•4\phi^4 Model in D=3,4D=3,4

    Full text link
    We present a simple, sophisticated method to capture renormalization group flow in Monte Carlo simulation, which provides important information of critical phenomena. We applied the method to D=3,4D=3,4 lattice Ï•4\phi^4 model and obtained renormalization flow diagram which well reproduces theoretically predicted behavior of continuum Ï•4\phi^4 model. We also show that the method can be easily applied to much more complicated models, such as frustrated spin models.Comment: 13 pages, revtex, 7 figures. v1:Submitted to PRE. v2:considerably reduced redundancy of presentation. v3:final version to appear in Phys.Rev.

    Roman mining on Exmoor: a geomorphological approach at Anstey's Combe, Dulverton

    Get PDF
    A survey of valley fills in south-facing combes (headwater valleys) along the south side of the Exmoor massif revealed an anomalously deep infill in one valley. This infill of up to 5 m depth had been gullied revealing a complex stratigraphy. Studies of the stratigraphy, clast orientation and shape suggested several accumulation episodes under different environmental conditions commencing in a periglacial climatic regime. Later units included sandy silts which can be dated using optically stimulated luminescence (OSL) of quartz grains. The OSL dates, indicate that the inter-gravel silts accumulated in two periods, the Romano-British period and the 16th-17th centuries AD. A survey of the very small valley catchment revealed a linear trench of a type associated with early iron mining. Given the anomalously high volume of accumulated sediment from such a small catchment and evidence of mining on the slope above the site, the geomorphic mechanism is almost certainly the downslope transport of mining debris from the slope to the valley floor. This study suggests that the systematic survey of headwater valleys in metalliferous uplands may be one way of locating areas of early mining activity and that such deposits could provide a chronology of working and abandonment

    Properties of Interfaces in the two and three dimensional Ising Model

    Full text link
    To investigate order-order interfaces, we perform multimagnetical Monte Carlo simulations of the 2D2D and 3D3D Ising model. Following Binder we extract the interfacial free energy from the infinite volume limit of the magnetic probability density. Stringent tests of the numerical methods are performed by reproducing with high precision exact 2D2D results. In the physically more interesting 3D3D case we estimate the amplitude F0sF^s_0 of the critical interfacial tension Fs=F0stμF^s = F^s_0 t^\mu to be F0s=1.52±0.05F^s_0 = 1.52 \pm 0.05. This result is in good agreement with a previous MC calculation by Mon, as well as with experimental results for related amplitude ratios. In addition, we study in some details the shape of the magnetic probability density for temperatures below the Curie point.Comment: 25 pages; sorry no figures include

    Advanced biopolymer-coated drug-releasing titania nanotubes (TNTs) implants with simultaneously enhanced osteoblast adhesion and antibacterial properties

    Get PDF
    Abstract not availableTushar Kumeria, Htwe Mon, Moom Sinn Aw, Karan Gulati, Abel Santos, Hans J. Griesser, Dusan Losi
    • …
    corecore