Measuring Condensation Heat Transfer on Superhydrophobic Surfaces

Condensation heat transfer is significant in many applications such as desalination, energy conversion, atmospheric water harvesting, electronics cooling, and other high heat flux applications. However, condensate on the surface adds a thermal resistance that limits condensation rates. The rate of condensation heat transfer is inversely proportional to the diameter of the condensate drops. In industrial condensing systems, the resistance is minimized by removing the condensate via gravity or a vapor shear, but the minimum size of droplet removal is typically on the order of the capillary length of the condensate, about 2.7 mm for water

An Optical-based Aggregate Approach to Measuring Condensation Heat Transfer

Condensation heat transfer is significant in many applications such as such as desalination, energy conversion [1], atmospheric water harvesting [2, 3], electronics cooling, and other high heat flux applications [4]. However, condensate on the surface adds a thermal resistance that limits condensation rates. The rate of condensation heat transfer is inversely proportional to the diameter of the condensate drops [5]. In industrial condensing systems, the resistance is minimized by removing the condensate via gravity or a vapor shear, but the minimum size of droplet removal is typically on the order of the capillary length of the condensate, about 2.7 mm for water

Rare manifestation of a c.290 C\u3eT, p.Gly97Glu VCP mutation

Introduction. The valosin-containing protein (VCP) regulates several distinct cellular processes. Consistent with this, VCP mutations manifest variable clinical phenotypes among and within families and are a diagnostic challenge. Methods. A 60-year-old man who played ice hockey into his 50’s was evaluated by electrodiagnostics, muscle biopsy, and molecular genetics. Results. With long-standing pes cavus and toe walking, our patient developed progressive weakness, cramps, memory loss, and paresthesias at age 52. An axonal sensorimotor neuropathy was found upon repeated testing at age 58. Neuropathic histopathology was present in the quadriceps, and exome sequencing revealed the VCP mutation c.290 C>T, p.Gly97Glu. Conclusions. Our patient reflects the clinical heterogeneity of VCP mutations, as his neurological localization is a spectrum between a lower motor neuron disorder and a hereditary axonal peripheral neuropathy such as CMT2. Our case demonstrates a rare manifestation of the c.290 C>T, pGly97Glu VCP mutation

A Direct Measurement of the Total Gas Column Density in Orion KL

The large number of high-J lines of C^(18)O available via the Herschel Space Observatory provide an unprecedented ability to model the total CO column density in hot cores. Using the emission from all the observed lines (up to J = 15-14), we sum the column densities in each individual level to obtain the total column after correcting for the population in the unobserved states. With additional knowledge of source size, V_(LSR), and line width, and both local thermodynamic equilibrium (LTE) and non-LTE modeling, we have determined the total C^(18)O column densities in the Extended Ridge, Outflow/Plateau, Compact Ridge, and Hot Core components of Orion KL to be 1.4 × 10^(16) cm^(–2), 3.5 × 10^(16) cm^(–2), 2.2 × 10^(16) cm^(–2), and 6.2 × 10^(16) cm^(–2), respectively. We also find that the C^(18)O/C^(17)O abundance ratio varies from 1.7 in the Outflow/Plateau, 2.3 in the Extended Ridge, 3.0 in the Hot Core, and to 4.1 in the Compact Ridge. This is in agreement with models in which regions with higher ultraviolet radiation fields selectively dissociate C^(17)O, although care must be taken when interpreting these numbers due to the size of the uncertainties in the C^(18)O/C^(17)O abundance ratio

An adaptation algorithm for an intelligent natural language tutoring system

The focus of computerised learning has shifted from content delivery towards personalised online learning with Intelligent Tutoring Systems (ITS). Oscar Conversational ITS (CITS) is a sophisticated ITS that uses a natural language interface to enable learners to construct their own knowledge through discussion. Oscar CITS aims to mimic a human tutor by dynamically detecting and adapting to an individual's learning styles whilst directing the conversational tutorial. Oscar CITS is currently live and being successfully used to support learning by university students. The major contribution of this paper is the development of the novel Oscar CITS adaptation algorithm and its application to the Felder–Silverman learning styles model. The generic Oscar CITS adaptation algorithm uniquely combines the strength of an individual's learning style preference with the available adaptive tutoring material for each tutorial question to decide the best fitting adaptation. A case study is described, where Oscar CITS is implemented to deliver an adaptive SQL tutorial. Two experiments are reported which empirically test the Oscar CITS adaptation algorithm with students in a real teaching/learning environment. The results show that learners experiencing a conversational tutorial personalised to their learning styles performed significantly better during the tutorial than those with an unmatched tutorial

The type IIb SN 2008ax: the nature of the progenitor

A source coincident with the position of the type IIb supernova (SN) 2008ax is identified in pre-explosion Hubble Space Telescope (HST) Wide Field Planetary Camera 2 observations in three optical filters. We identify and constrain two possible progenitor systems: (i) a single massive star that lost most of its hydrogen envelope through radiatively driven mass loss processes, prior to exploding as a helium-rich Wolf-Rayet star with a residual hydrogen envelope, and (ii) an interacting binary in a low mass cluster producing a stripped progenitor. Late time, high resolution observations along with detailed modelling of the SN will be required to reveal the true nature of this progenitor star.Comment: 5 pages, 2 figures, resolution of figure 1 reduced, figure 2 revised, some revision following referee's comments, accepted for publication in MNRAS letter

The European Large Area ISO Survey II: mid-infrared extragalactic source counts

We present preliminary source counts at 6.7um and 15um from the Preliminary Analysis of the European Large Area ISO survey, with limiting flux densities of \~2mJy at 15um & ~1mJy at 6.7um. We separate the stellar contribution from the extragalactic using identifications with APM sources made with the likelihood ratio technique. We quantify the completeness & reliability of our source extraction using (a) repeated observations over small areas, (b) cross-IDs with stars of known spectral type, (c) detections of the PSF wings around bright sources, (d) comparison with independent algorithms. Flux calibration at 15um was performed using stellar IDs; the calibration does not agree with the pre-flight estimates, probably due to effects of detector hysteresis and photometric aperture correction. The 6.7um extragalactic counts are broadly reproduced in the Pearson & Rowan-Robinson model, but the Franceschini et al. (1997) model underpredicts the observed source density by ~0.5-1 dex, though the photometry at 6.7um is still preliminary. At 15um the extragalactic counts are in excellent agreement with the predictions of the Pearson & Rowan-Robinson (1996), Franceschini et al. (1994), Guiderdoni et al. (1997) and the evolving models of Xu et al. (1998), over 7 orders of magnitude in 15um flux density. The counts agree with other estimates from the ISOCAM instrument at overlapping flux densities (Elbaz et al. 1999), provided a consistent flux calibration is used. Luminosity evolution at a rate of (1+z)^3, incorporating mid-IR spectral features, provides a better fit to the 15um differential counts than (1+z)^4 density evolution. No-evolution models are excluded, and implying that below around 10mJy at 15um the source counts become dominated by an evolving cosmological population of dust-shrouded starbursts and/or active galaxies.Comment: MNRAS in press. 14 pages, uses BoxedEPS (included). For more information on the ELAIS project see http://athena.ph.ic.ac.uk