On the effects of internal heat sources upon forced convection in porous channels with asymmetric thick walls

Thermal behaviour of a porous channel with thick, solid walls featuring uneven wall thicknesses and asymmetric external thermal boundary conditions is analysed theoretically. The system is under forced convection and the fluid and solid phases in this configuration include internal heat sources with varying strengths. Two types of asymmetric boundary conditions are considered. These include constant but different prescribed temperatures on the upper and lower solid walls and a combination of constant heat flux and convective boundary conditions on the two sides of the channel. The Darcy-Brinkman model of momentum transport and the two-equation energy model are utilised to develop analytical solutions for the temperature fields and Nusselt number. A comprehensive parametric study is, subsequently, conducted. The results clearly show the pronounced effect of the internal heat sources upon the Nusselt number and temperature fields of the system. In particular, the existence of these source terms intensifies the occurrence of a bifurcation phenomenon in the temperature fields. In keeping with the recent literature, it is demonstrated that the inclusion of internal heat sources leads to deviations from the local thermal equilibrium. Nonetheless, the results imply that the extent of these deviations depends on the thermal boundary conditions and also the specific phase in which heat is generated or consumed

Pandora Operation and Analysis Software

Pandora Operation and Analysis Software controls the Pandora Sun- and sky-pointing optical head and built-in filter wheels (neutral density, UV bandpass, polarization filters, and opaque). The software also controls the attached spectrometer exposure time and thermoelectric cooler to maintain the spectrometer temperature to within 1 C. All functions are available through a GUI so as to be easily accessible by the user. The data are automatically stored on a miniature computer (netbook) for automatic download to a designated server at user defined intervals (once per day, once per week, etc.), or to a USB external device. An additional software component reduces the raw data (spectrometer counts) to preliminary scientific products for quick-view purposes. The Pandora systems are built from off-the-shelf commercial parts and from mechanical parts machined using electronic machine shop drawings. The Pandora spectrometer system is designed to look at the Sun (tracking to within 0.1 ), or to look at the sky at any zenith or azimuth angle, to gather information about the amount of trace gases or aerosols that are present

Erratum to “On the effects of internal heat sources upon forced convection in porous channels with asymmetric thick walls” [Int. Comm. Heat Mass Trans. 73 (2016) 100–110]

No abstract available

High Precision, Absolute Total Column Ozone Measurements from the Pandora Spectrometer System: Comparisons with Data from a Brewer Double Monochromator and Aura OMI

We present new, high precision, high temporal resolution measurements of total column ozone (TCO) amounts derived from ground-based direct-sun irradiance measurements using our recently deployed Pandora single-grating spectrometers. Pandora's small size and portability allow deployment at multiple sites within an urban air-shed and development of a ground-based monitoring network for studying small-scale atmospheric dynamics, spatial heterogeneities in trace gas distribution, local pollution conditions, photochemical processes and interdependencies of ozone and its major precursors. Results are shown for four mid- to high-latitude sites where different Pandora instruments were used. Comparisons with a well calibrated double-grating Brewer spectrometer over a period of more than a year in Greenbelt MD showed excellent agreement and a small bias of approximately 2 DU (or, 0.6%). This was constant with slant column ozone amount over the full range of observed solar zenith angles (15-80), indicating adequate Pandora stray light correction. A small (1-2%) seasonal difference was found, consistent with sensitivity studies showing that the Pandora spectral fitting TCO retrieval has a temperature dependence of 1% per 3K, with an underestimation in temperature (e.g., during summer) resulting in an underestimation of TCO. Pandora agreed well with Aura-OMI (Ozone Measuring Instrument) satellite data, with average residuals of <1% at the different sites when the OMI view was within 50 km from the Pandora location and OMI-measured cloud fraction was <0.2. The frequent and continuous measurements by Pandora revealed significant short-term (hourly) temporal changes in TCO, not possible to capture by sun-synchronous satellites, such as OMI, alone

Clinical and radiographic outcomes of an all-polyethylene fluted central peg glenoid component, implanted utilizing an off-label, uncemented technique, at a minimum 5-year follow-up

A

Mapping and Scheduling in Heterogeneous NoC through Population-Based Incremental Learning

ABSTRACT: Network-on-Chip (NoC) is a growing and promising communication paradigm for Multiprocessor-System-On-Chip (MPSoC) design, because of its scalability and performance features. In designing such systems, mapping and scheduling are becoming critical stages, because of the increase of both size of the network and application’s complexity. Some reported solutions solve each issue independently. However, a conjoint approach for solving mapping and scheduling allows to take into account both computation and communication objectives simultaneously. This paper shows a mapping and scheduling solution, which is based on a Population-Based Incremental Learning (PBIL) algorithm. The simulation results suggest that our PBIL approach is able to find optimal mapping and scheduling, in a multi-objective fashion. A 2-D heterogeneous mesh was used as target architecture for implementation, although the PBIL representation is suited to deal with more complex architectures, such as 3-D meshes

Semi-Automated Library Preparation for High-Throughput DNA Sequencing Platforms

Next-generation sequencing platforms are powerful technologies, providing gigabases of genetic information in a single run. An important prerequisite for high-throughput DNA sequencing is the development of robust and cost-effective preprocessing protocols for DNA sample library construction. Here we report the development of a semi-automated sample preparation protocol to produce adaptor-ligated fragment libraries. Using a liquid-handling robot in conjunction with Carboxy Terminated Magnetic Beads, we labeled each library sample using a unique 6 bp DNA barcode, which allowed multiplex sample processing and sequencing of 32 libraries in a single run using Applied Biosystems' SOLiD sequencer. We applied our semi-automated pipeline to targeted medical resequencing of nuclear candidate genes in individuals affected by mitochondrial disorders. This novel method is capable of preparing as much as 32 DNA libraries in 2.01 days (8-hour workday) for emulsion PCR/high throughput DNA sequencing, increasing sample preparation production by 8-fold

Virtual classroom proficiency-based progression for robotic surgery training (VROBOT): a randomised, prospective, cross-over, effectiveness study

Robotic surgery training has lacked evidence-based standardisation. We aimed to determine the effectiveness of adjunctive interactive virtual classroom training (VCT) in concordance with the self-directed Fundamentals of Robotic Surgery (FRS) curriculum. The virtual classroom is comprised of a studio with multiple audio-visual inputs to which participants can connect remotely via the BARCO weConnect platform. Eleven novice surgical trainees were randomly allocated to two training groups (A and B). In week 1, both groups completed a robotic skills induction. In week 2, Group A received training with the FRS curriculum and adjunctive VCT; Group B only received access to the FRS curriculum. In week 3, the groups received the alternate intervention. The primary outcome was measured using the validated robotic-objective structured assessment of technical skills (R-OSAT) at the end of week 2 (time-point 1) and 3 (time-point 2). All participants completed the training curriculum and were included in the final analyses. At time-point 1, Group A achieved a statistically significant greater mean proficiency score compared to Group B (44.80 vs 35.33 points, p = 0.006). At time-point 2, there was no significant difference in mean proficiency score in Group A from time-point 1. In contrast, Group B, who received further adjunctive VCT showed significant improvement in mean proficiency by 9.67 points from time-point 1 (95% CI 5.18-14.15, p = 0.003). VCT is an effective, accessible training adjunct to self-directed robotic skills training. With the steep learning curve in robotic surgery training, VCT offers interactive, expert-led learning and can increase training effectiveness and accessibility

Evolutionary genomics of anthroponosis in Cryptosporidium

Human cryptosporidiosis is the leading protozoan cause of diarrhoeal mortality worldwide, and a preponderance of infections is caused by Cryptosporidium hominis and C. parvum. Both species consist of several subtypes with distinct geographical distributions and host preferences (that is, generalist zoonotic and specialist anthroponotic subtypes). The evolutionary processes that drive the adaptation to the human host and the population structures of Cryptosporidium remain unknown. In this study, we analyse 21 whole-genome sequences to elucidate the evolution of anthroponosis. We show that Cryptosporidium parvum splits into two subclades and that the specialist anthroponotic subtype IIc-a shares a subset of loci with C. hominis that is undergoing rapid convergent evolution driven by positive selection. C. parvum subtype IIc-a also has an elevated level of insertion and deletion mutations in the peri-telomeric genes, which is also a characteristic of other specialist subtypes. Genetic exchange between Cryptosporidium subtypes plays a prominent role throughout the evolution of the genus. Interestingly, recombinant regions are enriched for positively selected genes and potential virulence factors, which indicates adaptive introgression. Analysis of 467 gp60 sequences collected from locations across the world shows that the population genetic structure differs markedly between the main zoonotic subtype (isolation-by-distance) and the anthroponotic subtype (admixed population structure). We also show that introgression between the four anthroponotic Cryptosporidium subtypes and species included in this study has occurred recently, probably within the past millennium