A new model with Serpent for the first criticality benchmarks of the TRIGA Mark II reactor

We present a new model, developed with the Serpent Monte Carlo code, for neutronics simulation of the TRIGA Mark II reactor of Pavia (Italy). The complete 3D geometry of the reactor core is implemented with high accuracy and detail, exploiting all the available information about geometry and materials. The Serpent model of the reactor is validated in the fresh fuel configuration, through a benchmark analysis of the first criticality experiments and control rods calibrations. The accuracy of simulations in reproducing the reactivity difference between the low power (10 W) and full power (250 kW) reactor condition is also tested. Finally, a direct comparison between Serpent and MCNP simulations of the same reactor configurations is presented

SERPent: Automated reduction and RFI-mitigation software for e-MERLIN

The Scripted E-merlin Rfi-mitigation PipelinE for iNTerferometry (SERPent) is an automated reduction and RFI-mitigation procedure utilising the SumThreshold methodology (Offringa et al., 2010a), originally developed for the LOFAR pipeline. SERPent is written in the Parseltongue language enabling interaction with the Astronomical Image Processing Software (AIPS) program. Moreover, SERPent is a simple ‘out of the box’ Python script, which is easy to set up and is free of compilers. In addition to the flagging of RFI affected visibilities, the script also flags antenna zero-amplitude dropouts and Lovell telescope phase calibrator stationary scans inherent to the e-MERLIN system. Both the flagging and computational performances of SERPent are presented here, for e-MERLIN commissioning datasets for both L-band (1.3–1.8 GHz) and C-band (4–8 GHz) observations. RFI typically amounts to <20%–25% for the more problematic L-band observations and <5% for the generally RFI quieter C-band. The level of RFI detection and flagging is more accurate and delicate than visual manual flagging, with the output immediately ready for AIPS calibration. SERPent is fully parallelised and has been tested on a range of computing systems. The current flagging rate is at 110 GB day−1 on a ‘high-end’ computer (16 CPUs, 100 GB memory) which amounts to ∼6.9 GB CPU−1 day−1, with an expected increase in performance when e-MERLIN has completed its commissioning. The refining of automated reduction and calibration procedures is essential for the e-MERLIN legacy projects and future interferometers such as the SKA and the associated pathfinders (MeerKAT and ASKAP), where the vast data sizes (>TB) make traditional astronomer interactions unfeasible

Adam, Eve, and the Serpent

Reviewed Book: Pagels, Elaine H. Adam, Eve, and the Serpent. New York: Random House, 1990

Explanation of the sea-serpent magnetic structure of sunspot penumbrae

Recent spectro-polarimetric observations of a sunspot showed the formation of bipolar magnetic patches in the mid penumbra and their propagation toward the outer penumbral boundary. The observations were interpreted as being caused by sea-serpent magnetic fields near the solar surface (Sainz Dalda & Bellot Rubio 2008). In this Letter, we develop a 3D radiative MHD numerical model to explain the sea-serpent structure and the wave-like behavior of the penumbral magnetic field lines. The simulations reproduce the observed behavior, suggesting that the sea-serpent phenomenon is a consequence of magnetoconvection in a strongly inclined magnetic field. It involves several physical processes: filamentary structurization, high-speed overturning convective motions in strong, almost horizontal magnetic fields with partially frozen field lines, and traveling convective waves. The results demonstrate a correlation of the bipolar magnetic patches with high-speed Evershed downflows in the penumbra. This is the first time that a 3D numerical model of the penumbra results in downward directed magnetic fields, an essential ingredient of sunspot penumbrae that has eluded explanation until now.Comment: 9 pages, 3 figures, submitted to ApJ Letter

Women, Serpent and Devil: Female Devilry in Hindu and Biblical Myth and its Cultural Representation: A Comparative Study

Association of Women with Serpent and Devil or evil is common in today’s popular movies and literature. A large number of movies have been made on serpent woman, or Nagin-Kanya, both in India and the West in the last century. But the root of this popular trend lies in Genesis of the Bible, and its interpretations by the theologians and the church fathers. In India, this motif came with British literary and cultural products through colonization. Though we get references of figures (Ulupi in the Mahabharata, myth of snake-goddess Manasa) similar to the western serpent women in pre-colonial Indian literature and myth, they stand apart from the western serpent women for several reasons. Firstly, the serpent-women in pre-colonial literature are hardly demonized and denigrated like their western counterparts. Secondly, fatal temptation and destructive eroticism lie at the centre of the serpent woman myth in western literature and culture after Christianization. This article aims to trace the origin of serpent-woman myth and its cultural construction as well as representations in India and the West

Serpentine Imagery in Nineteenth-Century Prints

This thesis explores images of sea serpents in nineteenth-century print culture that reflect an ongoing effort throughout the century to locate, capture, catalogue, and eventually poeticize the sea serpent. My research centers primarily on the sea serpent craze that occurred within the New England and Mid-Atlantic states between 1845 and 1880 and examines the following three prints: Albert Koch’s Hydrarchos, a fossil skeleton hoax, printed in an 1845 advertisement by Benjamin Owen, a book and job printer; an 1868 Harper’s Weekly illustration titled The Wonderful Fish; and Stephen Alonzo Schoff’s etching, The Sea Serpent from 1880, based on an 1864 painting by Elihu Vedder. By examining the illustrations and eyewitness accounts of sea serpent sightings, it is possible to show how art infused historically specific meaning into the schematized and persistent form of the sea serpent. It is not only that people saw serpents that looked like the ones they had seen in pictures, but that the pictures offered a kind of template on which viewers could inscribe particular historical fears. I catalogue the evolution of serpent imagery during a time of political upheaval, including serious threats to national unity as well as threats to the racial, gender, and social hierarchy that had underpinned the republic’s early order. The sea serpent motif could be adapted to different threats to social stability. I argue that the search to locate a physical or “actual” sea serpent body, founded in such anxieties, shaped the design and meaning of serpent images, all the more so because artists and viewers began with certain schemas, which are reflected in the illustrations that often accompanied sea serpent sightings. Taking into account the booming mass media of the era, changing practices in natural history and science, a burgeoning culture of hoax and publicity stunts, attitudes about war and violence, and concepts of human beauty and sexuality, this thesis explores how the monstrous body of the sea serpent thrived in the nineteenth-century United States. Adviser: Wendy Kat

Stokes posets and serpent nests

We study two different objects attached to an arbitrary quadrangulation of a regular polygon. The first one is a poset, closely related to the Stokes polytopes introduced by Baryshnikov. The second one is a set of some paths configurations inside the quadrangulation, satisfying some specific constraints. These objects provide a generalisation of the existing combinatorics of cluster algebras and nonnesting partitions of type A.Comment: 24 pages, 12 figure

Recovery at Morvin: SERPENT final report

Recovery from disturbance is poorly understood in deep water, but the extent of anthropogenic impacts is becoming increasingly well documented. We used Remotely Operated Vehicles (ROV) to visually assess the change in benthic habitat after exploratory hydrocarbon drilling disturbance around the Morvin well located at 380m depth in the Norwegian Sea.An ROV, launched directly from the rig drilling the well in 2006 was used to carry out video transects around the well before drilling and immediately after. On a return to the site three years after disturbance a larger survey was conducted with a ship-launched ROV in 2009. Transects were repeated at the disturbed area and random background transects were taken. Visible drill cuttings were mapped for each survey, and positions and counts of epibenthic invertebrate megafauna were determined, revealing a fauna dominated by Cnidaria (45% of total observations) and Porifera (33%).Immediately after disturbance a visible cuttings pile extended to over 100m from the well and megafaunal density was significantly reduced (0.07 individuals m-2) in comparison to pre-drill data (0.23 ind. m-2). Three years later the visible extent of the cuttings pile had reduced in size, reaching 60m from the well and considerably less in some headings. In comparison to background transects (0.21 ind. m-2), megafaunal density was significantly reduced on the remaining cuttings (0.04m-2), but beyond the visible disturbance there was no significant difference (0.15m-2). The investigation at this site shows a return to background densities of megafaunal organisms over a large extent of the area previously disturbed. However a central area, where the initial cuttings pile was deepest, demonstrated reduced sessile megafaunal density which persisted three years after disturbance. Elevated Barium concentration and reduced sediment grain size suggests persistence of disturbance beyond the remaining visibly impacted area which may result in changes to the infaunal communities undetectable by ROV video survey

Analysis of the cell-specific expression of the serpent gene and its role as a cell -fate switch in Drosophila melanogaster

A universal problem in the development of complex organisms is programming totipotent cells into specialized cell types. I have focused on the Drosophila fat body and the characterization of the positional information required for the adoption of a fat cell identity by mesodermal cells. Central to this study is serpent, a transcription factor gene, both necessary and sufficient for fat-cell development; I characterized the patterns of activity for regulatory regions that control serpent expression within the fat body. The fat body is composed of three morphological domains (lateral fat body, ventral commissure, and dorsal fat cell projections) each of which requires serpent activity. Using these enhancer-regions in reporter-gene constructs, I traced the development of the dorsal fat-cell projections, the ventralmost lateral fat body, and a portion of the ventral commissure, and demonstrated that particular groups of fat-cell clusters give rise to these domains; In parallel, I determined, through mutant and misexpression genetic analysis, that the transcription factor genes, Abdominal B and tinman, are critical for serpent activation within the dorsal fat-cell cluster. Putative binding sites for these factors are present within the regulatory regions of serpent. Differing cues activate serpent in distinct embryonic regions, and I discuss the possibility that these factors are also important for the establishment of genetic differences among fat cells, and thus, functional differentiation of the fat body. Additionally, I genetically tested Ultrabithorax , another transcription factor gene with putative binding sites within one serpent-enhancer region, for its ability to regulate serpent expression. I determined that Ultabithorax is not involved in fat-cell specification, but is required for the proper morphological development of the fat body; I have also tested the proposal that within the lateral mesoderm, serpent is a cell-type switch between fat and somatic gonadal precursor cells. I find that serpent does not serve as a switch between these two cell choices. However, I provide evidence for a similar cell-fate switch, in the dorsal mesoderm, between dorsal fat cells and circular visceral muscle precursors. This switch relies on both serpent and the homeotic transcription factor, Abdominal B