Experimental Validation of Multiphase Flow Models and Testing of Multiphase Flow Meters: A Critical Review of Flow Loops Worldwide

Around the world, research into multiphase flow is performed by scientists with hugely diverse backgrounds: physicists, mathematicians and engineers from mechanical, nuclear, chemical, civil, petroleum, environmental and aerospace disciplines. Multiphase flow models are required to investigate the co-current or counter-current flow of different fluid phases under a wide range of pressure and temperature conditions and in several different configurations. To compliment this theoretical effort, measurements at controlled experimental conditions are required to verify multiphase flow models and assess their range of applicability, which has given rise to a large number of multiphase flow loops around the world. These flow loops are also used intensively to test and validate multiphase flow meters, which are devices for the in-line measurement of multiphase flow streams without separation of the phases. However, there are numerous multiphase flow varieties due to differences in pressure and temperature, fluids, flow regimes, pipe geometry, inclination and diameter, so a flow loop cannot represent all possible situations. Even when experiments in a given flow loop are believed to be sufficiently exhaustive for a specific study area, the real conditions encountered in the field tend to be very different from those recreated in the research facility. This paper presents a critical review of multiphase flow loops around the world, highlighting the pros and cons of each facility with regard to reproducing and monitoring different multiphase flow situations. The authors suggest a way forward for new developments in this area

Experimental validation of multiphase flow models and testing of multiphase flow meters: A critical review of flow loops worldwide

Around the world, research into multiphase flow is performed by scientists with hugely diverse backgrounds: physicists, mathematicians and engineers from mechanical, nuclear, chemical, civil, petroleum, environmental and aerospace disciplines. Multiphase flow models are required to investigate the co-current or counter-current flow of different fluid phases under a wide range of pressure and temperature conditions and in several different configurations. To compliment this theoretical effort, measurements at controlled experimental conditions are required to verify multiphase flow models and assess their range of applicability, which has given rise to a large number of multiphase flow loops around the world. These flow loops are also used intensively to test and validate multiphase flow meters, which are devices for the in-line measurement of multiphase flow streams without separation of the phases. However, there are numerous multiphase flow varieties due to differences in pressure and temperature, fluids, flow regimes, pipe geometry, inclination and diameter, so a flow loop cannot represent all possible situations. Even when experiments in a given flow loop are believed to be sufficiently exhaustive for a specific study area, the real conditions encountered in the field tend to be very different from those recreated in the research facility. This paper presents a critical review of multiphase flow loops around the world, highlighting the pros and cons of each facility with regard to reproducing and monitoring different multiphase flow situations. The authors suggest a way forward for new developments in this area

The labial gene is required to terminate proliferation of identified neuroblasts in postembryonic development of the Drosophila brain

The developing brain of Drosophila has become a useful model for studying the molecular genetic mechanisms that give rise to the complex neuronal arrays that characterize higher brains in other animals including mammals. Brain development in Drosophila begins during embryogenesis and continues during a subsequent postembryonic phase. During embryogenesis, the Hox gene labial is expressed in the developing tritocerebrum, and labial loss-of-function has been shown to be associated with a loss of regional neuronal identity and severe patterning defects in this part of the brain. However nothing is known about the expression and function of labial, or any other Hox gene, during the postembryonic phase of brain development, when the majority of the neurons in the adult brain are generated. Here we report the first analysis of Hox gene action during postembryonic brain development in Drosophila. We show that labial is initially expressed in six larval brain neuroblasts, of which only four give rise to the labial expressing neuroblast lineages present in the late larval brain. Although MARCM-based clonal mutation of labial in these four neuroblast lineages does not result in an obvious phenotype, a striking and unexpected effect of clonal labial loss-of-function does occur during postembryonic brain development, namely the formation of two ectopic neuroblast lineages that are not present in wild-type brains. The same two ectopic neuroblast lineages are also observed following cell death blockage and, significantly, in this case the resulting ectopic lineages are Labial-positive. These findings imply that labial is required in two specific neuroblast lineages of the wildtype brain for the appropriate termination of proliferation through programmed cell death. Our analysis of labial function reveals a novel cell autonomous role of this Hox gene in shaping the lineage architecture of the brain during postembryonic development

High-resolution imaging spectroscopy of two micro-pores and an arch filament system in a small emerging-flux region

Aims. The purpose of this investigation is to characterize the temporal evolution of an emerging flux region, the associated photospheric and chromospheric flow fields, and the properties of the accompanying arch filament system. Methods. This study is based on imaging spectroscopy with the G\"ottingen Fabry-P\'erot Interferometer at the Vacuum Tower Telescope, on 2008 August 7. Cloud model (CM) inversions of line scans in the strong chromospheric absorption H$\alpha$ line yielded CM parameters, which describe the cool plasma contained in the arch filament system. Results. The observations cover the decay and convergence of two micro-pores with diameters of less than one arcsecond and provide decay rates for intensity and area. The photospheric horizontal flow speed is suppressed near the two micro-pores indicating that the magnetic field is sufficiently strong to affect the convective energy transport. The micro-pores are accompanied by an arch filament system, where small-scale loops connect two regions with H$\alpha$ line-core brightenings containing an emerging flux region with opposite polarities. The chromospheric velocity of the cloud material is predominantly directed downwards near the footpoints of the loops with velocities of up to 12 km/s, whereas loop tops show upward motions of about 3 km/s. Conclusions. Micro-pores are the smallest magnetic field concentrations leaving a photometric signature in the photosphere. In the observed case, they are accompanied by a miniature arch filament system indicative of newly emerging flux in the form of $\Omega$-loops. Flux emergence and decay take place on a time-scale of about two days, whereas the photometric decay of the micro-pores is much more rapid (a few hours), which is consistent with the incipient submergence of $\Omega$-loops. The results are representative for the smallest emerging flux regions still recognizable as such.Comment: 15 pages, 16 figures, 3 tables, published in A&

Lithologic Character of the Paleozoic Sandstone Succession, Southern Ozark Region, Arkansas, and Missouri

Sandstones comprise nearly half of the Paleozoic (Upper Cambrian-Middle Pennsylvania) lithostratigraphic succession in the southern Ozark region of northern Arkansas and southern Missouri. They record five distinct, but related intervals characterized by 1) Upper Cambrian arkoses resting unconformably on Precambrian granite; 2) Lower Ordovician reworked subarkoses, sublitharentites, and quartzites; 3) Lower Ordovician to Lower Mississippian reworked orthoquartzites; 4) Upper Mississippian first cycle sandstones with few metamorphic rock fragments (mrfs); 5) Lower Pennsylvanian (Morrowan) first cycle sandstones with common mrfs and Middle Pennsylvanian (Atokan) first cycle sandstones with common to abundant mrfs. These sandstones accumulated on a gently sloping cratonic platform reflecting transgressive-regressive, epeiric seas that eroded, transported, reworked and deposited more than 914.4m (3000ft) of terrigenous clastic sediments across what is now the south flank of the Ozark Dome

Sequence Stratigraphic and Tectono-Stratigraphic Successions, Ozark Shelf, Tri-State Region, Southern Midcontinent

The southern Ozark region, Arkansas, Missouri, and Oklahoma occupies the southern border of the North American craton. Its sedimentary succession preserves a complete Wilson Cycle reflecting the Late Precambrian-Cambrian rifting of Rodinia into the Laurussian and Gondwanan landmasses that opened the Iapetus Ocean Basin during the Late Cambrian-Middle Mississippian. The basin was closed during the Late Mississippian-Middle Pennsylvanian by the collision of Laurussia with Gondwana. During the Late Cambrian through the Middle Pennsylvanian, the Ozark Shelf, including its gently sloping, Northern Arkansas Structural Platform (NASP) and adjacent ramp, records both transgression and regression by epeiric seas as well as regional tectonism that can be recognized as five Tectono-Stratigraphic Successions (TS) and correlated readily with the Sloss Cratonic Sequences. The TS record comprises at least 33 named formations with a potential thickness \u3e2926m (9600ft). However, both eustatic and tectonic sea-level rise and fall also produced regional surfaces of erosion that punctuated deposition, and the preserved thickness on the NASP is significantly less. The five distinct, but related, Tectono-stratigraphic Successions in the Paleozoic record are (TS1) Late Precambrian-Middle Cambrian, (TS2) Upper Cambrian-lowest Ordovician, (TS3) Lower Ordovician-Lower Devonian, (TS4) Middle Devonian-Upper Mississippian, and (TS5) Lower-Middle Pennsylvanian. TS1, a pre-Late Sauk Sequence, is the least well-known succession, consisting of emplaced igneous and low-ranked metasedimentary bodies and pre-Lamotte sedimentary rocks. TS2, Late Sauk Sequence, is potentially \u3e937m (3075ft) of dolomites and sandstones. TS3, Tippecanoe Sequence, is the penultimate thickest interval, possibly \u3e1257m (4125ft) of dolomites, limestones, shales, and supermature sandstones. TS4, Kaskaskia Sequence, measures at least 736m (2416ft). The final TS5, Lower Absaroka Sequence of first cycle sandstones with variable amounts of mrfs, and shales is the thickest interval, \u3e1267m (4160ft) and may exceed 7620m (25,000ft) in the adjacent Arkoma Basin

The meaning of different forms of structural myocardial injury, immune response and timing of infarct necrosis and cardiac repair

Although a decline in the all-cause and cardiac mortality rates following myocardial infarction (MI) during the past 3 decades has been reported, MI is a major cause of death and disability worldwide. From a pathological point of view MI consists in a particular myocardial cell death due to prolonged ischemia. After the onset of myocardial ischemia, cell death is not immediate, but takes a finite period of time to develop. Once complete myocytes’ necrosis has occurred, a process leading to a healed infarction takes place. In fact, MI is a dynamic process that begins with the transition from reversible to irreversible ischemic injury and culminates in the replacement of dead myocardium by a fibrous scar. The pathobiological mechanisms underlying this process are very complex, involving an inflammatory response by several pathways, and pose a major challenge to ability to improve our knowledge. An improved understanding of the pathobiology of cardiac repair after MI and further studies of its underlying mechanisms provide avenues for the development of future strategies directed toward the identification of novel therapies. The chronologic dating of MI is of great importance both to clinical and forensic investigation, that is, the ability to create a theoretical timeline upon which either clinicians or forensic pathologists may increase their ability to estimate the time of MI. Aging of MI has very important practical implications in clinical practice since, based on the chronological dating of MI, attractive alternatives to solve therapeutic strategies in the various phases of MI are developing

Observations of solar small-scale magnetic flux-sheet emergence

Aims. Moreno-Insertis et al. (2018) recently discovered two types of flux emergence in their numerical simulations: magnetic loops and magnetic sheet emergence. Whereas magnetic loop emergence has been documented well in the last years, by utilising high-resolution full Stokes data from ground-based telescopes as well as satellites, magnetic sheet emergence is still an understudied process. We report here on the first clear observational evidence of a magnetic sheet emergence and characterise its development. Methods. Full Stokes spectra from the Hinode spectropolarimeter were inverted with the SIR code to obtain solar atmospheric parameters such as temperature, line-of-sight velocities and full magnetic field vector information. Results. We analyse a magnetic flux emergence event observed in the quiet-sun internetwork. After a large scale appearance of linear polarisation, a magnetic sheet with horizontal magnetic flux density of up to 194 Mx/cm$^{2}$ hovers in the low photosphere spanning a region of 2 to 3 arcsec. The magnetic field azimuth obtained through Stokes inversions clearly shows an organised structure of transversal magnetic flux density emerging. The granule below the magnetic flux-sheet tears the structure apart leaving the emerged flux to form several magnetic loops at the edges of the granule. Conclusions. A large amount of flux with strong horizontal magnetic fields surfaces through the interplay of buried magnetic flux and convective motions. The magnetic flux emerges within 10 minutes and we find a longitudinal magnetic flux at the foot points of the order of $\sim$$10^{18}$ Mx. This is one to two orders of magnitude larger than what has been reported for small-scale magnetic loops. The convective flows feed the newly emerged flux into the pre-existing magnetic population on a granular scale.Comment: 6 pages, 5 figures, accepted as a letter in A&

Computer-aided Melody Note Transcription Using the Tony Software: Accuracy and Efficiency

accepteddate-added: 2015-05-24 19:18:46 +0000 date-modified: 2017-12-28 10:36:36 +0000 keywords: Tony, melody, note, transcription, open source software bdsk-url-1: https://code.soundsoftware.ac.uk/attachments/download/1423/tony-paper_preprint.pdfdate-added: 2015-05-24 19:18:46 +0000 date-modified: 2017-12-28 10:36:36 +0000 keywords: Tony, melody, note, transcription, open source software bdsk-url-1: https://code.soundsoftware.ac.uk/attachments/download/1423/tony-paper_preprint.pdfWe present Tony, a software tool for the interactive an- notation of melodies from monophonic audio recordings, and evaluate its usability and the accuracy of its note extraction method. The scientific study of acoustic performances of melodies, whether sung or played, requires the accurate transcription of notes and pitches. To achieve the desired transcription accuracy for a particular application, researchers manually correct results obtained by automatic methods. Tony is an interactive tool directly aimed at making this correction task efficient. It provides (a) state-of-the art algorithms for pitch and note estimation, (b) visual and auditory feedback for easy error-spotting, (c) an intelligent graphical user interface through which the user can rapidly correct estimation errors, (d) extensive export functions enabling further processing in other applications. We show that Tony’s built in automatic note transcription method compares favourably with existing tools. We report how long it takes to annotate recordings on a set of 96 solo vocal recordings and study the effect of piece, the number of edits made and the annotator’s increasing mastery of the software. Tony is Open Source software, with source code and compiled binaries for Windows, Mac OS X and Linux available from https://code.soundsoftware.ac.uk/projects/tony/

Efecto de la regulación de la cabecera del río Genil (Sierra Nevada, España) sobre la comunidad de macroinvertebrados acuáticos y la dieta larvaria de Rhyacophila nevada (Insecta : Trichoptera)

Se analiza el efecto que un embalse (Embalse de Canales), situado en la parte alta de un río de montaña (Río Genil, Sierra Nevada, Granada, España), tiene sobre la comunidad de macroinvertebrados, y en especial sobre la dieta de las larvas del tricóptero depredador Rhyacophila nevada Zamora-Muñoz, C. & Alba-Tercedor, 1992. Para ello se establecieron estaciones de muestreo aguas arriba y abajo del embalse, realizándose muestreos cuantitativos de macroinvertebrados con una periodicidad mensual. Los macroinvertebrados (MIB) se identificaron hasta el máximo nivel taxonómico posible (en la mayoría de los casos a nivel de especie). La mayor diversidad específica se encontró en los dípteros quironómidos. Se estimó también la biomasa por especie (PSLC) y los ciclos de vida de las especies de depredadores, efemerópteros y dípteros. El contenido de los tractos digestivos fue analizado y cuantificado. La diversidad de los MIB estuvo determinada por los cambios de flujo y los ciclos de vida de las presas. Rhyacophila nevada es el depredador más abundante, presenta un ciclo multivoltino, comportándose como un depredador que busca activamente sus presas que ingiere comenzando por la región caudal. El número de presas en R. nevada aumentó con su tamaño. Las diferencias significativas de la dieta entre las estaciones de muestreo son consecuencia de los cambios en la disponibilidad de recursos (presas) en el tiempo. El ancho de nicho trófico también mostró diferencias entre estaciones.The effect that a dam (the Canales dam), located in the upper part of a mountain river (Genil stream, Sierra Nevada, Spain), has on the macroinvertebrate community, is analysed, especially over the larval diet of the predator caddisfly Rhyacophila nevada Zamora-Muñoz, C. & Alba-Tercedor, 1992. To that end, sampling stations were established, upstream and downstream of the dam. Quantitative samplings of macroinvertebrates were realized every month. The macroinvertebrates were identified to the maximum taxonomical level (species level in the majority of cases). The highest specific diversity was found in the chironomidae Diptera. The biomass per species was estimated , as well as the life cycles of the predator's species, mayflies and dipterans. Gut contents were analysed and quantified. The diversity of the MIB was determined by flow shifts and prey life cycles. Rhyacophila nevada is the most abundant predator, with a multivoltine life cycle, and behaving as an active searcher of preys, ingesting them from the caudal region. The number of prey items consumed by R. nevada increased with its size. Significant differences on the diet between the sampling stations are a consequence of the shift in the resource availability of preys in time. The trophic niche breadth was different among sites