The Separation Angle for Spheres in a Pipeline

The results of a series of experiments on the measurement of the angle of separation for flow over steel spheres suspended in a vertical 5.18 cm ID pipeline with and without a drag reducing aqueous polymer solution are presented. Data were obtained for sphere- to-pipe diameter ratios of 0.74 and 0.925 with polymer concentrations of 0, 25, 50, and 100 wppm over a Reynolds number range of 1633 to 29400 for single spheres and trains of up to three spheres rigidly connected. It was found that relatively dilute polymer solutions can considerably affect the separation angle. Furthermore, that the angle is dependent on the diameter ratio, number of spheres in a train, the Reynolds number, and the polymer concentration, and at a given diameter ratio and concentration the angle of separation can be correlated as a function of the Reynolds number. The data substantiate a previous hypothesis by Latto, that the observed drag increase of spheres in a pipeline caused by polymer addition, is due to an increase of the separation angle and therefore an increase in the form or pressure drag

Effect of Dilute Polymer Solutions on External Boundary Layers

The paper reports an experimental study of the flow of homogeneous aqueous polyacrylamide MRL 402 solution over a thin flat plate. Extensive velocity profile data were obtained, using both cylindrical and conical hot-file probes, and used to obtain local skin friction profiles. Direct drag measurements were made over a period of time for concentrations of 0, 25, 50 and 75 wppm and indicated that there was no appreciable degradation of the polymer. Extensive turbulence intensity data were obtained which were contradictory but indicated that the conical type probe is better than the cylindrical type for turbulence measurements and that the turbulence intensity reduced as the fluid progressed along the surface. Results indicate that the form drag is reduced but that the viscous drag is not reduced unless an onset friction velocity is exceeded, which was found to be 0.074 ft/sec for the polymer used

Environmental guidelines for new and existing piggeries

These guidelines apply to the management of Western Australia piggeries in Western Australia, including intensive Growing pigs under intensive conditions where the and extensive operations, straw-based housing and animals spend their entire life cycle indoors, is an combinations of these (otherwise referred to as semi- important part of the Western Australian and intensive housing).https://researchlibrary.agric.wa.gov.au/bulletins/1037/thumbnail.jp

Becoming-with response-ability: How does diffracting posthuman ontologies with multi-modal sensory ethnography spark a multiplying femifesta/manifesta of noticing, attentiveness and doings in relation to mundane politics and more-than-human pedagogies of response-ability?

Our collective, sensorial, cartographic storying of becoming-response-able traces our noticing, attentiveness and doings with everyday materialities. We take four objects as a provocation for knowledge-ing with sensorial ethnographic assemblages that includes spaghetti, carpet, a toilet stall and a pair of binoculars. Through diffracting ideas of multimodality with posthuman ontologies, we experiment with sensory more-than-human intra-activities. We share our embodied encounters and experiments with materiality and the discourses that shape it through the lens of mundane politics. We hope to offer alternative ways of thinking with and doing research in educational contexts and explore how these sensory thinking-doing-feelings have repositioned our attentiveness and future orientation to a multiplying femifesta/manifesta of everyday noticing, doings and becoming-with pedagogies of response-ability

Manipulation of Pre-Target Activity on the Right Frontal Eye Field Enhances Conscious Visual Perception in Humans

The right Frontal Eye Field (FEF) is a region of the human brain, which has been consistently involved in visuo-spatial attention and access to consciousness. Nonetheless, the extent of this cortical site’s ability to influence specific aspects of visual performance remains debated. We hereby manipulated pre-target activity on the right FEF and explored its influence on the detection and categorization of low-contrast near-threshold visual stimuli. Our data show that pre-target frontal neurostimulation has the potential when used alone to induce enhancements of conscious visual detection. More interestingly, when FEF stimulation was combined with visuo-spatial cues, improvements remained present only for trials in which the cue correctly predicted the location of the subsequent target. Our data provide evidence for the causal role of the right FEF pre-target activity in the modulation of human conscious vision and reveal the dependence of such neurostimulatory effects on the state of activity set up by cue validity in the dorsal attentional orienting network

New approaches to the study of human brain networks underlying spatial attention and related processes

Cognitive processes, such as spatial attention, are thought to rely on extended networks in the human brain. Both clinical data from lesioned patients and fMRI data acquired when healthy subjects perform particular cognitive tasks typically implicate a wide expanse of potentially contributing areas, rather than just a single brain area. Conversely, evidence from more targeted interventions, such as transcranial magnetic stimulation (TMS) or invasive microstimulation of the brain, or selective study of patients with highly focal brain damage, can sometimes indicate that a single brain area may make a key contribution to a particular cognitive process. But this in turn raises questions about how such a brain area may interface with other interconnected areas within a more extended network to support cognitive processes. Here, we provide a brief overview of new approaches that seek to characterise the causal role of particular brain areas within networks of several interacting areas, by measuring the effects of manipulations for a targeted area on function in remote interconnected areas. In human participants, these approaches include concurrent TMS-fMRI and TMS-EEG, as well as combination of the focal lesion method in selected patients with fMRI and/or EEG measures of the functional impact from the lesion on interconnected intact brain areas. Such approaches shed new light on how frontal cortex and parietal cortex modulate sensory areas in the service of attention and cognition, for the normal and damaged human brain

The Ocean Carbon States Database: a proof-of-concept application of cluster analysis in the ocean carbon cycle

In this paper, we present a database of the basic regimes of the carbon cycle in the ocean, the ocean carbon states, as obtained using a data mining/pattern recognition technique in observation-based as well as model data. The goal of this study is to establish a new data analysis methodology, test it and assess its utility in providing more insights into the regional and temporal variability of the marine carbon cycle. This is important as advanced data mining techniques are becoming widely used in climate and Earth sciences and in particular in studies of the global carbon cycle, where the interaction of physical and biogeochemical drivers confounds our ability to accurately describe, understand, and predict CO2 concentrations and their changes in the major planetary carbon reservoirs. In this proof-of-concept study, we focus on using well-understood data that are based on observations, as well as model results from the NASA Goddard Institute for Space Studies (GISS) climate model. Our analysis shows that ocean carbon states are associated with the subtropical–subpolar gyre during the colder months of the year and the tropics during the warmer season in the North Atlantic basin. Conversely, in the Southern Ocean, the ocean carbon states can be associated with the subtropical and Antarctic convergence zones in the warmer season and the coastal Antarctic divergence zone in the colder season. With respect to model evaluation, we find that the GISS model reproduces the cold and warm season regimes more skillfully in the North Atlantic than in the Southern Ocean and matches the observed seasonality better than the spatial distribution of the regimes. Finally, the ocean carbon states provide useful information in the model error attribution. Model air–sea CO2 flux biases in the North Atlantic stem from wind speed and salinity biases in the subpolar region and nutrient and wind speed biases in the subtropics and tropics. Nutrient biases are shown to be most important in the Southern Ocean flux bias. All data and analysis scripts are available at https://data.giss.nasa.gov/oceans/carbonstates/ (DOI: https://doi.org/10.5281/zenodo.996891)