Unsteady three-dimensional simulation of VTOL upwash fountain turbulence

Numerical simulations of a planar turbulent wall jet and a planar VTOL upwash fountain were performed. These are three dimensional simulations which resolve large scale unsteady motions in the flows. The wall jet simulation shows good agreement with experimental data and is presented to verify the simulation methodology. Simulation of the upwash fountain predicts elevated shear stress and a half velocity width spreading rate of 33% which agrees well with experiment. Turbulence mechanisms which contribute to the enhanced spreading rate are examined

Extraction in four dimensions:time, space and the emerging geo(-)politics of deep sea mining

Despite the truism that less is known about the deep-sea than outer space, deep-sea mining (DSM) is being promoted as the next frontier of resource extraction. In 2019, Nautilus Minerals hopes to become the world’s first company to mine the deep seabed in the waters off Papua New Guinea (PNG). DSM thus stands at the threshold of becoming a matter of politics; it has provoked a wide range of geopolitical imaginaries variously relating to ‘resource security’ and ‘progress’, on the one hand, and environmental disaster and precaution on the other. However, these accounts do little to address the specific ‘nature’ of the deep-sea, seabed and their extreme location and materialities, and are instead framed by classic geopolitical concerns with interstate relations. Against this background and illustrated by examples centred on PNG, this paper argues that future engagements with the geopolitics of DSM are more accurately conceptualised by an engagement with time as well as three dimensional space. This includes the multiple spatial and temporal registers through which both the geology and ecologies of seabed and seawater operate. By highlighting the importance of resource temporalities, it suggests that the geopolitics of both DSM and extraction in extreme places more generally is not only spatially complex, it is also a matter of time

Newspaper matrix backing techniques.

The problem of developing suitable materials and techniques for the elimination of hand backing of mats was undertaken. A thermosetting resin of the resorcinol type, ad-mixed with 15 to 25 per cent short-fiber asbestos, was applied to the mats both as a paste and in the form of a partially cured resin sheet. Its use was discontinued since its inherent insulating properties and warpage were found to be undesirable. After experimenting with several other backing materials and methods, the following procedure was concluded to be feasible: (1) Spraying sodium silicate solution upon a sheet of blotting paper. (2) Pressing the glue-coated blotting paper to the mat during the pressing of the mat upon the chase. (3) Warming to set the glue. (4) Sanding excess blotting paper off high portion of mat back. (5) Final drying in Sta-hi vacuum driers. A sanding unit was designed and constructed to remove the backing from the raised portions of the mat. In an effort to replace the present day dry mat with one requiring no backing, the following materials were chosen and tried as mat substitutes: Aluminum sheet, lead-aluminum laminates, Teflon, ethyl cellulose, resorcinol, and several layers of the moistened, conventional mat

Problematic Social Media Use: Are There Gender Differences in Control and Craving

Problematic social media use is characterized by being overly concerned about social media, having an uncontrollable urge to use social media, and devoting ample amounts of time to social media that impairs other important life areas. According to Statista, 15% of people from 23-38 years of age admit they demonstrate problematic social media use, and 30% of all the participants surveyed admit they somewhat demonstrate problematic social media use. Problematic social media use is a growing problem, especially during a time where the world took a momentary pause and people turned to social media during quarantine amidst the pandemic. The Bergen Social Media Addiction Scale (BSMAS) has been widely used to measure this problematic behavior. This is a short six item scale measuring one factor, overall social media addiction. The goal of the current study was to create a new scale based on the BSMAS and the validated Internet Addiction Test-Short Version (s-IAT). The s-IAT is a 12 item scale that measures Internet addiction with the two factors control and craving. The scale was sent to 361 participants, both males and females to see whether or not there are gender differences. Our findings show that the DePauw Social Media Scale does measure problematic social media use and captures the two factors control and craving. There were gender differences in control, where females were higher than males, but not in craving. Our findings reveal that the relationship between gender and problematic social media use may differ from gender and Internet addiction

Utilization and Land Cover Examined in Two Blue Earth County Streams

Examining soil mapping units of the United States Agriculture department\u27s Soil Conservation Service for comparison with land usage In the Blue Earth River valley, this study found that seven of 56 units in the valley accounted for 76.5 percent of the study terrain. Agricultural use or non-use of the land units matched established . designations. The Le Sueur River flows for about 40 miles within Blue Earth county of south ·central Minnesota. Land cover in the valley, as determined by stereoscopic examination of aerial photographs, shows forest on 65 percent, agriculture on 22 percent, and other cover on 13 percent of the land. This differs significantly from findings of an earlier study of the Blue Earth River in the same county

Contextuality in Measurement-based Quantum Computation

We show, under natural assumptions for qubit systems, that measurement-based quantum computations (MBQCs) which compute a non-linear Boolean function with high probability are contextual. The class of contextual MBQCs includes an example which is of practical interest and has a super-polynomial speedup over the best known classical algorithm, namely the quantum algorithm that solves the Discrete Log problem.Comment: Version 3: probabilistic version of Theorem 1 adde