Laboratory studies of till deformation with implications for the motion and sediment transport of the Lake Michigan Lobe

Glacier motion and sediment transport are attributed commonly to pervasive shearing of subglacial till to high strains (the bed-deformation hypothesis). However, the processes that control bed deformation are difficult to observe beneath modern glaciers, and observations of the geologic record have not been sufficient to determine whether tills have been sheared to the high strains required by this hypothesis;The shear strength of the ice-till interface controls whether a glacier slips over its bed or shears it pervasively over much of its thickness. When clasts gripped by basal ice plow through the bed, the ice-till interface is weakened. Results of experiments using a ring-shear device in which hemispheres were pushed through water-saturated till indicate a progressive decrease in resistive force on hemispheres with increasing plowing speed. This effect is due to the generation of high pore-water pressures in front of the hemispheres at fast plowing speeds (e.g. 380 m y-1), which weakens till and reduces resistive forces. These results indicate that increases in glacier sliding speed will reduce resistive forces exerted by till on plowing clasts, which will promote decoupling of the ice from the bed and inhibit pervasive bed deformation. In addition, this positive pore-pressure feedback may constitute a flow instability that promotes fast glacier flow;The ring-shear device was also used to develop criteria at microscopic scales for identifying highly sheared tills. Results of experiments indicate that the alignment (fabric) of elongate, sand-sized particles becomes strong at high strains. Furthermore, microshears become more abundant and align progressively with the shearing direction as strain increases. Magnetic fabrics calibrated to strain in an ancillary ring-shear study and sand-particle fabrics were used to test the till-deformation model as applied to the Batestown advance of the Lake Michigan Lobe. Results indicate that magnetic and sand-particle fabrics are not sufficiently strong to support the bed-deformation model. Furthermore, consistent changes in fabric direction with depth and fabric patterns around cobbles and small boulders indicate that the till likely sheared only in thin zones near the glacier sole during till accretion to the bed from ice. Bed shearing likely contributed only minimally to sediment transport

Not all jellyfish are equal: isotopic evidence for inter- and intraspecific variation in jellyfish trophic ecology

Jellyfish are highly topical within studies of pelagic food-webs and there is a growing realisation that their role is more complex than once thought. Efforts being made to include jellyfish within fisheries and ecosystem models are an important step forward, but our present understanding of their underlying trophic ecology can lead to their oversimplification in these models. Gelatinous zooplankton represent a polyphyletic assemblage spanning >2,000 species that inhabit coastal seas to the deep-ocean and employ a wide variety of foraging strategies. Despite this diversity, many contemporary modelling approaches include jellyfish as a single functional group feeding at one or two trophic levels at most. Recent reviews have drawn attention to this issue and highlighted the need for improved communication between biologists and theoreticians if this problem is to be overcome. We used stable isotopes to investigate the trophic ecology of three co-occurring scyphozoan jellyfish species (Aurelia aurita, Cyanea lamarckii and C. capillata) within a temperate, coastal food-web in the NE Atlantic. Using information on individual size, time of year and δ 13 C and δ 15 N stable isotope values, we examined: (1) whether all jellyfish could be considered as a single functional group, or showed distinct inter-specific differences in trophic ecology; (2) Were size-based shifts in trophic position, found previously in A. aurita, a common trait across species?; (3) When considered collectively, did the trophic position of three sympatric species remain constant over time? Differences in δ 15 N (trophic position) were evident between all three species, with size-based and temporal shifts in δ 15 N apparent in A. aurita and C. capillata. The isotopic niche width for all species combined increased throughout the season, reflecting temporal shifts in trophic position and seasonal succession in these gelatinous species. Taken together, these findings support previous assertions that jellyfish require more robust inclusion in marine fisheries or ecosystem models

Natural stream restoration and enhancement

The Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311.Biosystems and Agricultural Engineerin

Per-plexus: Engaging Slippages of Socio-Spatial Awareness

This thesis investigates the role of architecture upon the perception of its subject. It is particularly concerned with the perceptual “flickers” that result when the subject is confronted with simultaneous and opposed socio-spatial phenomena. It asserts that when the subject is confronted with such phenomena, a single state flickers to the foreground while all others recede to the background of perception, causing the subject not only to recontextualize socio-spatial awareness in light of the foregrounded state, but also to labor in order to totalize the sum of all states. Ultimately, this thesis is interested in activating the subject and creating an experience that is not defined physically but rather perceptually, not accessible through instant apprehension but rather through labored comprehension. It tests these assertions and advances these interests by speculating on a living center that foregrounds the impact of geometry and form on the subject’s perception of private and public

Development of an Experimental Waste Framework Based on Bim/Lean Concept in Construction Design

The construction industry faces many problems and challenges especially with the construction of housing which are due to the high level of non-value-adding activities (waste) that reduce the overall construction performance and productivity. In recent years, there have been investigations and research on improving the performance of construction. Lean construction is widely known as an effective process which aims to maximise customer value and the efficiency of the project by eliminating non-value-adding activities or waste. Moreover, the Building Information modelling (BIM) concept has been recognised as a collaborative process which aims to improve the overall project performance through its tools' capabilities. This paper intends to study the potential effects of integrating these two concepts in order to reduce construction waste. This paper presents a framework, named an Experimental Waste Framework based on the findings of this paper to explore how an integrated BIM and Lean concept can contribute to the practicable reduction of construction waste in the design process of construction

Gaze-supported gaming: MAGIC techniques for first person shooters

MAGIC--Manual And Gaze Input Cascaded-pointing techniques have been proposed as an efficient way in which the eyes can support the mouse input in pointing tasks. MAGIC Sense is one of such techniques in which the cursor speed is modulated by how far it is from the gaze point. In this work, we implemented a continuous and a discrete adaptations of MAGIC Sense for First-Person Shooter input. We evaluated the performance of these techniques in an experiment with 15 participants and found no significant gain in performance, but moderate user preference for the discrete technique

Stellar clustering and the kinematics of stars around Collinder 121 using Gaia DR3

We study the region around Collinder 121 (Cr 121) using newly available 6-dimensional data from the Gaia DR3 catalogue. Situated in the third quadrant, near the galactic plane, Collinder 121 lies in the region of Canis Major centred around l = 236 degrees, b = -10 degrees. Previous studies have suggested that the stellar associations in this region comprise an OB association (CMa OB2) lying at about 740 pc with a more distant open cluster (Cr 121) at approximately 1170 pc. Despite these studies, the precise nature of Collinder 121 remains uncertain. This study investigates the region bounded by the box l = 225 to 245 degrees, b = 0.00 to -20.00 degrees to a depth of 700 pc from 500 to 1200 pc which fully encompasses the region discussed in the literature. Using Gaia DR3 data, we do not find associations at the distances given in the literature. Instead, using the HDBSCAN machine learning algorithm, we find a major association of OB stars centred around 803 pc. Within this association we find four smaller subgroups that may be indicative of a larger association and which are located at a mean distance of 827 pc. Proper motion studies find coherence between these four subgroups and show a distinctive east to west increase in the size of the velocity vectors which supports contemporary studies that show similar trends in OB populations in Cygnus and within the Carina spiral Arm. Therefore, we hypothesize that Cr 121 and CMa OB2 are the same cluster, consistent with the 1977 study by Hoogerwerf

Sensing and Active Flow Control for Advanced BWB Propulsion-Airframe Integration Concepts

In order to realize the substantial performance benefits of serpentine boundary layer ingesting diffusers, this study investigated the use of enabling flow control methods to reduce engine-face flow distortion. Computational methods and novel flow control modeling techniques were utilized that allowed for rapid, accurate analysis of flow control geometries. Results were validated experimentally using the Techsburg Ejector-based wind tunnel facility; this facility is capable of simulating the high-altitude, high subsonic Mach number conditions representative of BWB cruise conditions

Understanding the Effects of Wind Intensity, Forward Speed, Pressure and Track on Generation and Propagation of Hurricane Irma Surges around Florida

In this study, it is demonstrated that hurricane wind intensity, forward speed, pressure, and track play an important role on the generation and propagation of coastal storm surges. Hurricane Irma, which heavily impacted the entire Florida peninsula in 2017, is used to study the storm surge sensitivity to varying storm characteristics. Results show that the west coast experiences a negative surge due to offshore wind of the approaching storm, but the positive surge returns after the hurricane eye passes over a location and wind became onshore. In the west coast peak, surges are intensified by an increase in onshore wind intensity and forward speed. In the Florida Keys, peak surges are intensified by an increase in wind intensity, a decrease in forward speed and a decrease in pressure. In southeast and east Florida, peak surges are intensified by decrease in pressure, although overall surges are less significant as the water can slide along the coastline. In the recessed coastline of Georgia-Carolinas, maximum surge is elevated by an increase in onshore wind intensity. Shifting the track westward increases peak surges on the west coast, while shifting the track eastward increases peak surge on the east coast. The results demonstrate a new understanding about the sensitivity of surge to varying parametric conditions and the importance of considering changes in the coastline orientation in storm surge predictions

Portraying the hosts: Stellar science from planet searches

Information on the full session can be found on this website: https://sites.google.com/site/portrayingthehostscs18/We present a compendium of the splinter session on stellar science from planet searches that was organized as part of the Cool Stars 18 conference. Seven speakers discussed techniques to infer stellar information from radial velocity, transit and microlensing data, as well as new instrumentation and missions designed for planet searches that will provide useful for the study of the cool stars