996 research outputs found
Supplemental Material - Estimation of Subjectively Reported Trust, Mental Workload, and Situation Awareness Using Unobtrusive Measures
No full textSupplemental Material for Estimation of Subjectively Reported Trust, Mental Workload, and Situation Awareness Using Unobtrusive Measures by Jacob R. Kintz, Neil T. Banerjee, Johnny Y. Zhang, Allison P. Anderson, and Torin K. Clark in Human Factors.</p
Boron and chlorine contents of upper oceanic crust: basement samples from IODP Hole 1256D
No full textBoron, Cl, Ti, K, Sm, and Gd concentrations of oceanic crust samples were determined by prompt gamma neutron activation analysis. The samples include 63 basalts and 5 gabbros obtained at various depths (369–1503 m below seafloor) from Hole 1256D during Ocean Drilling Program Leg 206 and Integrated Ocean Drilling Program Expedition 309 and 312. The results show stepwise downhole variations, B content and B/K decrease, and Cl content and Cl/K increase with increasing depth. High B content (>1.5 ppm) in shallower rocks (extrusive lavas) is probably achieved by low-temperature seawater alteration, and high Cl contents (up to 1400 ppm) in the deeper rocks (plutonic section) would show result of high-temperature hydrothermal alteration. Average B and Cl values for the upper oceanic crust in Hole 1256D are 1.5 ppm and 334 ppm, respectively
Real-space Manifestations of Bottlenecks in Turbulence Spectra
No full textAn energy-spectrum bottleneck, a bump in the turbulence spectrum between the inertial and dissipation ranges, is shown to occur in the non-turbulent, one-dimensional, hyperviscous Burgers equation and found to be the Fourier-space signature of oscillations in the real-space velocity, which are explained by boundary-layer-expansion techniques. Pseudospectral simulations are used to show that such oscillations occur in velocity correlation functions in one- and three-dimensional hyperviscous hydrodynamical equations that display genuine turbulence
Design and testing of a thick-film dual-modality sensor for composition measurements in heterogeneous mixtures
No full textThe current paper focuses on design and laboratory evaluation of a dual-modality sensor, developed for the needs of oil and gas extraction industry to measure the composition of heterogeneous mixtures in harsh conditions. The sensor combines ultrasonic and electrical measurement techniques, which are non-destructive, rapid and can potentially provide an on-line industrial measurement. Such a ‘dual-modality’ measurement could potentially be reliable in a wider range of process conditions. A distinct feature of the sensors presented here is their construction, which makes use of the thick-film technology, enabling the construction of multi-layered structures of both conductive and non-conductive layers, some of which may exhibit piezoelectric properties for ultrasonic measurement purposes. These are later fired on a ceramic substrate to provide rugged sensors, capable of working in aggressive industrial environments. Laboratory experiments to investigate the feasibility of the dual-modality sensors were conducted and some comparisons with the theoretical predictions are presented
Origin of the sheeted dike complex at superfast spread East Pacific Rise revealed by deep ocean crust drilling at Ocean Drilling Program Hole 1256D
No full textSuperfast spread (22 cm/a) upper oceanic crust drilled at Ocean Drilling Program site 1256 comprises a thick sequence of extrusive lavas underlain by a thin region of sheeted dikes. The sheeted dikes at this site are characterized by the intimate association of in situ hyaloclastic fragmentation and hydrothermal alteration. Lithostatic and magmastatic pressure estimates reveal that there is no effective level of neutral buoyancy within the extrusive layer to trap dikes in the crust. This results in a situation that favors the extrusion rather than intrusion of magma. Fractures created by magmas rising in dikes were the loci of intense hydrothermal circulation and provided the pathways for subsequent dike intrusions. Magma-rich conditions expected for fast spreading ridge segments give rise to a rapid increase in magmatic pressure, which can result in dike intrusion even under only small deviatoric stress. This allows for the emplacement of narrow dikes in the upper crust, with magmas more likely to extrude, and hence the high extrusive/intrusive ratio for Site 1256. <br/
Attempted formulation of nutraceutical grade double emulsions using a simple bench-top protocol
No full text['This presentation explores something other than the conference theme.']Viable, Healthy and Safe CommunitiesDESIGN AND CREATION OF OPTIMIZED DOUBLE EMULSIONSJ. Neil, R. Salama, Dr. A. Banerjee, and Prof. J. F. TrantDouble emulsions, containing multiple phases embedded within each other, are unique systems because they allow us to combine hydrophilic and lipophilic components with complementary functionalities within the same emulsion droplet. In this study, we attempt to repurpose the method used by Wang et al. to create single-cored perfluorinated oil double emulsions in water, for the generation of cannabinoid double emulsions. THC or CBD dissolved in carrier lipids with a range of density and viscosity values was used as the lipid phase in these experiments.. The double emulsions were created by initially preparing a water-in-oil emulsion, which was then pipetted into a secondary aqueous phase, and vortexed to produce the final double emulsion (Wang et al., 2021). The emulsions thus produced were analyzed and examined under an optical microscope. While double emulsions were, in fact, created, they all contained multiple cores embedded within a single shell, and were unstable to storage over a period of days, thus confirming that this method is unlikely to succeed in cases where either the lipid or the aqueous phase is made to carry an API. While careful matching of density and viscosity of both phases might produce a solution to this problem, it is unlikely that this protocol will have widespread applicability over a library of APIs. Wang, J., Hahn, S., Amstad, E., & Vogel, N. (2021). Tailored double emulsions made simple. Advanced Materials, 34(5), 2107338. https://doi.org/10.1002/adma.20210733
Composition of hydrothermal fluids and mineralogy of associated chimney material on the East Scotia Ridge back-arc spreading centre
No full textThe East Scotia Ridge is an active back-arc spreading centre located to the west of the South Sandwich island arc in the Southern Ocean. Initial exploration of the ridge by deep-tow surveys provided the first evidence for hydrothermal activity in a back-arc setting outside of the western Pacific, and we returned in 2010 with a remotely operated vehicle to precisely locate and sample hydrothermal sites along ridge segments E2 and E9. Here we report the chemical and isotopic composition of high- and low-temperature vent fluids, and the mineralogy of associated high-temperature chimney material, for two sites at E2 (Dog’s Head and Sepia), and four sites at E9 (Black & White, Ivory Tower, Pagoda and Launch Pad). The chemistry of the fluids is highly variable between the ridge segments. Fluid temperatures were ∼350 °C at all vent sites except Black & White, which was significantly hotter (383 °C). End-member chloride concentrations in E2 fluids (532 - 536 mM) were close to background seawater (540 mM), whereas Cl in E9 fluids was much lower (98 - 220 mM) indicating that these fluids are affected by phase separation. Concentrations of the alkali elements (Na, Li, K and Cs) and the alkaline earth elements (Ca, Sr and Ba) co-vary with Cl, due to charge balance constraints. Similarly, concentrations of Mn and Zn are highest in the high Cl fluids but, by contrast, Fe/Cl ratios are higher in E9 fluids (3.8 – 8.1 × 10−3) than they are in E2 fluids (1.5 - 2.4 × 10−3) and fluids with lowest Cl have highest Cu. Although both ridge segments are magmatically inflated, there is no compelling evidence for input of magmatic gases to the vent fluids. Fluid δD values range from 0.2 to 1.5 ‰, pH values (3.02 - 3.42) are not especially low, and F concentrations (34.6 - 54.4 μM) are lower than bottom seawater (62.8 μM). The uppermost sections of conjugate chimney material from E2, and from Ivory Tower and Pagoda at E9, typically exhibit inner zones of massive chalcopyrite enclosed within an outer zone of disseminated sulphide, principally sphalerite and pyrite, in an anhydrite matrix. By contrast, the innermost part of the chimneys that currently vent fluids with lowest Cl (Black & White and Launch Pad), is dominated by anhydrite. By defining and assessing the controls on the chemical composition of these vent fluids, and associated mineralisation, this study provides new information for evaluating the significance of hydrothermal processes at back-arc basins for ocean chemistry and the formation of seafloor mineral deposits
The Cassandras in Exile: A Study of the Diasporic Sensibility in the Poetry of Meena Alexander, Sujata Bhatt, Chitra Banerjee Divakaruni, Moniza Alvi and Jean Arasanayagam
No full textNot availabl
Super-growth of CNTs based on ZrN for TSV application
No full textThis thesis has explored the possibility of using carbon nanotubes (CNT) as a novel material for through-silicon vias (TSV) in 3D-integrated circuits. With the steady downscaling trend of the semiconductor industry, a major limiting factor to the overall performance of the device is the delay from interconnects; a trend that is worsening over successive technology nodes. As a remedy to this, the industry has been exploring the possibility of fabricating three dimensional integrated circuits, with shorter interconnect lengths (hence delay). Even then, the standard interconnect (or via) material, which is copper, poses a host of physical and technological challenges that constrain the development of this technology. The carbon nanotube is considered to be a promising alternative to copper, which can alleviate most of these problems. The thesis investigated the LPCVD growth of CNT on a novel substrate, with Fe as catalyst layer and ZrN as support layer. The combination of these two materials has the potential to support the growth of ultra-long CNT vias that are ideal for TSV applications. Before the successful growth of CNT, however, the right growth recipe had to be identified. For this purpose, a design-of-experiments approach was followed and the Taguchi method was used to optimize the recipes. Using optimized recipes for the highest length, CNT growth on continuous and patterned catalyst islands were carried out, resulting in a super-growth of ~ 900 µm in the first case, and ~ 200 µm in the second. The difference in magnitude and uniformity of the growth height for the two cases was studied, and it was understood how the size and distribution of the catalyst islands played an important role in CNT growth. When fabricating CNT-based interconnects, one should also have an idea about their electrical properties. An important property is the resistivity, which needs to be lower than copper. During this work, a recipe was designed which could grow CNT with the minimum resistivity. In order to achieve this, two equivalent circuit models were studied and a simple model was developed, which could calculate the CNT resistivity from their physical parameters (quality, density, diameter etc.). To measure the values of these parameters, a series of characterization experiments were performed on the growth samples, and their resistivities were calculated. Seeing that, these values were orders of magnitude higher than copper, new recipes were designed to increase the CNT growth density and quality. Using these, it was possible to decrease the CNT resistivity. Finally, the designed recipes were put to the test, when integration of CNT as TSV was attempted in a real 3D-IC prototype. Although not entirely successful, the growth results so obtained, gave an indication of how CNT growth in deep vias could be performed, and the TSV process made successful in the future.ECTMMicroelectronics & Computer EngineeringElectrical Engineering, Mathematics and Computer Scienc
Covalent organic frameworks and organic cage structures
No full textThe last 20 years have seen an enormous interest in research on the topic of crystalline porous framework materials, especially metal–organic frameworks (MOFs). MOFs exploit reversible metal–coordination chemistry to create extended, crystalline solids.1 However, a similar set of porous ordered covalent networks based on the reversible and modular connection of a vast array of rigid and symmetrical building blocks through covalent bonds has also emerged during this time. These materials, coined as “Covalent Organic Frameworks (COFs)”, have summoned considerable attention in the last decade, starting with a significant contribution from the Yaghi group,2 owing to their unique designing features as well as enormous potential.3 Like COFs, porous molecular crystals that are not interconnected by covalent bonding have also picked up significant research interest. Although these materials do resemble COFs, unlike COFs, they can be solution processable.4 For any structural chemists, these materials are excellent tools that can lead to more informed design processes and create a deeper understanding of how targeted porous extended structures should be made
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