4,425 research outputs found
What’s a Federalist to Do? The Impending Clash Between Textualism and Federalism in State Congressional Redistricting Suits Under Article 1, Section 4
Nanofluids (NFs) are nanotechnology-based colloidal dispersion prepared by dispersing nanoparticles (NPs) in conventional liquids, as the base liquid. These advanced fluids have displayed potential to enhance the performance of conventional heat transfer fluids. This work aims at providing an insight to the field of NFs by investigating in detail the fabrication and evaluation of physico-chemical, thermo-physical and heat transfer characteristics of NFs for practical heat transfer applications. However, in order to utilize NFs as heat transfer fluids in real applications there are some challenges to overcome. Therefore, our goal is not only to optimize the thermo-physical properties of NFs with the highest thermal conductivity (TC) and minimal impact of NPs on viscosity, but also on preparing NFs with good stability and the best heat transfer performance. In the first stage, detailed studies were carried out to engineer NFs with good stability and optimal thermo-physical properties. In this work we investigated the most important factors, and the dependence of thermo-physical properties of NFs, including NP composition and concentration, NF stability, surface modifiers, particle size (NP size and particle with micron size), NF preparation method (two-step vs one-step method) and base liquid was studied. We also demonstrated, for the first time, the role of crystal structure, exemplified by alpha- and beta- SiC particles, on thermo-physical properties of NFs. For these purposes several NFs were fabricated using different nanostructured materials and various base liquids by one-step and two-step methods. An optimization procedure was designed to keep a suitable control in order to reach the ultimate aim where several stages were involved to check the desired characteristics of each NF system. Among several NFs systems studied in the first stage evaluation, a particular NF system with 9 wt% concentration, engineered by dispersing SiC NPs with alpha- crystal structure in water/ethylene glycol as based liquid exhibited the optimal thermo-physical properties. This NF was the only case which could pass the all criteria involved in the optimization procedure by exhibiting good stability, TC enhancements of ~20% with only 14% increase in viscosity at 20 oC. Therefore, this engineered NF was considered for next phase evaluation, where heat transfer coefficient (HTC) tests were designed and carried out to evaluate the thermal transport property of the selected alpha- SiC NF. A HTC enhancement of 5.5% at equal pumping power, as realistic comparison criteria, was obtained indicating the capability of this kind of NFs to be used in industrial heat transfer applications. These findings are among the few studies in the literature where the heat transfer characteristics of the NFs were noticeable, reproducible and based on a realistic situation with capability of commercializing as effective heat transfer fluid. QC 20140416Nanohe
Religious experience: a sociological perspective
The usual idea of a religious experience is conceived in largely individual terms. It is
generally seen as an uninduced, unanticipated and most probably sudden sense of some
force, power, or mood which transcends everyday comprehension, and which is beyond
ordinary empirical explanation. Where an explanation of such phenomena is attempted, the
tendency is to seek to understand them in essentially psychological terms. What I wish to
suggest is that, although this is the common understanding of what is implied by the term
“religious experience”, in fact by no means all such experience is of a purely psychological
kind. Many people, who would not claim to have encountered such a numinous sense of a
force or a presence, would certainly claim to have acquired new religious insight by quite
different means and in what would usually be quite different circumstances
Geology of the Oak Cliff Quadrangle, Dallas County, Texas
Consolidated marine rocks of the Oak Cliff Quadrangle belong to a portion of the Upper Cretaceous Austin formation. On the basis of lithology the formation is divided into a lower chalk and a middle marl. Buried channels, some 6 feet deep and 95 feet across, occur in the lower chalk. They result from submarine scouring, indicating that deposition was not a continuous process. Bentonite seams, some as much as 6 inches thick, occur at various horizons in the lower chalk, pointing to periodic volcanic activity. Numerous small normal faults in the Austin formation may have resulted from differential compaction of the underlying, incompetent, Eagle Ford shale. Unconsolidated Quaternary alluvial deposits occur along the Trinity river, with terrace surfaces approximately 110, 65, and 26 feet above the floodplain. The terrace material consists of reworked chalk and marl, foraminiferal sands, silts, sands, and gravel
Evaluation of Herbicides on the Establishment of Pearl Millet [Pennisetum glaucum (L.) R. Br.] x Napiergrass (Pennisetum purpureum Schumach.)
Pearl millet [Pennisetum glaucum (L.) R. Br.] x napiergrass (Pennisetum purpureum Schumach.) (PMN) hybrids have potential as a seeded, perennial bioenergy or forage crop. The PMN hybrid utilized in this study (PMN10TX13) was developed as an alternative to herbaceous bioenergy feed stocks that either require vegetative propagation, complicated planting strategies due to small seed size, or annual reseeding due to annual growth habit. However, PMN seedlings are impacted by competition from nearby weeds for water, nutrients, and sunlight during establishment. To date, there is limited agronomic information on strategies for effective establishment of weed-free PMN stands. The objective of this study was to develop herbicide response tests to determine the phytotoxic effects of selected pre-crop emergence (PRE) and post-crop emergence herbicides (POST) on the seeded establishment of PMN. Several herbicides with utility for weed free establishment of seeded PMN were successfully identified. Pre-emergent herbicides Balance Pro (isoxaflutole), Dual II (s-metolachlor,) Plateau (imazapic), and Permit (halosulfuron) were effective as long as sufficient rates of seed safener were used. Post-crop emergent herbicides Permit (halosulfuron), Prowl (pendimethalin), Banvel (dicamba), Aatrex (atrazine), AIM (carfentrazone-ethyl), Warrant (achetochlor), and Huskie (pyrasulfotole) were also found to be safe for use at the 5-7 leaf stage and beyond
Role of West Virginia School Psychologists in a Response to Intervention Framework
With the passage of No Child Left Behind in 2001, schools were required to prepare students using research-based teaching methods, interventions, and approaches. Response to Intervention (RTI) is an evidence-based practice that allows schools to assess student responses to interventions. RTI was implemented as a pilot program in West Virginia beginning from 2007 to 2010. Although research has been frequent on implementing RTI, little research has been conducted analyzing RTI and school psychologist involvement, particularly in West Virginia. The purpose of this study was to examine what factors serve as predictors of RTI involvement in West Virginia. The examiner used data from the 2011 West Virginia School Psychologists Association survey to predict RTI Involvement by West Virginia school psychologists. The results indicated no variables significantly predict RTI involvement for West Virginia school psychologists
Cumbrian alchemy
To coincide with the Cumbrian Alchemy exhibition (Rheged Centre, Penrith, UK from February to April 2014), a lavishly illustrated book is launched. Designed by the artist James Brook, it brings together material from the Cumbrian Alchemy project with essays by eminent professionals in the field in an enquiry into the place, the spaces, the people and the monuments of the region. Essayists include the archaeologist David Barrowclough from the University of Cambridge, an expert on the prehistory of Lancashire and Cumbria who considers the concept of deep-time in Cumbria and the future archaeology of long term storage of nuclear waste. Nuclear specialist Paul Abraitis investigates the natural history of radiation in the region, whilst Cumbrian journalist Alan Cleaver provides insights into the folklore of ‘places of power’ in Cumbria
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Investigation of static zones and wall slip through sequential ram extrusion of contrasting micro-crystalline cellulose-based pastes
The shape and size of static regions in the extrusion flow of a viscoplastic material through axisymmetric square entry dies was studied experimentally using a simple flow field analysis technique. A white micro-crystalline cellulose/water paste was extruded sequentially with a graphite-stained black analogue paste, revealing static regions in the corners of the system extending less than 30% of the barrel radius into the centre of the channel. Slow (relative to the bulk) slip flow along the die face was evident in the experiments, implying the existence of a stick-slip transition on this surface.
Finite element simulations using the Papanastasiou regularised Bingham plastic viscosity model and the linear Navier wall slip law were found to reproduce the experimental results poorly, capturing only separately the slip dominated bulk flow and the static corner region for different values of the slip coefficient _. The effect of severe wall slip was to reduce the distinction between unyielded and yielded material making the definition of the yield surface challenging. Investigation and implementation of a stick-slip wall condition is believed to be required for further work in this area.This is the author's accepted manuscript. The final version is available from Elsevier in the Journal of Non-Newtonian Fluid Mechanics here: http://www.sciencedirect.com/science/article/pii/S0377025714001207
Flow visualisation and modelling of solid soap extrusion
Ram extrusion of a solid granular soap was studied using three geometrically identical but differently-scaled extruders. The experimental design revealed deviation from the Benbow and Bridgwater (1993) extrusion model due to nonideal, scale-dependent effects. Typically these effects, linked to the shear rate in the extruder, are absorbed into the model's material pseudo-properties. The data were able to be represented using the Basterfield et al. (2005) model for extrusion flow which does include a shear rate as a variable. Flow visualisation in conjunction with fluid dynamics-based simulations showed, however, that the assumptions underlying the Basterfield et al. model are not appropriate for soap extrusion, despite the good agreement of the model with the experimental extrusion data. This highlights a need for care in interpretation of extrusion data, in that the limited information gathered about any given experiment, typically just the extrusion pressure, can lead to the generation of spurious parameters if the wrong model is applied.This work was funded by Ceratizit GmbH Austria and Sandvik Hyperion U
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