2,412 research outputs found
Paper Based Testing vs. Mobile Device Based Testing in an EFL Environment: What’s the Difference?
Mobile devices are becoming increasingly more ubiquitous. This trend is especially true with
young people. An instructor’s job is to best service their students. If there are possible testing
means that are available, it is the responsibility of instructors to know if these mobile devices are as
capable of performing assessments as traditional paper and pencil tests. It is the purpose of this
research to evaluate if there is a difference in actual performance in Mobile Device Testing (MDT)
versus Paper Based Testing (PBT) and if there are any perceived differences. Participants (N=150) of
university EFL learners in South Korea were broken into groups, two different EFL tests were given,
the majority received PBT first followed by the MDT and the remaining performed the tests in
reverse order. Upon completion of both tests, the participants completed a survey evaluating both
testing mediums. Analysis of Variance (ANOVA), F-tests and t-tests were used to validate the
comparability of the two different EFL tests, check for overall correlation and test direct comparisons
of one group versus another. The results found that the tests were comparable in the performance
of the participants, there was no overall group that had a variance that could be attributed to the
testing medium, students perceived no difference in difficulty based on testing medium, and that
students actually preferred the MDT method over the PBT. These results indicate that MDT is a
viable alternative to PBT due to the comparability in performance and student motivational factors
Experimental Wear Modelling of Lifeboat Slipway Launches
It is necessary to use an inclined slipway to launch lifeboats in locations where there is no natural harbour. Slipway stations consist of an initial roller section followed by an inclined keelway, the lifeboat is released from the top of the slipway and proceeds under its own weight into the water. Contact is between the lifeboat keel and a lined, greased keelway and this that determines the friction along the slipway. This paper describes a bench test methodology to investigate this contact. The selection of a modified TE57 reciprocating tribometer and design of a modified pin on plate arrangement is discussed. A test schedule for both the original nickel/chromium coated steel lining and the new low-friction jute fibre/phenolic resin composite lining is developed to accurately reflect real world conditions including environmental contamination such as seawater or wind-blown sand. Environmentally conscious lubricants including water and bio-greases are investigated and compared for their effects in reducing slipway panel friction and wear. Experimental data is collected to establish wear mechanisms, wear volumes and friction characteristics for a range of lubricants and environmental contaminants for the two most common lifeboat keelway lining materials. Implications of this research for future lifeboat slipway design are discussed
Perceptions of fishers and developers on the co-location of offshore wind farms and decapod fisheries in the UK
The predicted expansion of the global offshore wind sector is likely to increase conflicts as users of the coastal zone compete for space, and the displacement of fisheries is of particular concern. It is therefore important to explore opportunities that could support the co-existence of offshore wind farms (OWFs) and fishing activity. In addition to ecological evidence on the effects of OWFs on commercially exploited species, the co-location issue requires understanding of the perceptions of fishers and OWF developers on key constraints and opportunities. Interviews were carried out in 2013 with 67 fishers in South Wales and Eastern England and with 11 developers from major energy companies, to discover experiences and opinions on the co-location of OWFs with crab and lobster fisheries. Developers expressed broad support for co-location, perceiving potential benefits to their relationship with fishers and their wider reputation. Fishers had more mixed opinions, with geographical variation, and exhibited a range of risk perception. The lack of reported experience of potting within OWFs was not related to stock concerns but to uncertainty around safety, gear retrieval, insurance and liability. Clear protocols and communication to address these issues are essential if co-location is to be feasible. Scale may also limit the potential benefits to fishers, especially in that large offshore OWFs are likely to be inaccessible to much of the inshore fleet. There remains the potential to enhance the artificial reef effects of OWFs by deploying additional material between the turbines, but options to finance such schemes, and how investment by OWF developers could be offset against compensation paid to displaced fishers, require further investigation
An Analysis of the First Ever DOW-Observed Mesolow
Embry-Riddle Aeronautical University Convective-Boundary Research Engaging Educational Student Experiences 2.0 (ERAU CBREESE 2.0) was a 15-day Doppler-on-Wheels (DOW) and Mobile Mesonet educational deployment from the Center for Severe Weather Research (CSWR). Building off the success of ERAU CBREESE in May 2015, the educational deployment was designed to observe and measure sea-breeze processes and convection, with a specific focus on Central Florida sub-regions that contain multiple mesoscale breezes and boundary collisions. On 6 July 2018, the first-ever DOW-observed mesolow was recorded along the Space Coast near Titusville, Florida. The purpose of this study was to examine the ability of the High-Resolution Rapid Refresh (HRRR) model to accurately diagnose and forecast this feature. After calculating the height of the DOW beam at each elevation scan, it was noted that the mesolow was predominantly observed in the 900–600-hPa layer. The 20 UTC HRRR analysis shows that the mesolow circulation was resolved by the model as it occurred. Since the HRRR explicitly diagnoses and forecasts many variables that other models, such as the Global Forecast System (GFS), are only able to parameterize, this also yielded the opportunity to explore what mechanisms may have contributed to the initial formation of the mesolow
The visual standards for the selection and retention of astronauts
Literature search with abstracts on visual performance standards for selection and retention of astronaut
Wear and Friction Modeling on Lifeboat Launch Systems
The RNLI provides search and rescue cover along the UK and RoI coast using a variety of lifeboats
and launch techniques. In locations where there is no natural harbour it is necessary to use a slipway
to launch the lifeboat into the sea. Lifeboat slipway stations consist of an initial section where the
boat is held on rollers followed by an inclined keelway lined with low friction composite materials,
the lifeboat is released from the top of the slipway and proceeds under its own weight into the water.
The lifeboat is later recovered using a winch line. It is common to manually apply grease to the
composite slipway lining before each launch and recovery in order to ensure sufficiently low friction
for successful operation. With the introduction of the Tamar class lifeboat it is necessary to upgrade
existing boathouses and standardise slipway operational procedures to ensure consistent operation.
The higher contact pressures associated with the new lifeboat have led to issues of high friction and
wear on the composite slipway linings and the manual application of grease to reduce friction is to be
restricted due to environmental impact and cost factors. This paper presents a multidisciplinary
approach to modelling slipway panel wear and friction using tribometer testing in conjunction with
finite element analysis and slipway condition surveys to incorporate common real-world effects such
as panel misalignments. Finally, it is shown that a freshwater lubrication system is effective,
reducing cost and environmental impacts while maintaining good friction and wear performance
Leukotrienes provide an NFAT-dependent signal that synergizes with IL-33 to activate ILC2s.
Group 2 innate lymphoid cells (ILC2s) and type 2 helper T cells (Th2 cells) are the primary source of interleukin 5 (IL-5) and IL-13 during type 2 (allergic) inflammation in the lung. In Th2 cells, T cell receptor (TCR) signaling activates the transcription factors nuclear factor of activated T cells (NFAT), nuclear factor κB (NF-κB), and activator protein 1 (AP-1) to induce type 2 cytokines. ILC2s lack a TCR and respond instead to locally produced cytokines such as IL-33. Although IL-33 induces AP-1 and NF-κB, NFAT signaling has not been described in ILC2s. In this study, we report a nonredundant NFAT-dependent role for lipid-derived leukotrienes (LTs) in the activation of lung ILC2s. Using cytokine reporter and LT-deficient mice, we find that complete disruption of LT signaling markedly diminishes ILC2 activation and downstream responses during type 2 inflammation. Type 2 responses are equivalently attenuated in IL-33- and LT-deficient mice, and optimal ILC2 activation reflects potent synergy between these pathways. These findings expand our understanding of ILC2 regulation and may have important implications for the treatment of airways disease
Nonequilibrium theory of Coulomb blockade in open quantum dots
We develop a non-equilibrium theory to describe weak Coulomb blockade effects
in open quantum dots. Working within the bosonized description of electrons in
the point contacts, we expose deficiencies in earlier applications of this
method, and address them using a 1/N expansion in the inverse number of
channels. At leading order this yields the self-consistent potential for the
charging interaction. Coulomb blockade effects arise as quantum corrections to
transport at the next order. Our approach unifies the phase functional and
bosonization approaches to the problem, as well as providing a simple picture
for the conductance corrections in terms of renormalization of the dot's
elastic scattering matrix, which is obtained also by elementary perturbation
theory. For the case of ideal contacts, a symmetry argument immediately allows
us to conclude that interactions give no signature in the averaged conductance.
Non-equilibrium applications to the pumped current in a quantum pump are worked
out in detail.Comment: Published versio
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