11,077 research outputs found
Analyzing the 3D Printed Material Tango Plus FLX930 for Using in Self-Folding Structure
Self-folding is the ability of the structure to fold and/or unfold without human intervention or any application of external manipulation. It is known that the structure of folding object consists of two essential parts. These parts are the faces and the creases. In this paper, it is assumed that the faces could be built by using solid materials, and the crease lines can be built using soft material which provides a high bent ability. Furthermore, these two materials should be combined built without using any connections between them. Fortunately, the 3D printer provides this capability. It can print two types of different materials at the same time for the same structure. Therefore, a 3D printer is chosen to fabricate a folding structure using two types of material. These types are the Vero for solid faces and Tango plus FLX930 for the soft creases lines. The soft material at hinge part (creases lines) subjected to the load directly when the structure folds. It should have a clear view of the mechanical properties of this material. Therefore, several mechanical tests for Tango FLX930 material are operated to calculate its mechanical properties and find the force that required to fold it
HyperLoom: A platform for defining and executing scientific pipelines in distributed environments
Real-world scientific applications often encompass end-to-end data processing pipelines composed of a large number of interconnected computational tasks of various granularity. We introduce HyperLoom, an open source platform for defining and executing such pipelines in distributed environments and providing a Python interface for defining tasks. HyperLoom is a self-contained system that does not use an external scheduler for the actual execution of the task. We have successfully employed HyperLoom for executing chemogenomics pipelines used in pharmaceutic industry for novel drug discovery.6
Variations in slow slip moment rate associated with rapid tremor reversals in Cascadia
During large slow slip events, tremor sometimes propagates in the reverse along-strike direction for a few hours, at speeds 10 to 40 times faster than the forward propagation. We examine the aseismic slip that underlies this rapidly propagating tremor. We use PBO (Plate Boundary Observatory) borehole strainmeter data to search for variations in the slow slip moment rate during 35 rapid tremor reversals (RTRs) that occurred beneath Vancouver Island. The strain records reveal that, on average, the strain rate increases by about 100% ( math formula) during RTRs. Given the Green's functions expected for slip in the RTR locations, these strain rate increases imply 50 to 130% increases in the aseismic moment rate. The median moment released per RTR is between 8 and 21% of the daily slow slip moment, equivalent to that of a MW 5.0 to 5.1 earthquake. By combining the RTR moments with the spatial extents suggested by tremor, we estimate that a typical RTR has peak slip of roughly one-sixth of the peak slip in the main slow slip event, near-front slip rate of a few to ten times the main front slip rate, stress drop around half the main event stress drop, and strain energy release rate around one-tenth that of the main front. Our observations support a picture of RTRs as aseismic subevents with high slip rates but modest strain energy release. RTRs appear to contribute to but not dominate the overall slow slip moment, though they may accommodate most of the slip in certain locations
Non Abelian Geometrical Tachyon
We investigate the dynamics of a pair of coincident D5 branes in the
background of NS5 branes. It has been proposed by Kutasov that the system
with a single probing D-brane moving radially in this background is dual to the
tachyonic DBI action for a non-BPS Dp brane. We extend this proposal to the
non-abelian case and find that the duality still holds provided one promotes
the radial direction to a matrix valued field associated with a non-abelian
geometric tachyon and a particular parametrization for the transverse scalar
fields is chosen. The equations of motion of a pair of coincident D5 branes
moving in the NS5 background are determined. Analytic and numerical solutions
for the pair are found in certain simplified cases in which the U(2) symmetry
is broken to corresponding to a small transverse separation
of the pair. For certain range of parameters these solutions describe periodic
motion of the centre of mass of the pair 'bouncing off' a finite sized throat
whose minimum size is limited by the D5 branes separation.Comment: 18 pages, 2 figures, PdfLatex: references added.accepted for
publication in JHE
Influence of wave spreading on offshore wind turbine design: IEA 15-MW scenario
Offshore ocean waves are directionally spread, whereby the propagation of energy travels in different directions. Despite this multi-directionality, the use of 3-dimensional wave models for loading on fixed offshore wind turbines has been limited. This is partially due to the common assumption that uni-directional sea-states are conservative within a design philosophy. This may not always be true given that in operating conditions the amount of aerodynamic damping in the side-side direction is much lower than the fore-aft direction. This paper aims to address this issue by providing the influence of wave spreading on various offshore wind turbine design scenarios: fatigue, ultimate and service limit state design. This study demonstrates that wave spreading indeed results in more fatigue damage for operating load cases. Despite this, the overall fatigue and ultimate limit state utilisation is still reduced when a wave spreading is adopted
Assessing the Health Impact of Water Quality Interventions in Low-Income Settings: Concerns Associated with Blinded Trials and the Need for Objective Outcomes.
BACKGROUND: A dramatic disparity between the results of blinded versus open trial designs has raised questions about the effectiveness of water quality interventions and other environmental interventions to prevent diarrhea, a leading killer of young children in low-income countries. OBJECTIVES: We summarize the results of blinded versus open trials of water quality interventions, describe evidence from a recent placebo-controlled trial in India suggesting that control households were put at risk from their participation, and suggest alternatives to blinded trials that could resolve continued uncertainty about the magnitude of the protective effect of water, sanitation, and hygiene (WASH) interventions without presenting ethical questions. DISCUSSION: Concerns about reporting bias in open trial designs continue to cause uncertainty about the effectiveness of WASH interventions. However, evidence suggests that despite instructions to the contrary, placebos may encourage control group participants in blinded trials to cease practicing traditional water treatment practices in the mistaken belief that they are protected by an active intervention. Although objective outcomes such as pathogen incrimination, seroconversion, biomarkers, and anthropometry can be helpful, these are often costly, nonspecific, and unsuitable for evaluating programmatic interventions. CONCLUSIONS: Unless researchers can be assured that a placebo will not cause those in a control group to change their behavior in a manner that increases their risk, it is incumbent on researchers to use alternatives. Validated objective measures are needed for assessing the health impact of WASH interventions that are reliable, affordable, and suitable both for research and program evaluation. CITATION: Clasen T, Boisson S. 2016. Assessing the health impact of water quality interventions in low-income settings: concerns associated with blinded trials and the need for objective outcomes. Environ Health Perspect 124:886-889; http://dx.doi.org/10.1289/ehp.1510532
Effective Field Theory and Finite Density Systems
This review gives an overview of effective field theory (EFT) as applied at
finite density, with a focus on nuclear many-body systems. Uniform systems with
short-range interactions illustrate the ingredients and virtues of many-body
EFT and then the varied frontiers of EFT for finite nuclei and nuclear matter
are surveyed.Comment: 27 pages, 5 figure
Convective intensification of magnetic fields in the quiet Sun
Kilogauss-strength magnetic fields are often observed in intergranular lanes at the photosphere in the quiet Sun. Such fields are stronger than the equipartition field B_e, corresponding to a magnetic energy density that matches the kinetic energy density of photospheric convection, and comparable with the field B_p that exerts a magnetic pressure equal to the ambient gas pressure. We present an idealised numerical model of three-dimensional compressible magnetoconvection at the photosphere, for a range of values of the magnetic Reynolds number. In the absence of a magnetic field, the convection is highly supercritical and is characterised by a pattern of vigorous, time-dependent, “granular” motions. When a weak magnetic field is imposed upon the convection, magnetic flux is swept into the convective downflows where it forms localised concentrations. Unless this process is significantly inhibited by magnetic diffusion, the resulting fields are often much greater than B_e, and the high magnetic pressure in these flux elements leads to their being partially evacuated. Some of these flux elements contain ultra-intense magnetic fields that are significantly greater than B_p. Such fields are contained by a combination of the thermal pressure of the gas and the dynamic pressure of the convective motion, and they are constantly evolving. These ultra-intense fields develop owing to nonlinear interactions between magnetic fields and convection; they cannot be explained in terms of “convective collapse” within a thin flux tube that remains in overall pressure equilibrium with its surroundings
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