751 research outputs found
Motion of nanodroplets near chemical heterogeneities
We investigate the dynamics of nanoscale droplets in the vicinity of chemical
steps which separate parts of a substrate with different wettabilities. Due to
long-ranged dispersion forces, nanodroplets positioned on one side of the step
perceive the different character of the other side even at some distances from
the step, leading to a dynamic response. The direction of the ensuing motion of
such droplets does not only depend on the difference between the equilibrium
contact angles on these two parts but in particular on the difference between
the corresponding Hamaker constants. Therefore the motion is not necessarily
directed towards the more wettable side and can also be different from that of
droplets which span the step.Comment: 6 pages, 6 figure
Motion of nanodroplets near edges and wedges
Nanodroplets residing near wedges or edges of solid substrates exhibit a
disjoining pressure induced dynamics. Our nanoscale hydrodynamic calculations
reveal that non-volatile droplets are attracted or repelled from edges or
wedges depending on details of the corresponding laterally varying disjoining
pressure generated, e.g., by a possible surface coating.Comment: 12 pages, 7 figure
On the feasibility of attribute-based encryption on Internet of Things devices
Attribute-based encryption (ABE) could be an effective cryptographic tool for the secure management of Internet of Things (IoT) devices, but its feasibility in the IoT has been under-investigated thus far. This article explores such feasibility for well-known IoT platforms, namely, Intel Galileo Gen 2, Intel Edison, Raspberry pi 1 model B, and Raspberry pi zero, and concludes that adopting ABE in the IoT is indeed feasible
The algebraic hyperstructure of elementary particles in physical theory
Algebraic hyperstructures represent a natural extension of classical
algebraic structures. In a classical algebraic structure, the composition of
two elements is an element, while in an algebraic hyperstructure, the
composition of two elements is a set. Algebraic hyperstructure theory has a
multiplicity of applications to other disciplines. The main purpose of this
paper is to provide examples of hyperstructures associated with elementary
particles in physical theory.Comment: 13 page
Experimental Validation of a Dynamic Model for Lightweight Robots
Nowadays, one of the main topics in robotics research is dynamic performance improvement by means of a lightening of the overall system structure.
The effective motion and control of these lightweight robotic systems occurs with the use of suitable motion planning and control process. In order to do so, model-based approaches can be adopted by exploiting accurate dynamic models that take into account the inertial and elastic terms that are usually neglected in a heavy rigid link configuration.
In this paper, an effective method for modelling spatial lightweight industrial robots based on an Equivalent Rigid Link System approach is considered from an experimental validation perspective.
A dynamic simulator implementing the formulation is used and an experimental test-bench is set-up.
Experimental tests are carried out with a benchmark L-shape mechanism
Incorporating tool deformation in the design of extrusion dies for complex hollow profiles
The potential of OpenFOAM to design extrusion dies, incorporating the Fluid Structure Interaction (FSI)Fundação para a Ciência e a Tecnologia (FCT) - FCOMP-01-0124-FEDER-015126 (Refª. FCT PTDC/EMEMFE/
113988/2009), FCOMP-01-0124-FEDER-010190 (Refª. FCT PTDC/EME-FME/102729/2008)
and PEst-C/CTM/LA0025/2011 (Strategic Project - LA 25 – 2011-2012), SFRH/BD43632/2008, FCT-SFRH/ BPD/ 77467/ 201
Thermal inactivation and conformational lock studies on glucose oxidase
In this study, the dissociative thermal inactivation
and conformational lock theories are applied for the
homodimeric enzyme glucose oxidase (GOD) in order to
analyze its structure. For this purpose, the rate of activity
reduction of glucose oxidase is studied at various temperatures
using b-D-glucose as the substrate by incubation of
enzyme at various temperatures in the wide range between
40 and 70 �C using UV–Vis spectrophotometry. It was
observed that in the two ranges of temperatures, the
enzyme has two different forms. In relatively low temperatures,
the enzyme is in its dimeric state and has normal
activity. In high temperatures, the activity almost disappears
and it aggregates. The above achievements are confirmed
by dynamic light scattering. The experimental
parameter ‘‘n’’ as the obvious number of conformational
locks at the dimer interface of glucose oxidase is obtained
by kinetic data, and the value is near to two. To confirm the
above results, the X-ray crystallography structure of the
enzyme, GOD (pdb, 1gal), was also studied. The secondary
and tertiary structures of the enzyme to track the thermal
inactivation were studied by circular dichroism and
fluorescence spectroscopy, respectively. We proposed a
mechanism model for thermal inactivation of GOD based
on the absence of the monomeric form of the enzyme by
circular dichroism and fluorescence spectroscopy
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