151 research outputs found
Tunable morphing of electroactive dielectric-elastomer balloons
Designing smart devices with tunable shapes has important applications in
industrial manufacture. In this paper, we investigate the nonlinear deformation
and the morphological transitions between buckling, necking, and snap-through
instabilities of layered DE balloons in response to an applied radial voltage
and an inner pressure. We propose a general mathematical theory of nonlinear
electro-elasticity able to account for finite inhomogeneous strains provoked by
the electro-mechanical coupling. We investigate the onsets of morphological
transitions of the spherically symmetric balloons using the surface impedance
matrix method. Moreover, we study the nonlinear evolution of the bifurcated
branches through finite element numerical simulations. Our analysis
demonstrates the possibility to design tunable DE spheres, where the onset of
buckling and necking can be controlled by geometrical and mechanical properties
of the passive elastic layers. Relevant applications include soft robotics and
mechanical actuators
Effect of steam hydration on reactivity and strength of cement-supported calcium sorbents for CO2 capture
Steam hydration was used to reactivate spent cement-supported CO2 sorbent pellets for recycle and the effect of steam hydration on the reactivity of sorbents was investigated in a bubbling fluidised reactor. A specially designed impact apparatus was developed to evaluate the strength of the reactivated pellets as well as determine the effect of “superheating”. It was found that the reactivity of synthetic pellets was significantly elevated over that of raw limestone after steam hydration. The CaO conversion of spent pellets increased from 0.113 to 0.419 after hydration, whereas that of spent limestone ranged from 0.089 to 0.278. The CaO conversions of hydrated samples calcined under different conditions achieved the identical level, proportional to the degree of hydration. As expected, the mechanical strength of synthetic pellets declined severely after reactivation. Large cracks emerged on hydrated limestone as seen in scanning electron microscope images. By contrast, similar cracks were not observed for synthetic pellets after hydration, although hydration did produce higher porosity than seen with limestone and an increased surface area, which enhanced CO2 capacity and was associated with an increase in strength loss. The breakage rate of superheated steam-reactivated limestone derived pellets was about half that of hydrated samples. This demonstrates that superheating treatment (which allows the annealing of stacking faults and mechanical strain produced by hydration) enhances the strength of hydrated pellets. This work demonstrated that combining steam hydration with superheating can both reactivate the spent synthetic pellets and reduce strength decay associated with the hydration process
N′-[(2-Hydroxynaphthalen-1-yl)methylidene]-4-nitrobenzohydrazide
In the title molecule, C18H13N3O4, the hydroxy group is involved in the formation of an intramolecular O—H⋯N hydrogen bond. The dihedral angle between the planes of the benzene ring and the naphthyl ring system is 9.0 (2)°. In the crystal, molecules are linked through N—H⋯O hydrogen bonds into chains along the c axis
Hybrid genetic algorithm based on bin packing strategy for the unrelated parallel workgroup scheduling problem
The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.In this paper we focus on an unrelated parallel workgroup scheduling problem
where each workgroup is composed of a number of personnel with similar work
skills which has eligibility and human resource constraints. The most difference
from the general unrelated parallel machine scheduling with resource constraints
is that one workgroup can process multiple jobs at a time as long as the resources
are available, which means that a feasible scheduling scheme is impossible to get
if we consider the processing sequence of jobs only in time dimension. We
construct this problem as an integer programming model with the objective of
minimizing makespan. As it is incapable to get the optimal solution in the
acceptable time for the presented model by exact algorithm, meta-heuristic is
considered to design. A pure genetic algorithm based on special coding design is
proposed firstly. Then a hybrid genetic algorithm based on bin packing strategy is
further developed by the consideration of transforming the single workgroup
scheduling to a strip-packing problem. Finally, the proposed algorithms, together
with exact approach, are tested at different size of instances. Results demonstrate
that the proposed hybrid genetic algorithm shows the effective performance
CO2 capture performance using biomass-templated cement-supported limestone pellets
Synthetic biomass-templated cement-supported CaO-based sorbents were produced by granulation
process for high-temperature post-combustion CO2 capture. Commercial flour was used as the biomass
and served as a templating agent. The investigation of porosity showed that the pellets with biomass or
cement resulted in enhancement of porosity. Four types of sorbents containing varying proportions of
biomass and cement were subject to 20 cycles in a TGA under different calcination conditions. After
first series of tests calcined at 850 °C in 100% N2, all composite sorbents clearly exhibited higher CO2
capture activity compared to untreated limestone with exception of sorbents doped by seawater. The
biomass-templated cement-supported pellets exhibited the highest CO2 capture level of 46.5% relative
to 20.8% for raw limestone after 20 cycles. However, the observed enhancement in performance was
substantially reduced under 950 °C calcination condition. Considering the fact that both sorbents
supported by cement exhibited relatively high conversion with a maximum value of 19.5%, cement
promoted sorbents appear to be better at resisting of harsh calcination conditions. Although flour as
biomass-templated material generated significantly enhancement in CO2 capture capacity, further
exploration must be carried out to find the way of maintaining outstanding performance for CaO-based
sorbents under severe reaction conditions
Message-passing selection: Towards interpretable GNNs for graph classification
In this paper, we strive to develop an interpretable GNNs' inference
paradigm, termed MSInterpreter, which can serve as a plug-and-play scheme
readily applicable to various GNNs' baselines. Unlike the most existing
explanation methods, MSInterpreter provides a Message-passing Selection
scheme(MSScheme) to select the critical paths for GNNs' message aggregations,
which aims at reaching the self-explaination instead of post-hoc explanations.
In detail, the elaborate MSScheme is designed to calculate weight factors of
message aggregation paths by considering the vanilla structure and node
embedding components, where the structure base aims at weight factors among
node-induced substructures; on the other hand, the node embedding base focuses
on weight factors via node embeddings obtained by one-layer GNN.Finally, we
demonstrate the effectiveness of our approach on graph classification
benchmarks.Comment: 6 pages, 1 figure
Electrolyte influence on sorption behaviours of Direct Blue 71 dye on ramie fibre
Ramie loose fibre was dyed using Direct Blue 71 dye at 70, 80, 90 and 100°C without and with NaCl electrolyte in order to investigate the distinction of dye sorption behaviours. The results show that the dye exhaustion increases with addition of NaCl and shortens the equilibrium dyeing time. The dye adsorption process of dyeing without and with NaCl followed pseudo second-order kinetics, but the rate constant of sorption is larger for the latter compared to the former
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