285,065 research outputs found
Dual functionality anti-reflection and biocidal coatings
A thin film combination of anti-reflection (AR) and biocidal properties would be of particular interest to reduce the transfer of infection and improve readability of public high use touch screens. In this paper we describe the development of a dual functionality film of silica (AR) and copper oxide (biocidal). Deposition was via flame assisted chemical vapour deposition (FACVD) which has the advantages of being a cost efficient atmospheric pressure technique enabling use of non-volatile precursors and that no closed reaction cell is required so making it ideal for integration into industrial production lines. The resulting films were characterized by a range of techniques including optical spectroscopy, electron microscope and X-ray fluorescence. Biocidal behavior was tested by determining the kill rate of Escherichia coli.
A 3 layer stack on glass of silica/copper oxide/silica had better adhesion and lower reflection than a comparable 2 layer stack. This multilayer film led to a > 2% drop in reflection from that of uncoated glass, similar to that of silica only film. In addition, showed a > 6 log10 kill between 6 and 24 h for as deposited and annealed samples
Autonomous Dynamics in Neural networks: The dHAN Concept and Associative Thought Processes
The neural activity of the human brain is dominated by self-sustained
activities. External sensory stimuli influence this autonomous activity but
they do not drive the brain directly. Most standard artificial neural network
models are however input driven and do not show spontaneous activities.
It constitutes a challenge to develop organizational principles for
controlled, self-sustained activity in artificial neural networks. Here we
propose and examine the dHAN concept for autonomous associative thought
processes in dense and homogeneous associative networks. An associative
thought-process is characterized, within this approach, by a time-series of
transient attractors. Each transient state corresponds to a stored information,
a memory. The subsequent transient states are characterized by large
associative overlaps, which are identical to acquired patterns. Memory states,
the acquired patterns, have such a dual functionality.
In this approach the self-sustained neural activity has a central functional
role. The network acquires a discrimination capability, as external stimuli
need to compete with the autonomous activity. Noise in the input is readily
filtered-out.
Hebbian learning of external patterns occurs coinstantaneous with the ongoing
associative thought process. The autonomous dynamics needs a long-term
working-point optimization which acquires within the dHAN concept a dual
functionality: It stabilizes the time development of the associative thought
process and limits runaway synaptic growth, which generically occurs otherwise
in neural networks with self-induced activities and Hebbian-type learning
rules
Optimum design of a probe fed dual frequency patch antenna using genetic algorithm
Abstract: Recent research has concentrated on different designs in order to increase the bandwidth of patch antennas and thus improve functionality of wireless communication systems. An alternative approach as shown in this paper is to design a matched probe fed rectangular patch antenna which can operate at both dual frequency (1.9 GHz and 2.4 GHz) and dual polarisation. In this design there are four variables, the two dimensions of the rectangular patch, ‘a ’ and ‘b ’ and position of the probe feed ‘Xp ’ and ‘YP’. As there is not a unique solution Genetic Algorithm (GA) was applied using two objective functions for the return loss at each frequency. The antenna was then modelled using AWR software and the predicted and practical results are shown to be in good agreement. Key Words: Genetic algorithm (GA), dual frequency, dual polarisation, probe fed patch antenn
Plasmonic nanogap enhanced phase change devices with dual electrical-optical functionality
Modern-day computers use electrical signaling for processing and storing data
which is bandwidth limited and power-hungry. These limitations are bypassed in
the field of communications, where optical signaling is the norm. To exploit
optical signaling in computing, however, new on-chip devices that work
seamlessly in both electrical and optical domains are needed. Phase change
devices can in principle provide such functionality, but doing so in a single
device has proved elusive due to conflicting requirements of size-limited
electrical switching and diffraction-limited photonic devices. Here, we combine
plasmonics, photonics and electronics to deliver a novel integrated
phase-change memory and computing cell that can be electrically or optically
switched between binary or multilevel states, and read-out in either mode, thus
merging computing and communications technologies
Flexible dual-diversity wearable wireless node integrated on a dual-polarised textile patch antenna
A new textile wearable wireless node, for operation in the 2.45 GHz industrial, scientific and medical (ISM) band, is proposed. It consists of a dual-polarised textile patch antenna with integrated microcontroller, sensor, memory and transceiver with receive diversity. Integrated into a garment, the flexible unit may serve for fall detection, as well as for patient or rescue-worker monitoring. Fragile and lossy interconnections are eliminated. They are replaced by very short radiofrequency signal paths in the antenna feed plane, reducing electromagnetic compatibility and signal integrity problems. The compact and flexible module combines sensing and wireless channel monitoring functionality with reliable and energy-efficient off-body wireless communication capability, by fully exploiting dual polarisation diversity. By integrating a battery, a fully autonomous and flexible system is obtained. This novel textile wireless node was validated, both in flat and bent state, in the anechoic chamber, assessing the characteristics of the integrated system in free-space conditions. Moreover, its performance was verified in various real-world conditions, integrated into a firefighter garment, and used as an autonomous body-centric measurement device
Polymeric blends for sensor and actuation dual functionality
The invention described herein supplies a new class of electroactive polymeric blend materials which offer both sensing and actuation dual functionality. The blend comprises two components, one component having a sensing capability and the other component having an actuating capability. These components should be co-processable and coexisting in a phase separated blend system. Specifically, the materials are blends of a sensing component selected from the group consisting of ferroelectric, piezoelectric, pyroelectric and photoelectric polymers and an actuating component that responds to an electric field in terms of dimensional change. Said actuating component includes, but is not limited to, electrostrictive graft elastomers, dielectric electroactive elastomers, liquid crystal electroactive elastomers and field responsive polymeric gels. The sensor functionality and actuation functionality are designed by tailoring the relative fraction of the two components. The temperature dependence of the piezoelectric response and the mechanical toughness of the dual functional blends are also tailored by the composition adjustment
Annealing stability of magnetic tunnel junctions based on dual MgO free layers and [Co/Ni] based thin synthetic antiferromagnet fixed system
We study the annealing stability of bottom-pinned perpendicularly magnetized
magnetic tunnel junctions based on dual MgO free layers and thin fixed systems
comprising a hard [Co/Ni] multilayer antiferromagnetically coupled to thin a Co
reference layer and a FeCoB polarizing layer. Using conventional magnetometry
and advanced broadband ferromagnetic resonance, we identify the properties of
each sub-unit of the magnetic tunnel junction and demonstrate that this
material option can ensure a satisfactory resilience to the 400C
thermal annealing needed in solid-state magnetic memory applications. The dual
MgO free layer possesses an anneal-robust 0.4 T effective anisotropy and
suffers only a minor increase of its Gilbert damping from 0.007 to 0.010 for
the toughest annealing conditions. Within the fixed system, the ferro-coupler
and texture-breaking TaFeCoB layer keeps an interlayer exchange above 0.8
mJ/m, while the Ru antiferrocoupler layer within the synthetic
antiferromagnet maintains a coupling above -0.5 mJ/m. These two strong
couplings maintain the overall functionality of the tunnel junction upon the
toughest annealing despite the gradual degradation of the thin Co layer
anisotropy that may reduce the operation margin in spin torque memory
applications. Based on these findings, we propose further optimization routes
for the next generation magnetic tunnel junctions
Dual Attention Network for Product Compatibility and Function Satisfiability Analysis
Product compatibility and their functionality are of utmost importance to
customers when they purchase products, and to sellers and manufacturers when
they sell products. Due to the huge number of products available online, it is
infeasible to enumerate and test the compatibility and functionality of every
product. In this paper, we address two closely related problems: product
compatibility analysis and function satisfiability analysis, where the second
problem is a generalization of the first problem (e.g., whether a product works
with another product can be considered as a special function). We first
identify a novel question and answering corpus that is up-to-date regarding
product compatibility and functionality information. To allow automatic
discovery product compatibility and functionality, we then propose a deep
learning model called Dual Attention Network (DAN). Given a QA pair for a
to-be-purchased product, DAN learns to 1) discover complementary products (or
functions), and 2) accurately predict the actual compatibility (or
satisfiability) of the discovered products (or functions). The challenges
addressed by the model include the briefness of QAs, linguistic patterns
indicating compatibility, and the appropriate fusion of questions and answers.
We conduct experiments to quantitatively and qualitatively show that the
identified products and functions have both high coverage and accuracy,
compared with a wide spectrum of baselines
- …
